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17:00:02 1511071       AIClient - Request to AI with prompt: 'please check if the given text is spam. answer with yes or no.' and documents [Imported from: /opt/downloadPDF/chemwiki_pubstore/3367bc96dd5ea3f6f066a72bda21db9d.pdf/41467_2023_36784_MOESM1_ESM_6a9ab628c555c.pdf /opt/downloadPDF/chemwiki_pubstore/3367bc96dd5ea3f6f066a72bda21db9d.pdf/Lei et al. - 2023 - Photocatalytic CO2 reduction with aminoanthraquinone organic dyes_6a9ab628c72a1.pdf Contents 1 Abstract Summary 2 Advances and Special Progress 3 Additional Remarks 4 Content of the Published Article in Detail 5 Catalyst 6 Photosensitizer 7 Investigation Abstract Summary[edit | edit source] This article describes a homogeneous molecular photocatalytic system for reducing CO2 to CO under visible light using aminoanthraquinone organic dyes as photosensitizers and an iron porphyrin complex as the catalyst. The system uses a sacrificial organic electron donor in DMF solution under CO2. The main finding is that aminoanthraquinone dyes can drive highly selective CO formation, and that one dye in particular, PS 5, gives especially high activity. The study reports high turnover numbers for both the photosensitizer and the catalyst in separate benchmark conditions, while mechanistic experiments support a reductive-quenching pathway and implicate reduced hydroxyanthrone-type dye intermediates in catalyst reduction. Advances and Special Progress[edit | edit source] A key advance is the use of simple aminoanthraquinone organic dyes as efficient visible-light absorbers for molecular CO2 photoreduction. The article explicitly emphasizes that these systems avoid precious-metal photosensitizers and use commercially available organic dyes together with an iron porphyrin catalyst. Another important advance is the simultaneous demonstration of high activity metrics for both the catalyst and the photosensitizer, although these were established under different optimized concentration regimes. Under one condition, PS 5 with FeTDHPP gave a catalyst-based turnover number for CO of 21,616. Under another, the same dye gave a photosensitizer-based turnover number for CO of 6012. The article states that achieving high activity for both components has not been realized in current light-driven systems of this type. The work also provides mechanistic progress. Structure–function comparison across dyes 1–6 supports the idea that a built-in donor–acceptor character within the aminoanthraquinone framework promotes faster reductive quenching and higher catalytic rates. The study further proposes that hydroxyanthrone-derived reduced species formed after light-driven proton-coupled reduction of the dye are key intermediates for reducing the iron catalyst to catalytically relevant low-valent states. CO selectivity is another notable feature. The systems with PSs 1–5 gave CO as the major product with selectivities above 99%, while H2 formation was strongly suppressed. The reported quantum efficiency for CO production reached 11.1% at 450 nm for PS 5 under the stated conditions. Additional Remarks[edit | edit source] The chemistry is significant because it addresses solar-to-chemical conversion of CO2 using molecular components made from earth-abundant elements at the catalytic center and organic dyes as light harvesters. The work is therefore relevant to the broader challenge of replacing noble-metal photosensitizers in artificial photosynthesis. At the same time, the study is a sacrificial photochemical system rather than a fully integrated sustainable fuel-forming device. It requires BIH as a sacrificial electron donor and uses DMF as the reaction medium. No water-compatible operating window is established as a main feature of this system, and the article does not present this work as a water-based photocatalytic platform. The system is chemically selective for CO over H2, but durability remains limited by decomposition, especially of the iron porphyrin catalyst. Component-addition experiments showed that activity loss is associated mainly with catalyst decomposition rather than simple BIH depletion or rapid dye decomposition. This is mechanistically informative but also identifies a practical limitation. The article combines strong photocatalytic performance with detailed mechanistic analysis. Its strength lies in connecting substituent effects on the organic dyes with measurable quenching behavior, redox chemistry, photochemical intermediates, and catalytic output. Its limitations include reliance on a sacrificial donor, use of an aprotic organic solvent, and incomplete long-term stability. Content of the Published Article in Detail[edit | edit source] The photocatalytic system contains three essential molecular components: an aminoanthraquinone photosensitizer, the iron porphyrin catalyst FeTDHPP, and the sacrificial electron donor BIH. The reaction medium is CO2-saturated DMF, and irradiation is typically provided by white LED light with λ > 400 nm. Gas products are analyzed from the headspace, and CO is reported as the main product. The article compares six aminoanthraquinone dyes, labeled 1–6. These dyes absorb across the visible region, with absorption maxima spanning 478–592 nm. They emit red fluorescence in the 600–700 nm region with lifetimes of 0.66–1.02 ns. Electrochemical measurements show two reduction events for each dye. The authors use these photophysical and electrochemical data to justify their use as reductively quenched organic photosensitizers. In the main catalytic comparison, the authors examined CO2 reduction with 20 μM photosensitizer, 0.6 μM FeTDHPP, and 60 mM BIH. Under these conditions, all six dyes gave CO as the major product, but their activities differed substantially. PS 5 was the most active, reaching a catalyst-based turnover number for CO of 21,616, while PS 4 was the next strongest at 8360. PSs 1–3 were less active, and PS 6 was markedly poorer. The article relates these differences to substituent effects within the anthraquinone framework. To evaluate photosensitizer endurance and efficiency separately, the authors also used conditions with high catalyst concentration and low dye concentration. With 20 μM FeTDHPP, 5 μM photosensitizer, and 60 mM BIH, PS 5 gave a photosensitizer-based turnover number for CO of 6012. PS 4 again performed strongly, while the others were lower. The article further reports experiments in which PS 5 and FeTDHPP were used at the same concentration. Under these matched conditions, the system achieved a CO turnover number of 4978 and a quantum efficiency of 11.1% at 450 nm, based on two photons per CO. This is presented as evidence that both light harvesting and catalytic reduction are efficient in this molecular combination. Mechanistically, the article argues that the system operates mainly through reductive quenching rather than oxidative quenching. The evidence includes the very high concentration of BIH relative to FeTDHPP, fluorescence lifetime quenching by BIH near the diffusion-controlled limit, and the lack of evidence for ground-state reaction between the dyes and either BIH or FeTDHPP in UV/Vis and 1H NMR studies. Because spectral overlap prevented accurate determination of oxidative quenching constants, the oxidative pathway is not completely excluded experimentally, but the data are interpreted in favor of reductive quenching as the dominant route. The authors also note that aminoanthraquinones can undergo excited-state intramolecular proton transfer, which complicated interpretation of steady-state emission quenching. For that reason, they relied on fluorescence lifetime measurements to determine quenching rate constants. These rate constants were all greater than 109 M−1 s−1, and the initial catalytic turnover frequencies showed a generally linear trend with these quenching constants. A central mechanistic feature is the photochemical reduction and protonation sequence of the anthraquinone dyes. To probe this, the article studies anthraquinone itself as a model. Under irradiation in the presence of BIH, UV/Vis spectroscopy showed formation of transient species assigned by the authors to AQH•, AQH−, AQH2, and eventually a more reduced species absorbing near 400 nm. By analogy, related intermediates are proposed for PSs 1–6. The article proposes that after reductive quenching and proton-coupled reduction, the photosensitizer forms a hydroxyanthrone-type intermediate PSH2. Further excitation and reduction then generate PSH2−. This reduced hydroxyanthrone-type species is proposed to be the key reductant that transfers electrons to the iron catalyst. This proposal is supported by several observations: a ~400 nm photoproduct accumulates during photolysis; adding FeTDHPP to a pre-irradiated solution of PS 5 and BIH caused rapid CO formation and formation of an Fe(I) species; and in situ square-wave voltammetry showed new reduction waves at potentials more negative than −1.90 V vs SCE after irradiation, consistent with a strongly reducing photoproduct. The iron catalyst undergoes stepwise photoreduction. UV/Vis experiments under white light showed conversion of Fe(III) to Fe(II) within minutes, followed by formation of Fe(I). The article notes that CO2 reduction by FeTDHPP is associated with an Fe(0) state, and proposes that PSH2− reduces Fe(II) or Fe(I) onward to Fe(0), from which CO2 reduction proceeds. Proton transfer is included in the proposed catalytic cycle, and the scheme presented by the authors includes 2 H+ in the conversion of CO2 to CO. The role of BIH is twofold in the article’s interpretation. First, BIH reductively quenches the excited photosensitizer. Second, its one-electron oxidation product BI• is considered important in the photochemical sequence that generates PSH2−. Experiments under long-wavelength irradiation (>550 nm), which suppress formation of PSH2−, gave much slower CO production and mainly Fe(II) with less Fe(I), supporting the idea that direct BI• reduction of the catalyst is much less effective than reduction mediated by the reduced hydroxyanthrone-type dye intermediate. Several control and supporting experiments strengthen the chemical interpretation. Dynamic light scattering detected no nanoparticles before or after catalysis, and mercury poisoning did not significantly suppress activity, supporting a homogeneous molecular system rather than catalysis by metal particles. Isotopic labeling under 13CO2 gave exclusive 13CO, confirming CO2 as the carbon source of the product. Stability tests in which additional components were added after activity decline showed that adding catalyst and BIH restored much more activity than adding BIH alone or photosensitizer plus BIH, indicating faster decomposition of the iron catalyst than the anthraquinone dye. Regarding side products, H2 formation was strongly suppressed in most systems. CO selectivity exceeded 99% for PSs 1–5 and was 98.5% for PS 6. The article attributes the poorer performance of PS 6 partly to its acidic sulfonyl group, which may facilitate proton transfer to the catalyst and thereby enhance H2 formation relative to the other dyes. CH4 and HCOOH are not reported as products for this aminoanthraquinone/FeTDHPP photocatalytic system. Catalyst[edit | edit source] The catalyst is FeTDHPP, an iron porphyrin complex. The article treats it as a molecular homogeneous CO2 reduction catalyst. It is used at low micromolar concentration in the main benchmarking experiments and is responsible for converting CO2 to CO after receiving electrons from reduced photosensitizer-derived intermediates. The catalyst cycles through multiple oxidation states during operation. UV/Vis experiments support formation of Fe(II) and Fe(I) during photolysis, and the article states that CO2 reduction by this catalyst occurs at an Fe(0) oxidation state. The proposed mechanism therefore involves sequential reduction of Fe(III) to Fe(II), Fe(I), and Fe(0). FeTDHPP is presented as highly selective for CO formation in this photocatalytic pairing, with H2 production largely suppressed under most conditions. However, its long-term stability is limited. Component-readdition experiments indicate that the catalyst decomposes faster than the anthraquinone dye, and this decomposition is an important cause of activity loss during prolonged irradiation. The catalyst remains molecular under the tested conditions according to the article’s control experiments. Dynamic light scattering did not reveal nanoparticle formation, and mercury poisoning did not materially change performance. These observations support homogeneous catalysis by the iron porphyrin complex rather than a heterogeneous impurity-derived pathway. Photosensitizer[edit | edit source] The photosensitizers are aminoanthraquinone organic dyes labeled 1–6. They act as visible-light absorbers and are the primary photoactive components responsible for initiating electron transfer from BIH to the catalyst. Their visible absorption maxima span from 478 to 592 nm, and they emit in the red region with nanosecond-scale lifetimes. The main photosensitizer highlighted by performance is PS 5. It gave the highest catalyst-based and photosensitizer-based turnover numbers for CO among the series and also delivered the highest reported quantum efficiency for CO production at 450 nm. PS 4 was the next strongest performer, while PS 6 was the least favorable among the hydroxy-containing derivatives. The article proposes that these dyes function mainly through reductive quenching of the excited state by BIH. Fluorescence lifetime quenching supports rapid electron transfer from BIH to excited PS. The reduced dyes then undergo proton-coupled transformations to hydroxyanthrone-type forms, and a further reduced species, written as PSH2− in the proposed mechanism, is suggested to be the active reductant for the iron catalyst. Structure matters strongly. The article explicitly interprets the substituent effects in terms of an internal donor–acceptor design within the anthraquinone framework. Amino groups are described as electron donating and hydroxyl groups as electron withdrawing on the anthraquinone core, and the best-performing dyes are those in which this asymmetry is thought to promote electron transfer. The poorer behavior of PS 6 is linked to its sulfonyl group and increased H2 selectivity. The dyes are relatively more persistent than the catalyst under reaction conditions, but they are not indefinitely stable. The system eventually loses activity, and although dye decomposition is not identified as the dominant failure pathway, the article does not claim unlimited photosensitizer durability. Investigation[edit | edit source] cat cat conc [µM] PS PS conc [mM] e-D e-D conc [M] solvent A . . . λexc [nm] . TON CO . . TON CH4 TON H2 . TON HCOOH . . 1. FeTDHPP 0.6 1 0.02 BIH 0.06 DMF >400 2395 not reported not reported not reported "not reported" is not a number. 2. FeTDHPP 20 1 0.005 BIH 0.06 DMF >400 2011 not reported not reported not reported "not reported" is not a number. 3. FeTDHPP 20 1 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 4. FeTDHPP 0.6 2 0.02 BIH 0.06 DMF >400 2738 not reported not reported not reported "not reported" is not a number. 5. FeTDHPP 20 2 0.005 BIH 0.06 DMF >400 482 not reported not reported not reported "not reported" is not a number. 6. FeTDHPP 20 2 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 7. FeTDHPP 0.6 3 0.02 BIH 0.06 DMF >400 3551 not reported not reported not reported "not reported" is not a number. 8. FeTDHPP 20 3 0.005 BIH 0.06 DMF >400 1523 not reported not reported not reported "not reported" is not a number. 9. FeTDHPP 20 3 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 10. FeTDHPP 0.6 4 0.02 BIH 0.06 DMF >400 8360 not reported not reported not reported "not reported" is not a number. 11. FeTDHPP 20 4 0.005 BIH 0.06 DMF >400 2849 not reported not reported not reported "not reported" is not a number. 12. FeTDHPP 20 4 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 13. FeTDHPP 0.5 5 0.0005 BIH 0.06 DMF >400 3174 not reported not reported not reported "not reported" is not a number. 14. FeTDHPP 0.5 5 0.02 BIH 0.06 DMF >400 19158 not reported not reported not reported "not reported" is not a number. 15. FeTDHPP 0.6 5 0.02 BIH 0.06 DMF >400 21616 not reported not reported not reported "not reported" is not a number. 16. FeTDHPP 10 5 0.005 BIH 0.06 DMF >400 2576 not reported not reported not reported "not reported" is not a number. 17. FeTDHPP 10 5 0.01 BIH 0.06 DMF >400 4028 not reported not reported not reported "not reported" is not a number. 18. FeTDHPP 10 5 0.02 BIH 0.06 DMF >400 3942 not reported not reported not reported "not reported" is not a number. 19. FeTDHPP 1 5 0.001 BIH 0.06 DMF >400 3587 not reported not reported not reported "not reported" is not a number. 20. FeTDHPP 1 5 0.02 BIH 0.06 DMF >400 17020 not reported not reported not reported "not reported" is not a number. 21. FeTDHPP 20 5 0.005 BIH 0.06 DMF >400 6012 not reported not reported not reported "not reported" is not a number. 22. FeTDHPP 20 5 0.01 BIH 0.06 DMF >400 2325 not reported not reported not reported "not reported" is not a number. 23. FeTDHPP 20 5 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 24. FeTDHPP 20 5 0.02 BIH 0.06 DMF >400 2134 not reported not reported not reported "not reported" is not a number. 25. FeTDHPP 2 5 0.002 BIH 0.06 DMF >400 3817 not reported not reported not reported "not reported" is not a number. 26. FeTDHPP 2 5 0.005 BIH 0.06 DMF >400 8780 not reported not reported not reported "not reported" is not a number. 27. FeTDHPP 2 5 0.015 BIH 0.06 DMF >400 8772 not reported not reported not reported "not reported" is not a number. 28. FeTDHPP 2 5 0.01 BIH 0.06 DMF >400 5593 not reported not reported not reported "not reported" is not a number. 29. FeTDHPP 2 5 0.02 BIH 0.06 DMF >400 11250 not reported not reported not reported "not reported" is not a number. 30. FeTDHPP 50 5 0.02 BIH 0.06 DMF >400 891 not reported not reported not reported "not reported" is not a number. 31. FeTDHPP 5 5 0.005 BIH 0.06 DMF >400 4978 not reported not reported not reported "not reported" is not a number. 32. FeTDHPP 5 5 0.01 BIH 0.06 DMF >400 4128 not reported not reported not reported "not reported" is not a number. 33. FeTDHPP 0.6 6 0.02 BIH 0.06 DMF >400 907 not reported not reported not reported "not reported" is not a number. 34. FeTDHPP 20 6 0.005 BIH 0.06 DMF >400 1183 not reported not reported not reported "not reported" is not a number. 35. FeTDHPP 20 6 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. Investigation-Name: inv0ExportRefresh]
17:00:04 1511071       AIClient - Response from AI: No
17:00:07 1511071       AIClient - Request to AI with prompt: 'please check if the given text is spam. answer with yes or no.' and documents [Imported from: /opt/downloadPDF/chemwiki_pubstore/7e9875d2bdb7974d9ffecb4b0a29f8f5.pdf/41467_2023_36784_MOESM1_ESM_6a9ab6d0777f3.pdf /opt/downloadPDF/chemwiki_pubstore/7e9875d2bdb7974d9ffecb4b0a29f8f5.pdf/Lei et al. - 2023 - Photocatalytic CO2 reduction with aminoanthraquinone organic dyes_6a9ab6d079463.pdf DOI could not be found: 10.1038/s41467-023-36784-7-3 Contents 1 Abstract Summary 2 Advances and Special Progress 3 Additional Remarks 4 Content of the Published Article in Detail 5 Catalyst 6 Photosensitizer 7 Investigation Abstract Summary[edit | edit source] This article describes a molecular photocatalytic system for the reduction of CO2 to CO using an iron porphyrin catalyst together with aminoanthraquinone organic dyes as visible-light photosensitizers. The system operates in CO2-saturated DMF with BIH as a sacrificial electron donor under visible irradiation. A series of six aminoanthraquinone dyes was compared, and the most active dye gave high activity together with very high CO selectivity. The work also presents mechanistic evidence that reductive quenching of the excited dye is the dominant photochemical entry step, and that reduced hydroxyanthrone-type dye species are important intermediates in delivering electrons to the iron catalyst. Advances and Special Progress[edit | edit source] A central advance is the use of simple aminoanthraquinone organic dyes as effective visible-light photosensitizers in a noble-metal-free molecular CO2 reduction system. The article emphasizes that both the catalyst and the photosensitizer can reach high turnover numbers, which it states had not been achieved in current light-driven systems of this type. The study also shows a clear structure–function relationship within a small, chemically related dye family. Changing substituents on the anthraquinone framework strongly changes photocatalytic activity. The article interprets this trend in terms of built-in donor–acceptor character within the dye, which promotes faster reductive quenching and better photocatalytic performance. Another advance is the mechanistic analysis. The article combines fluorescence quenching, lifetime measurements, UV/Vis monitoring during photolysis, electrochemical measurements, isotopic labeling, DLS, and mercury poisoning tests. These data support a homogeneous molecular system and provide evidence for reduced dye-derived intermediates that participate in catalyst reduction. The reported product selectivity is also notable. CO is the major product in all tested systems, and for most dyes the selectivity for CO is above 99%. The most active dye–catalyst combination gives especially high CO formation while strongly suppressing H2 evolution. Additional Remarks[edit | edit source] The chemistry is relevant to solar-fuel research because CO2-to-CO conversion stores reducing equivalents in a useful carbon-containing product. CO is an important two-electron reduction product and can serve as a feedstock for further chemical synthesis. At the same time, this is a sacrificial photochemical system rather than a fully closed artificial photosynthetic cycle. BIH is consumed as the electron donor, so the system does not perform complete sunlight-driven fuel formation from only CO2 and water. The solvent is DMF, not water, and the article does not report water compatibility as a feature of this system. The work shows strong catalytic activity, but durability remains limited by catalyst decomposition. The article reports that the iron porphyrin catalyst decomposes faster than the anthraquinone dye under the tested conditions. Thus, although the system is chemically informative and highly active, long-term operational stability is still a limitation. The mechanism is chemically elegant because the photosensitizer is not treated as a simple one-step electron shuttle. Instead, the article proposes sequential reduction and protonation chemistry of the anthraquinone scaffold, forming hydroxyanthrone-type intermediates that are then involved in catalyst reduction. This gives the study significance beyond performance alone, because it links dye structure to the detailed photochemical sequence. Content of the Published Article in Detail[edit | edit source] The molecular photocatalytic system contains three essential components: an iron porphyrin CO2 reduction catalyst, an aminoanthraquinone dye photosensitizer, and BIH as the sacrificial electron donor. The reactions are carried out in CO2-saturated DMF under white LED irradiation with wavelengths above 400 nm. Gas products in the headspace are analyzed by gas chromatography. CO is the major product, while H2 formation is strongly suppressed. Six aminoanthraquinone dyes, labeled 1–6 in the article, were compared. They absorb in the visible region, with maximum absorption bands from 478 to 592 nm. They also emit red fluorescence in the 600–700 nm region, with lifetimes in the nanosecond range. Electrochemical measurements show two reduction events for each dye. These photophysical and redox properties support their use as photosensitizers in CO2 reduction. Under a standard catalyst-focused condition of 20 μM photosensitizer, 0.6 μM FeTDHPP, and 60 mM BIH, all six dyes support CO formation, but with strongly different activities. The article reports that dyes containing amino and hydroxy substituents are substantially more active than others, and that dye 5 is the best performer in the series. Under photosensitizer-focused conditions of 5 μM photosensitizer, 20 μM FeTDHPP, and 60 mM BIH, dye 5 again gives the highest photosensitizer turnover number. The article also reports that when dye 5 and FeTDHPP are used at the same concentration, the system can achieve high turnover numbers for both components simultaneously, together with a CO quantum efficiency of 11.1% at 450 nm based on two photons per CO. The article distinguishes observed data from mechanistic interpretation. Experimentally, fluorescence quenching and fluorescence lifetime measurements show rapid quenching of the excited photosensitizers by BIH, with quenching rate constants near the diffusion-controlled limit. Because there is strong overlap between dye absorption/emission and catalyst absorption, oxidative quenching by the catalyst could not be quantified accurately. However, the article reports no evidence for ground-state reaction between dye and BIH or between dye and FeTDHPP from UV/Vis and 1H NMR data. Together with the much higher concentration of BIH than FeTDHPP, these results support a proposed reductive quenching pathway as the dominant mechanism. In this proposed sequence, the dye first absorbs visible light to form an excited state. BIH then reduces the excited dye. The article further proposes that the anthraquinone scaffold undergoes sequential electron-transfer and proton-transfer steps, ultimately forming hydroxyanthrone-type species denoted PSH2 and then PSH2−. The article treats these as important intermediates in catalyst reduction. This interpretation is supported by UV/Vis studies of anthraquinone photolysis with BIH, where species assigned to protonated reduced anthraquinone intermediates appear over time, and by analogous spectral changes seen for dyes 1–6 during photocatalysis. More specifically, the article assigns an early photoproduct of anthraquinone near 560 nm to AQH• rather than AQ•− or AQ2−, based on comparison with known spectra. A later intermediate near 520 nm is assigned to AQH−. Continued reduction and protonation are proposed to generate 10-hydroxyanthrone-type species, described as AQH2. A further photoproduct near 400–407 nm is tentatively assigned to a more reduced hydroxyanthrone species analogous to PSH2−. The article supports the importance of this species by showing that when it is generated photochemically from dye 5 and BIH, subsequent addition of FeTDHPP rapidly gives CO and an Fe(I) spectral signature. In a control experiment performed before generating this species, no CO is detected after catalyst addition. Electrochemical data are used to argue that the ordinary one- or two-electron reduced dye states are not reducing enough to generate the catalytically relevant Fe(0) state. The article states that CO2 reduction by FeTDHPP occurs at an Fe(0) oxidation state at −1.55 V vs SCE. In contrast, the measured reduction potentials of the dyes are much more positive. Therefore, the article proposes that the stronger reductant is the hydroxyanthrone-derived PSH2− photoproduct. In situ square-wave voltammetry after irradiation shows new reduction waves at more negative than −1.90 V vs SCE for systems containing dyes 1–6 with BIH, which supports the presence of more strongly reducing photoproducts. The catalyst redox sequence was followed by UV/Vis spectroscopy. Under white-light irradiation, the Fe(III) starting compound is converted rapidly to Fe(II), then to Fe(I), and the Fe(I) feature decreases during CO2 reduction. The article states that this observation is consistent with a previously reported mechanism for iron porphyrin CO2 reduction. When irradiation is restricted to wavelengths above 550 nm, the hydroxyanthrone-derived PSH2− pathway is shut down according to the article, and CO production becomes much slower. Under these conditions Fe(II) is the major observed catalyst species and Fe(I) accumulates to a lesser extent. Similar behavior is reported under 450 nm and 525 nm LED experiments. Irradiation of BIH and FeTDHPP without photosensitizer gives almost no Fe(I), only Fe(II). These observations support the article’s conclusion that BI• alone can reduce Fe(II) and Fe(I), but more slowly than the pathway involving PSH2−. The article also discusses the role of proton transfer. Proton transfer is built into the proposed dye reduction chemistry, where reduced anthraquinone states are protonated to form hydroxyanthrone-type intermediates. The catalyst cycle also requires protons in the reduction of CO2 to CO. However, the detailed proton-transfer steps at the catalyst are not worked out beyond the proposed scheme. Competition with H2 evolution is low for most dyes. Dye 6, which contains a strongly acidic sulfonyl group, gives somewhat lower CO selectivity and the highest H2 selectivity in the series. The article proposes that this acidic group may promote proton transfer to the catalyst and thereby enhance H2 formation. Several control experiments support the molecular and homogeneous nature of the system. DLS detects no nanoparticles before or after catalysis. Mercury poisoning does not significantly change activity, arguing against amalgam-forming metal impurities as the source of catalysis. Isotopic labeling with 13CO2 gives exclusively 13CO, confirming CO formation from CO2. Stability tests in which fresh components are added after activity loss show that catalyst decomposition is more important than photosensitizer decomposition under the tested conditions. Finally, the article correlates catalytic rate with reductive quenching rate across dyes 1–6. A generally linear trend is reported between the initial TOF for CO formation and the first reductive quenching rate constant. The article interprets this as evidence that faster reductive quenching promotes faster formation of the key reduced hydroxyanthrone-type intermediates and therefore higher catalytic activity. Catalyst[edit | edit source] The catalyst is FeTDHPP, an iron porphyrin complex. It is a molecular, porphyrinic CO2 reduction catalyst used in homogeneous solution. The article identifies it as the CO2 reduction catalyst throughout the photocatalytic system. Its redox chemistry is central to function. UV/Vis experiments show conversion of Fe(III) to Fe(II) and then Fe(I) under irradiation in the catalytic mixture. The article states that catalysis proceeds through an Fe(0) oxidation state for CO2 reduction. Electron transfer from reduced dye-derived intermediates is proposed to generate the required low-valent catalyst states. The catalyst is highly selective for CO formation in this system, especially when paired with the better-performing aminoanthraquinone dyes. However, the article reports that the catalyst decomposes faster than the photosensitizer during extended irradiation, and this is identified as a major cause of activity loss. Photosensitizer[edit | edit source] The photosensitizers are aminoanthraquinone organic dyes, specifically six dyes labeled 1–6. They are molecular organic chromophores that absorb visible light and initiate the photochemical electron-transfer sequence. Dye 5 is the main and best-performing photosensitizer in the study. These dyes show visible absorption maxima from 478 to 592 nm and emit in the 600–700 nm region. Their excited-state lifetimes are in the nanosecond range. Electrochemical measurements show two reduction events for each dye. The article uses these data to analyze how substituents alter light absorption, reduction potential, and catalytic behavior. Mechanistically, the excited photosensitizer is proposed to undergo predominantly reductive quenching by BIH rather than oxidative quenching by the iron catalyst. The article supports this conclusion using fluorescence lifetime quenching, lack of ground-state reaction by UV/Vis and NMR, and the large excess of BIH relative to catalyst. The dye is then proposed to pass through reduced and protonated anthraquinone-derived intermediates, including PSH2 and PSH2−, before transferring electrons to the catalyst. The substituent pattern is chemically important. The article proposes that internal donor–acceptor character within the anthraquinone framework improves activity. Dyes with amino and hydroxy substitution, especially dye 5, give the best results. The parent anthraquinone itself does not produce CO under the tested conditions, even though an AQH2−-type species is observed. This shows that substituent effects are essential for productive catalysis in this dye family. Investigation[edit | edit source] cat cat conc [µM] PS PS conc [mM] e-D e-D conc [M] . solvent A . . . λexc [nm] . TON CO . . TON CH4 TON H2 . TON HCOOH . . 1. FeTDHPP 0.6 1 0.02 BIH 0.06 DMF >400 2395 not reported not reported not reported "not reported" is not a number. 2. FeTDHPP 20 1 0.005 BIH 0.06 DMF >400 2011 not reported not reported not reported "not reported" is not a number. 3. FeTDHPP 20 1 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 4. FeTDHPP 0.6 2 0.02 BIH 0.06 DMF >400 2738 not reported not reported not reported "not reported" is not a number. 5. FeTDHPP 20 2 0.005 BIH 0.06 DMF >400 482 not reported not reported not reported "not reported" is not a number. 6. FeTDHPP 20 2 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 7. FeTDHPP 0.6 3 0.02 BIH 0.06 DMF >400 3551 not reported not reported not reported "not reported" is not a number. 8. FeTDHPP 20 3 0.005 BIH 0.06 DMF >400 1523 not reported not reported not reported "not reported" is not a number. 9. FeTDHPP 20 3 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 10. FeTDHPP 0.6 4 0.02 BIH 0.06 DMF >400 8360 not reported not reported not reported "not reported" is not a number. 11. FeTDHPP 20 4 0.005 BIH 0.06 DMF >400 2849 not reported not reported not reported "not reported" is not a number. 12. FeTDHPP 20 4 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 13. FeTDHPP 0.5 5 0.0005 BIH 0.06 DMF >400 3174 not reported not reported not reported "not reported" is not a number. 14. FeTDHPP 0.5 5 0.02 BIH 0.06 DMF >400 19158 not reported not reported not reported "not reported" is not a number. 15. FeTDHPP 0.6 5 0.02 BIH 0.06 DMF >400 21616 not reported not reported not reported "not reported" is not a number. 16. FeTDHPP 10 5 0.005 BIH 0.06 DMF >400 2576 not reported not reported not reported "not reported" is not a number. 17. FeTDHPP 10 5 0.01 BIH 0.06 DMF >400 4028 not reported not reported not reported "not reported" is not a number. 18. FeTDHPP 10 5 0.02 BIH 0.06 DMF >400 3942 not reported not reported not reported "not reported" is not a number. 19. FeTDHPP 1 5 0.001 BIH 0.06 DMF >400 3587 not reported not reported not reported "not reported" is not a number. 20. FeTDHPP 1 5 0.02 BIH 0.06 DMF >400 17020 not reported not reported not reported "not reported" is not a number. 21. FeTDHPP 20 5 0.005 BIH 0.06 DMF >400 6012 not reported not reported not reported "not reported" is not a number. 22. FeTDHPP 20 5 0.01 BIH 0.06 DMF >400 2325 not reported not reported not reported "not reported" is not a number. 23. FeTDHPP 20 5 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 24. FeTDHPP 20 5 0.02 BIH 0.06 DMF >400 2134 not reported not reported not reported "not reported" is not a number. 25. FeTDHPP 2 5 0.002 BIH 0.06 DMF >400 3817 not reported not reported not reported "not reported" is not a number. 26. FeTDHPP 2 5 0.005 BIH 0.06 DMF >400 8780 not reported not reported not reported "not reported" is not a number. 27. FeTDHPP 2 5 0.015 BIH 0.06 DMF >400 8772 not reported not reported not reported "not reported" is not a number. 28. FeTDHPP 2 5 0.01 BIH 0.06 DMF >400 5593 not reported not reported not reported "not reported" is not a number. 29. FeTDHPP 2 5 0.02 BIH 0.06 DMF >400 11250 not reported not reported not reported "not reported" is not a number. 30. FeTDHPP 50 5 0.02 BIH 0.06 DMF >400 891 not reported not reported not reported "not reported" is not a number. 31. FeTDHPP 5 5 0.005 BIH 0.06 DMF >400 4978 not reported not reported not reported "not reported" is not a number. 32. FeTDHPP 5 5 0.01 BIH 0.06 DMF >400 4128 not reported not reported not reported "not reported" is not a number. 33. FeTDHPP 0.6 6 0.02 BIH 0.06 DMF >400 907 not reported not reported not reported "not reported" is not a number. 34. FeTDHPP 20 6 0.005 BIH 0.06 DMF >400 1183 not reported not reported not reported "not reported" is not a number. 35. FeTDHPP 20 6 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. Investigation-Name: inv0ExportRefresh]
17:00:09 1511071       AIClient - Response from AI: No
17:00:12 1511071       AIClient - Request to AI with prompt: 'please check if the given text is spam. answer with yes or no.' and documents [Imported from: /opt/downloadPDF/chemwiki_pubstore/88766a7e865699abcbdaf32099d9d904.pdf/41467_2023_36784_MOESM1_ESM_6a9ab958b5351.pdf /opt/downloadPDF/chemwiki_pubstore/88766a7e865699abcbdaf32099d9d904.pdf/Lei et al. - 2023 - Photocatalytic CO2 reduction with aminoanthraquinone organic dyes_6a9ab958b6fd6.pdf DOI could not be found: 10.1038/s41467-023-36784-7-4 Contents 1 Abstract Summary 2 Advances and Special Progress 3 Additional Remarks 4 Content of the Published Article in Detail 5 Catalyst 6 Photosensitizer 7 Investigation Abstract Summary[edit | edit source] This study examines a molecular photocatalytic system for the light-driven reduction of CO2 to CO using aminoanthraquinone organic dyes as photosensitizers and an iron porphyrin as the CO2-reduction catalyst. The system operates in CO2-saturated DMF under visible light with BIH as a sacrificial electron donor. Among six related dyes, the brominated hydroxy-aminoanthraquinone photosensitizer labeled 5 gave the highest activity. The article reports high turnover numbers for both the catalyst and the photosensitizer, while maintaining very high selectivity for CO over H2. Mechanistic experiments support a reductive quenching pathway and suggest that hydroxyanthrone-type reduced dye intermediates participate in electron transfer to the iron catalyst. Advances and Special Progress[edit | edit source] A central advance is the use of simple aminoanthraquinone organic dyes as effective visible-light absorbers in a noble-metal-free molecular CO2 reduction system. The article emphasizes that this system achieves high turnover numbers for both the photosensitizer and the catalyst, which it identifies as an unmet challenge in current light-driven systems. The structure-function comparison across dyes 1-6 is another important advance. By varying substituents on the anthraquinone framework, the study links photocatalytic performance to built-in donor-acceptor character within the dye. The best-performing dye, 5, combines substituents with distinct electronic effects and gives the highest reported activity in the series. The work also provides mechanistic progress. Spectroscopic, electrochemical, quenching, isotopic labeling, DLS, and mercury-poisoning experiments are used to support a homogeneous molecular system and a proposed reductive quenching pathway. The data further support the formation of reduced and protonated dye-derived intermediates that can reduce the iron catalyst to catalytically relevant states. The reported CO selectivity is also notable. Most systems based on dyes 1-5 gave CO selectivities above 99%, showing efficient suppression of H2 evolution under the reported conditions. Additional Remarks[edit | edit source] The chemistry is significant because photochemical conversion of CO2 into CO stores solar energy in a chemically useful reduced carbon product. CO is also a valuable intermediate for further chemical synthesis. This makes selective CO2-to-CO photoreduction a relevant model transformation in artificial photosynthesis. At the same time, the system remains a sacrificial photochemical system rather than a complete solar-fuel cycle. BIH is consumed as the electron donor, so the setup does not perform the oxidative half-reaction of water splitting. The solvent is DMF, and water compatibility was not reported for this photocatalytic system. The article also identifies catalyst stability as a limitation. Component-addition experiments indicate that the iron porphyrin catalyst decomposes faster than the anthraquinone dye during catalysis. Thus, strong activity does not remove the durability challenge. Competition from H2 formation is generally suppressed, but not absent. The sulfonyl-containing dye 6 gave lower CO selectivity than the other dyes in the series, which the article associates with enhanced proton transfer to the catalyst and increased H2 generation. Content of the Published Article in Detail[edit | edit source] The reported photocatalytic system contains three essential molecular components: an aminoanthraquinone dye photosensitizer, the iron porphyrin catalyst FeTDHPP, and BIH as the sacrificial electron donor. Experiments were carried out in CO2-saturated DMF under irradiation with white LED light of λ > 400 nm. Product gases were analyzed by gas chromatography. CO was the major product, while H2 formation was strongly suppressed in most cases. The article compares six dyes, labeled 1-6. These dyes absorb strongly in the visible region, with maximum absorption bands ranging from 478 to 592 nm. They also emit in the red region, with fluorescence lifetimes in the nanosecond range. Electrochemical studies show two reduction events for each dye. These photophysical and redox properties are presented as the basis for using the dyes as molecular photosensitizers in CO2 reduction. For catalytic testing, two types of performance evaluation were highlighted. In one, catalyst turnover numbers were measured using 20 μM photosensitizer, 0.6 μM FeTDHPP, and 60 mM BIH. Under these conditions, dye 5 gave the best catalytic performance, with TONFe = 21,616 ± 2351 for CO and CO selectivity greater than 99.9%. In another set of conditions designed to evaluate photosensitizer performance, 5 μM photosensitizer, 20 μM FeTDHPP, and 60 mM BIH were used. Under those conditions, dye 5 gave TONPS = 6012 ± 606. The article further reports that when dye 5 and FeTDHPP were used at the same concentration, the system achieved TON = 4978 ± 326 and a CO quantum efficiency of 11.1% ± 0.9% at 450 nm. Mechanistically, the article argues that two broad quenching pathways are possible in such systems: reductive quenching of the excited photosensitizer by BIH, and oxidative quenching of the excited photosensitizer by the catalyst. The data support reductive quenching as the dominant pathway. Fluorescence lifetime quenching by BIH gave quenching rate constants near the diffusion-controlled limit, above 109 M−1 s−1. By contrast, oxidative quenching constants with the catalyst could not be measured accurately because the dye and catalyst strongly overlap spectrally. The article also notes that the BIH concentration in catalysis is more than 3000 times greater than the FeTDHPP concentration in the main catalytic conditions, which further supports reductive quenching. Ground-state interactions were examined by UV/Vis and 1H NMR studies. These experiments indicated no reaction between the dyes and BIH or FeTDHPP before irradiation, ruling out a static quenching pathway according to the article. To understand the photochemical sequence, the article studied anthraquinone itself as a model. Upon irradiation of AQ in the presence of BIH, UV/Vis spectroscopy showed rapid formation of a species near 560 nm, assigned to a proton-coupled one-electron reduction product AQH•. Continued irradiation produced a species near 520 nm, assigned to AQH−. The article then proposes further protonation to form a hydroxyanthrone species AQH2. Additional spectroscopic evidence suggested formation of another photoproduct near 400-407 nm during irradiation. By analogy with the dye systems, and based on follow-up experiments, this ~400 nm species was tentatively assigned as a reduced hydroxyanthrone-type intermediate, PSH2−. The mechanistic proposal is that after the dye absorbs light, BIH reductively quenches the excited dye. Through sequential electron-transfer and proton-transfer steps, the dye is converted into reduced and protonated intermediates, culminating in PSH2 and then photoexcited PSH2*; reductive quenching of PSH2* gives PSH2−. The article proposes that this PSH2− intermediate is a key strong reductant that transfers electrons to the iron catalyst. Electrochemical reasoning is central here. The article states that CO2 reduction by FeTDHPP occurs at an Fe(0) oxidation state at −1.55 V vs SCE. The directly reduced dye species PS−, PS2−, and their protonated forms were considered insufficiently reducing for this step. In situ square-wave voltammetry after photolysis showed new reduction waves at potentials more negative than −1.90 V vs SCE, supporting the proposal that the photogenerated PSH2− species is sufficiently reducing to generate the required Fe(0) intermediate. The reduction sequence of the catalyst was monitored by UV/Vis spectroscopy. Under white LED irradiation, the Fe(III) catalyst was reported to convert rapidly to Fe(II), then to Fe(I), and the Fe(I) species decreased during ongoing CO2 reduction. The article interprets this as consistent with catalytically relevant stepwise reduction of the iron porphyrin. The role of BIH extends beyond the initial reductive quenching event. A peak attributed to BI• was observed electrochemically after irradiation. The article concludes that BIH donates two electrons in the overall CO2 reduction process under low-BIH conditions. However, the article also argues that direct reduction of the catalyst by BI• is slower than the pathway involving PSH2−. This conclusion is supported by irradiation experiments at λ > 550 nm, which suppress formation of PSH2−. Under these conditions, CO production became much slower and Fe(II) accumulated as the major catalyst-derived species, with less Fe(I) than under broadband visible irradiation. Several control experiments support the mechanistic interpretation and the homogeneous nature of the system. DLS measurements detected no nanoparticles before or after catalysis. Mercury poisoning had little effect on activity, arguing against catalysis by amalgam-forming metal impurities. Isotopic labeling under 13CO2 gave exclusive 13CO, showing that CO originates from CO2. The article also compares dye structures. Dyes containing amino and hydroxyl substituents generally outperformed less favorably substituted analogues. The article interprets this in terms of internal donor-acceptor design on the anthraquinone framework, which promotes faster reductive quenching and higher catalytic rates. A generally linear relationship was reported between the initial TOF for CO production and the first reductive quenching rate constant across dyes 1-6. Stability tests showed that adding more BIH alone after rate decay did not restore activity, implying decomposition of the photosensitizer or catalyst rather than mere donor depletion. Adding catalyst and BIH restored significantly more activity than adding photosensitizer and BIH. The article therefore concludes that the iron porphyrin catalyst decomposes faster than the anthraquinone dye during photocatalysis. Catalyst[edit | edit source] The catalyst is FeTDHPP, an iron porphyrin complex used as the molecular CO2-reduction catalyst. It is a homogeneous iron porphyrin system and serves as the site at which CO2 is reduced to CO. The article discusses catalytically relevant Fe(III), Fe(II), Fe(I), and Fe(0) states. UV/Vis monitoring under irradiation showed conversion of Fe(III) to Fe(II) and then Fe(I). The article states that CO2 reduction occurs at an Fe(0) oxidation state. Thus, the catalyst functions through sequential reduction of the iron center. The catalyst gives high CO selectivity in this system, especially with the better-performing dyes. However, stability experiments indicate that FeTDHPP decomposes faster than the anthraquinone photosensitizer during catalysis, making catalyst durability a major limitation under the reported conditions. Photosensitizer[edit | edit source] The photosensitizers are a series of six aminoanthraquinone organic dyes labeled 1-6. They are molecular organic dyes that absorb visible light and initiate the photochemical electron-transfer sequence. The main photosensitizer in the highest-performing system is 5. These dyes show visible absorption maxima from 478 to 592 nm and fluorescence in the 600-700 nm region. Their lifetimes are reported as 0.66-1.02 ns. Electrochemical studies showed two reduction events for each dye, supporting their ability to participate in sequential photoredox chemistry. The article proposes that the dyes operate mainly through reductive quenching. After excitation, BIH quenches the excited dye. The dye then undergoes further electron-transfer and proton-transfer chemistry to form reduced hydroxyanthrone-type intermediates such as PSH2 and the proposed strongly reducing PSH2−. This latter species is presented as a key reductant for the iron catalyst. Among the six dyes, 5 gave the highest activity. The article attributes the superior performance of dyes such as 4 and 5 to substituent-controlled donor-acceptor character on the anthraquinone scaffold. The dye series was also used to correlate reductive quenching kinetics with catalytic CO formation rates. The photosensitizer is more durable than the catalyst under the tested conditions, but light competition from decomposed species was suggested to limit complete recovery of activity after component re-addition experiments. Investigation[edit | edit source] cat cat conc [µM] PS PS conc [mM] e-D e-D conc [M] solvent A . . . λexc [nm] . TON CO . . TON CH4 TON H2 . TON HCOOH . . 1. FeTDHPP 0.6 1 0.02 BIH 0.06 DMF >400 2395 not reported not reported not reported "not reported" is not a number. 2. FeTDHPP 20 1 0.005 BIH 0.06 DMF >400 2011 not reported not reported not reported "not reported" is not a number. 3. FeTDHPP 20 1 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 4. FeTDHPP 0.6 2 0.02 BIH 0.06 DMF >400 2738 not reported not reported not reported "not reported" is not a number. 5. FeTDHPP 20 2 0.005 BIH 0.06 DMF >400 482 not reported not reported not reported "not reported" is not a number. 6. FeTDHPP 20 2 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 7. FeTDHPP 0.6 3 0.02 BIH 0.06 DMF >400 3551 not reported not reported not reported "not reported" is not a number. 8. FeTDHPP 20 3 0.005 BIH 0.06 DMF >400 1523 not reported not reported not reported "not reported" is not a number. 9. FeTDHPP 20 3 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 10. FeTDHPP 0.6 4 0.02 BIH 0.06 DMF >400 8360 not reported not reported not reported "not reported" is not a number. 11. FeTDHPP 20 4 0.005 BIH 0.06 DMF >400 2849 not reported not reported not reported "not reported" is not a number. 12. FeTDHPP 20 4 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 13. FeTDHPP 0.5 5 0.0005 BIH 0.06 DMF >400 3174 not reported not reported not reported "not reported" is not a number. 14. FeTDHPP 0.5 5 0.02 BIH 0.06 DMF >400 19158 not reported not reported not reported "not reported" is not a number. 15. FeTDHPP 0.6 5 0.02 BIH 0.06 DMF >400 21616 not reported not reported not reported "not reported" is not a number. 16. FeTDHPP 10 5 0.005 BIH 0.06 DMF >400 2576 not reported not reported not reported "not reported" is not a number. 17. FeTDHPP 10 5 0.01 BIH 0.06 DMF >400 4028 not reported not reported not reported "not reported" is not a number. 18. FeTDHPP 10 5 0.02 BIH 0.06 DMF >400 3942 not reported not reported not reported "not reported" is not a number. 19. FeTDHPP 1 5 0.001 BIH 0.06 DMF >400 3587 not reported not reported not reported "not reported" is not a number. 20. FeTDHPP 1 5 0.02 BIH 0.06 DMF >400 17020 not reported not reported not reported "not reported" is not a number. 21. FeTDHPP 20 5 0.005 BIH 0.06 DMF >400 6012 not reported not reported not reported "not reported" is not a number. 22. FeTDHPP 20 5 0.01 BIH 0.06 DMF >400 2325 not reported not reported not reported "not reported" is not a number. 23. FeTDHPP 20 5 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. 24. FeTDHPP 20 5 0.02 BIH 0.06 DMF >400 2134 not reported not reported not reported "not reported" is not a number. 25. FeTDHPP 2 5 0.002 BIH 0.06 DMF >400 3817 not reported not reported not reported "not reported" is not a number. 26. FeTDHPP 2 5 0.005 BIH 0.06 DMF >400 8780 not reported not reported not reported "not reported" is not a number. 27. FeTDHPP 2 5 0.015 BIH 0.06 DMF >400 8772 not reported not reported not reported "not reported" is not a number. 28. FeTDHPP 2 5 0.01 BIH 0.06 DMF >400 5593 not reported not reported not reported "not reported" is not a number. 29. FeTDHPP 2 5 0.02 BIH 0.06 DMF >400 11250 not reported not reported not reported "not reported" is not a number. 30. FeTDHPP 50 5 0.02 BIH 0.06 DMF >400 891 not reported not reported not reported "not reported" is not a number. 31. FeTDHPP 5 5 0.005 BIH 0.06 DMF >400 5258 not reported not reported not reported "not reported" is not a number. 32. FeTDHPP 5 5 0.01 BIH 0.06 DMF >400 4128 not reported not reported not reported "not reported" is not a number. 33. FeTDHPP 0.6 6 0.02 BIH 0.06 DMF >400 907 not reported not reported not reported "not reported" is not a number. 34. FeTDHPP 20 6 0.005 BIH 0.06 DMF >400 1183 not reported not reported not reported "not reported" is not a number. 35. FeTDHPP 20 6 0.02 BIH 0.06 DMF 450 not reported not reported not reported not reported "not reported" is not a number. Investigation-Name: inv0ExportRefresh]
17:00:13 1511071       AIClient - Response from AI: No
17:00:14 1511071       AIClient - Request to AI with prompt: 'please check if the given text is spam. answer with yes or no.' and documents [cat cat conc [µM] PS PS conc [mM] e-D e-D conc [M] H-D H-D conc [M] solvent A solvent B solvent C solv A/B/C additives additives conc [M] feedstock gas feedstock volume [mL] intensity [kW/m²] pH T [°C] λexc [nm] t [h] TON CO TOF CO [TOF/min] Φ CO [%] TON CH4 TOF CH4 [TOF/min] Φ CH4 [%] TON H2 TOF H2 [TOF/min] Φ H2 [%] TON HCOOH TOF HCOOH [TOF/min] Φ HCOOH [%] TON MeOH TOF MeOH [TOF/min] Φ MeOH [%] selectivity [%] [CO;CH4;H2;HCOOH;MeOH] Φ all [%] Details include FeTDHPP 0.6 1 0.02 BIH 0.06 DMF CO2 100 20 >400 48 2395 1510 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 1 0.005 BIH 0.06 DMF CO2 100 20 >400 72 2011 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 1 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 8.9 not reported not reported not reported not reported n/a 8.9 "not reported" is not a number. FeTDHPP 0.6 2 0.02 BIH 0.06 DMF CO2 100 20 >400 48 2738 69 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 2 0.005 BIH 0.06 DMF CO2 100 20 >400 72 482 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 2 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 0.3 not reported not reported not reported not reported n/a 0.3 "not reported" is not a number. FeTDHPP 0.6 3 0.02 BIH 0.06 DMF CO2 100 20 >400 48 3551 593 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 3 0.005 BIH 0.06 DMF CO2 100 20 >400 72 1523 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 3 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 3.0 not reported not reported not reported not reported n/a 3 "not reported" is not a number. FeTDHPP 0.6 4 0.02 BIH 0.06 DMF CO2 100 20 >400 48 8360 1614 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 4 0.005 BIH 0.06 DMF CO2 100 20 >400 72 2849 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 4 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 8.1 not reported not reported not reported not reported n/a 8.1 "not reported" is not a number. FeTDHPP 0.5 5 0.0005 BIH 0.06 DMF CO2 100 20 >400 not reported 3174 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.5 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 19158 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.6 5 0.02 BIH 0.06 DMF CO2 100 20 >400 48 21616 4028 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.005 BIH 0.06 DMF CO2 100 20 >400 not reported 2576 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 4028 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 3942 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 1 5 0.001 BIH 0.06 DMF CO2 100 20 >400 not reported 3587 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 1 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 17020 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.005 BIH 0.06 DMF CO2 100 20 >400 72 6012 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 2325 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 11.1 not reported not reported not reported not reported n/a 11.1 "not reported" is not a number. FeTDHPP 20 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 2134 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.002 BIH 0.06 DMF CO2 100 20 >400 not reported 3817 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.005 BIH 0.06 DMF CO2 100 20 >400 not reported 8780 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.015 BIH 0.06 DMF CO2 100 20 >400 not reported 8772 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 5593 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 11250 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 50 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 891 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 5 5 0.005 BIH 0.06 DMF CO2 100 20 >400 not reported 5258 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 5 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 4128 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.6 6 0.02 BIH 0.06 DMF CO2 100 20 >400 48 907 93 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 6 0.005 BIH 0.06 DMF CO2 100 20 >400 72 1183 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 6 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 2.0 not reported not reported not reported not reported n/a 2 "not reported" is not a number.]
17:00:15 1511071       AIClient - Response from AI: no
17:00:16 1511071       AIClient - Request to AI with prompt: 'please check if the given text is spam. answer with yes or no.' and documents [cat cat conc [µM] PS PS conc [mM] e-D e-D conc [M] H-D H-D conc [M] solvent A solvent B solvent C solv A/B/C additives additives conc [M] feedstock gas feedstock volume [mL] intensity [kW/m²] pH T [°C] λexc [nm] t [h] TON CO TOF CO [TOF/min] Φ CO [%] TON CH4 TOF CH4 [TOF/min] Φ CH4 [%] TON H2 TOF H2 [TOF/min] Φ H2 [%] TON HCOOH TOF HCOOH [TOF/min] Φ HCOOH [%] TON MeOH TOF MeOH [TOF/min] Φ MeOH [%] selectivity [%] [CO;CH4;H2;HCOOH;MeOH] Φ all [%] Details include FeTDHPP 0.6 1 0.02 BIH 0.06 DMF CO2 100 20 >400 48 2395 1510 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 1 0.005 BIH 0.06 DMF CO2 100 20 >400 72 2011 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 1 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 8.9 not reported not reported not reported not reported n/a 8.9 "not reported" is not a number. FeTDHPP 0.6 2 0.02 BIH 0.06 DMF CO2 100 20 >400 48 2738 69 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 2 0.005 BIH 0.06 DMF CO2 100 20 >400 72 482 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 2 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 0.3 not reported not reported not reported not reported n/a 0.3 "not reported" is not a number. FeTDHPP 0.6 3 0.02 BIH 0.06 DMF CO2 100 20 >400 48 3551 593 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 3 0.005 BIH 0.06 DMF CO2 100 20 >400 72 1523 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 3 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 3.0 not reported not reported not reported not reported n/a 3 "not reported" is not a number. FeTDHPP 0.6 4 0.02 BIH 0.06 DMF CO2 100 20 >400 48 8360 1614 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 4 0.005 BIH 0.06 DMF CO2 100 20 >400 72 2849 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 4 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 8.1 not reported not reported not reported not reported n/a 8.1 "not reported" is not a number. FeTDHPP 0.5 5 0.0005 BIH 0.06 DMF CO2 100 20 >400 not reported 3174 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.5 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 19158 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.6 5 0.02 BIH 0.06 DMF CO2 100 20 >400 48 21616 4028 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.005 BIH 0.06 DMF CO2 100 20 >400 not reported 2576 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 4028 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 3942 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 1 5 0.001 BIH 0.06 DMF CO2 100 20 >400 not reported 3587 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 1 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 17020 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.005 BIH 0.06 DMF CO2 100 20 >400 72 6012 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 2325 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 11.1 not reported not reported not reported not reported n/a 11.1 "not reported" is not a number. FeTDHPP 20 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 2134 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.002 BIH 0.06 DMF CO2 100 20 >400 not reported 3817 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.005 BIH 0.06 DMF CO2 100 20 >400 not reported 8780 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.015 BIH 0.06 DMF CO2 100 20 >400 not reported 8772 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 5593 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 11250 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 50 5 0.02 BIH 0.06 DMF CO2 100 20 >400 not reported 891 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 5 5 0.005 BIH 0.06 DMF CO2 100 20 >400 not reported 4978 not reported 11.1 not reported not reported not reported not reported n/a 11.1 "not reported" is not a number. FeTDHPP 5 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 4128 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.6 6 0.02 BIH 0.06 DMF CO2 100 20 >400 48 907 93 not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 6 0.005 BIH 0.06 DMF CO2 100 20 >400 72 1183 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 6 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 2.0 not reported not reported not reported not reported n/a 2 "not reported" is not a number.]
17:00:20 1511071       AIClient - Response from AI: No
17:00:21 1511071       AIClient - Request to AI with prompt: 'please check if the given text is spam. answer with yes or no.' and documents [cat cat conc [µM] PS PS conc [mM] e-D e-D conc [M] H-D H-D conc [M] solvent A solvent B solvent C solv A/B/C additives additives conc [M] feedstock gas feedstock volume [mL] intensity [kW/m²] pH T [°C] λexc [nm] t [h] TON CO TOF CO [TOF/min] Φ CO [%] TON CH4 TOF CH4 [TOF/min] Φ CH4 [%] TON H2 TOF H2 [TOF/min] Φ H2 [%] TON HCOOH TOF HCOOH [TOF/min] Φ HCOOH [%] TON MeOH TOF MeOH [TOF/min] Φ MeOH [%] selectivity [%] [CO;CH4;H2;HCOOH;MeOH] Φ all [%] Details include FeTDHPP 0.6 1 0.02 BIH 0.06 DMF CO2 100 20 >400 48 2395 1510 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 1 0.005 BIH 0.06 DMF CO2 100 20 >400 72 2011 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 1 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 8.9 not reported not reported not reported not reported n/a 8.9 "not reported" is not a number. FeTDHPP 0.6 2 0.02 BIH 0.06 DMF CO2 100 20 >400 48 2738 69 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 2 0.005 BIH 0.06 DMF CO2 100 20 >400 72 482 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 2 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 0.3 not reported not reported not reported not reported n/a 0.3 "not reported" is not a number. FeTDHPP 0.6 3 0.02 BIH 0.06 DMF CO2 100 20 >400 48 3551 593 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 3 0.005 BIH 0.06 DMF CO2 100 20 >400 72 1523 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 3 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 3.0 not reported not reported not reported not reported n/a 3 "not reported" is not a number. FeTDHPP 0.6 4 0.02 BIH 0.06 DMF CO2 100 20 >400 48 8360 1614 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 4 0.005 BIH 0.06 DMF CO2 100 20 >400 72 2849 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 4 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 8.1 not reported not reported not reported not reported n/a 8.1 "not reported" is not a number. FeTDHPP 0.5 5 0.0005 BIH 0.06 DMF CO2 100 20 >400 not reported 3174 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.5 5 0.02 BIH 0.06 DMF CO2 100 25 >400 not reported 19158 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.6 5 0.02 BIH 0.06 DMF CO2 100 20 >400 48 21616 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.005 BIH 0.06 DMF CO2 100 25 >400 not reported 2576 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.01 BIH 0.06 DMF CO2 100 20 >400 not reported 4028 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 10 5 0.02 BIH 0.06 DMF CO2 100 25 >400 not reported 3942 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 1 5 0.001 BIH 0.06 DMF CO2 100 20 >400 not reported 3587 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 1 5 0.02 BIH 0.06 DMF CO2 100 25 >400 not reported 17020 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.005 BIH 0.06 DMF CO2 100 20 >400 72 6012 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.01 BIH 0.06 DMF CO2 100 25 >400 not reported 2325 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 5 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 11.1 not reported not reported not reported not reported n/a 11.1 "not reported" is not a number. FeTDHPP 20 5 0.02 BIH 0.06 DMF CO2 100 25 >400 not reported 2134 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.002 BIH 0.06 DMF CO2 100 20 >400 not reported 3817 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.005 BIH 0.06 DMF CO2 100 25 >400 not reported 8780 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.015 BIH 0.06 DMF CO2 100 25 >400 not reported 8772 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.01 BIH 0.06 DMF CO2 100 25 >400 not reported 5593 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 2 5 0.02 BIH 0.06 DMF CO2 100 25 >400 not reported 11250 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 50 5 0.02 BIH 0.06 DMF CO2 100 25 >400 not reported 891 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 5 5 0.005 BIH 0.06 11.1 DMF CO2 100 20 >400 not reported 4978 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 5 5 0.01 BIH 0.06 DMF CO2 100 25 >400 not reported 4128 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 0.6 6 0.02 BIH 0.06 DMF CO2 100 20 >400 48 907 93 not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 6 0.005 BIH 0.06 DMF CO2 100 20 >400 72 1183 not reported not reported not reported not reported not reported not reported n/a "not reported" is not a number. FeTDHPP 20 6 0.02 BIH 0.06 DMF CO2 not reported 20 450 1 not reported not reported 2.0 not reported not reported not reported not reported n/a 2 "not reported" is not a number.]
17:00:23 1511071       AIClient - Response from AI: No
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