Metal-free reduction of CO2 to formate using a photochemical organohydride-catalyst recycling strategy: Difference between revisions
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===Content of the published article in detail=== | ===Content of the published article in detail=== | ||
The article contains results for the reduction of CO<sub>2</sub> to HCOO<sup>-</sup> under visible-light catalysis using {{#moleculelink:|link=RDSICPYJALLFAN-UHFFFAOYSA-M|image=false|width=300|height=200}} as a catalyst. The catalytic system performs best (referring to the TON of formic acid production) in MeCN/H<sub>2</sub>O with photosensitizer {{#moleculelink:|link=SEAGXMGVRJVEBS-UHFFFAOYSA-N|image=false|width=300|height=200}}. | The article contains results for the reduction of CO<sub>2</sub> to HCOO<sup>-</sup> under visible-light catalysis using {{#moleculelink:|link=RDSICPYJALLFAN-UHFFFAOYSA-M|image=false|width=300|height=200}} as a catalyst. The catalytic system performs best (referring to the TON of formic acid production for the catalyst) in MeCN/H<sub>2</sub>O with photosensitizer {{#moleculelink:|link=SEAGXMGVRJVEBS-UHFFFAOYSA-N|image=false|width=300|height=200}}. | ||
====Catalyst==== | ====Catalyst==== | ||
<chemform smiles="C1C=CC2N(C)C(C)=[N+](C)C=2C=1.[I-]" inchi="1S/C10H13N2.HI/c1-8-11(2)9-6-4-5-7-10(9)12(8)3;/h4-7H,1-3H3;1H/q+1;/p-1" inchikey="RDSICPYJALLFAN-UHFFFAOYSA-M" height="200px" width="300px" float="none"> | <chemform smiles="C1C=CC2N(C)C(C)=[N+](C)C=2C=1.[I-]" inchi="1S/C10H13N2.HI/c1-8-11(2)9-6-4-5-7-10(9)12(8)3;/h4-7H,1-3H3;1H/q+1;/p-1" inchikey="RDSICPYJALLFAN-UHFFFAOYSA-M" height="200px" width="300px" float="none"> | ||
Latest revision as of 12:49, 17 May 2024
Abstract[edit | edit source]
Summary[edit | edit source]
A photochemical reduction of CO2 to formic acid was shown using 1,2,3-Trimethylbenzimidazolium iodide as catalyst in combination with the organic carbazole-based photosensitizer 3,6-bis(dimethylamino)-9-phenyl-9H-carbazole. Turnover numbers (TONs) of 6080 for the catalyst and 8820 for the photosensitizer and an exclusive selectivity for formic acid were reached in MeCN/H2O. The experiments were conducted under visible-light irradiation (λ = 400 nm) using ascorbic acid as sacrificial electron donor (see section SEDs below) and potassium carbonate as a base.
Advances and special progress[edit | edit source]
A transition-metal free process for the efficient photocatalytic reduction of CO2 to formic acid was described. The use of an organohydride catalyst allowed for a high selectivity for formate without noteworthy formation of H2 or CO.
Additional remarks[edit | edit source]
Derivatives in which the carbazole and benzimidazolium moieties were covalently connected were tested as a combined catalyst/photosensitizer, but showed a lower activity in catalyzing CO2 reduction.
Content of the published article in detail[edit | edit source]
The article contains results for the reduction of CO2 to HCOO- under visible-light catalysis using 1,2,3-Trimethylbenzimidazolium iodide as a catalyst. The catalytic system performs best (referring to the TON of formic acid production for the catalyst) in MeCN/H2O with photosensitizer 3,6-bis(dimethylamino)-9-phenyl-9H-carbazole.
Catalyst[edit | edit source]
1,2,3-Trimethylbenzimidazolium iodide
BIH
Photosensitizer[edit | edit source]
3,6-bis(dimethylamino)-9-phenyl-9H-carbazole
3,6-bis(dimethylamino)carbazole
3,6-Bis(diphenylamino)-9-phenyl-9H-carbazole
Ir(ppy)3
Investigation[edit | edit source]
| cat | cat conc [µM] | PS | PS conc [mM] | e-D | e-D conc [M] | solvent A | . | . | . | λexc [nm] | . | TON CO | . | . | . | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | 2.5 | 0.005 | 0.05 | 400 | 2750 | |||||||||||
| 2. | 2.5 | 0.005 | 0.05 | 400 | 6510 | |||||||||||
| 3. | 2.5 | 0.005 | 0.05 | 400 | 8820 | |||||||||||
| 4. | 2.5 | 0.005 | 0.05 | 400 | 7380 | |||||||||||
| 5. | 2.5 | 0.05 | 400 | 0 | ||||||||||||
| 6. | 0.05 | 0.5 | 0.05 | 400 | 61 | |||||||||||
| 7. | 0.5 | 0.05 | 400 | 0 | ||||||||||||
| 8. | 0.05 | 0.05 | 0.05 | 400 | 710 | |||||||||||
| 9. | 0.05 | 0.005 | 0.05 | 400 | 860 | |||||||||||
| 10. | 0.005 | 0.005 | 0.05 | 400 | 0 |
Sacrificial electron donor[edit | edit source]
In this study, the experiments were done with the sacrificial electron donor ascorbic acid L-ascorbate, sodium. The use of BIH was tested, but found to yield worse results.
Additives[edit | edit source]
In this study, potassium carbonate was added as a base. Control experiments under argon and with other bases were performed.
Investigations
- photocatalytic CO2 conversion under different conditions (Molecular process, Photocatalytic CO2 conversion experiments)
