Editing Toward Visible-Light Photochemical CO2‑to-CH4 Conversion in Aqueous Solutions Using Sensitized Molecular Catalysis

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{{DOI|doi=10.1021/acs.jpcc.8b00950}}
=== Abstract ===

==== Summary====
A photochemical reduction of CO<sub>2</sub> was achieved using an iron porphyrin catalyst {{#moleculelink:|link=LKNRTBVZMCBYCY-NGWNFTKISA-I|image=false|width=300|height=200}} and an iridium complex as the photosensitizer ({{#moleculelink:|link=RJJGJTKSOSSNNL-UHFFFAOYSA-N|image=false|width=300|height=200}} or {{#moleculelink:|link=NSABRUJKERBGOU-UHFFFAOYSA-N|image=false|width=300|height=200}}). Carbon monoxide, produced with a TON of 178 under optimized conditions, was the main product, methane was produced in a substantial amount with the TON of 32, while hydrogen was formed as a minor byproduct. The experiments were performed under irradiation with ''λ >'' 420 nm in acetonitrile and in the presence of various amines as sacrificial electron donors.

==== Advances and special progress====
The catalytic reduction of CO<sub>2</sub> could also be realized under aqueous conditions (acetonitrile/water 3:7 v:v), yielding carbon monoxide as the main product while methane was produced with selectivity up to 10% (TON of 3).

==== Additional remarks====
Among the various amines employed as sacrificial electron donors, TEA appeared as the best choice to maximize CO<sub>2</sub> product formation.

=== Content of the published article in detail ===
The article contains results for the reduction of CO<sub>2</sub> to CO as the main product under visible-light irradiation using iron porphyrin complex Fe(pTMAPP)Cl<sub>5</sub> ({{#moleculelink:|link=LKNRTBVZMCBYCY-NGWNFTKISA-I|image=false|width=300|height=200}}) as the catalysts, an iridium complex as the photosensitizer and various amines as the sacrificial electron donor. The catalytic system performs best (referring to the TON of CO production) with Ir(ppy)<sub>3</sub> ({{#moleculelink: |link=NSABRUJKERBGOU-UHFFFAOYSA-N|image=false|width=300|height=200}}) as the photosensitizer and TEA as the sacrificial electron donor.

==== Catalyst====
{{#moleculelink:|link=LKNRTBVZMCBYCY-NGWNFTKISA-I|image=true|width=300|height=200}}

====Photosensitizer====
<chemform smiles="C1C=C[C-]2[Ir+3]3([C-]4C=CC=CC=4C4C=CC=CN=43)3(N4=CC=CC=C4C4C=CC=CN=43)N3=CC=CC=C3C=2C=1.[P-](F)(F)(F)(F)(F)F" inchi="1S/2C11H8N.C10H8N2.F6P.Ir/c2*1-2-6-10(7-3-1)11-8-4-5-9-12-11;1-3-7-11-9(5-1)10-6-2-4-8-12-10;1-7(2,3,4,5)6;/h2*1-6,8-9H;1-8H;;/q2*-1;;-1;+3" inchikey="RJJGJTKSOSSNNL-UHFFFAOYSA-N" height="200px" width="300px" float="none">
  -INDIGO-08012317332D

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M  V30 BEGIN CTAB
M  V30 COUNTS 44 51 0 0 0
M  V30 BEGIN ATOM
M  V30 1 C 4.03485 -3.90007 0.0 0
M  V30 2 C 5.76515 -3.89959 0.0 0
M  V30 3 C 4.90164 -3.39997 0.0 0
M  V30 4 C 5.76515 -4.90053 0.0 0 CHG=-1
M  V30 5 C 4.03485 -4.90502 0.0 0
M  V30 6 C 4.90382 -5.40003 0.0 0
M  V30 7 C 6.63141 -3.39999 0.0 0
M  V30 8 C 7.49583 -1.90109 0.0 0
M  V30 9 C 6.63149 -2.39928 0.0 0
M  V30 10 C 8.36278 -2.40138 0.0 0
M  V30 11 N 7.50182 -3.90229 0.0 0
M  V30 12 C 8.3649 -3.39706 0.0 0
M  V30 13 C 4.08485 -6.82507 0.0 0
M  V30 14 C 5.81515 -6.82459 0.0 0 CHG=-1
M  V30 15 C 4.95164 -6.32497 0.0 0
M  V30 16 C 5.81515 -7.82553 0.0 0
M  V30 17 C 4.08485 -7.83002 0.0 0
M  V30 18 C 4.95382 -8.32503 0.0 0
M  V30 19 C 6.68166 -8.3247 0.0 0
M  V30 20 C 8.41196 -8.32139 0.0 0
M  V30 21 N 7.54763 -7.82318 0.0 0
M  V30 22 C 8.41359 -9.32233 0.0 0
M  V30 23 C 6.6833 -9.32964 0.0 0
M  V30 24 C 7.55308 -9.82324 0.0 0
M  V30 25 C 9.35985 -3.77507 0.0 0
M  V30 26 C 11.0902 -3.77459 0.0 0
M  V30 27 C 10.2266 -3.27497 0.0 0
M  V30 28 C 11.0902 -4.77553 0.0 0
M  V30 29 N 9.35985 -4.78002 0.0 0
M  V30 30 C 10.2288 -5.27503 0.0 0
M  V30 31 C 10.2327 -6.27503 0.0 0
M  V30 32 C 11.105 -7.76933 0.0 0
M  V30 33 C 11.1014 -6.7717 0.0 0
M  V30 34 C 10.2405 -8.27372 0.0 0
M  V30 35 N 9.36465 -6.78143 0.0 0
M  V30 36 C 9.37498 -7.78146 0.0 0
M  V30 37 Ir 7.55 -5.775 0.0 0 CHG=3
M  V30 38 P 13.517 -3.7 0.0 0 CHG=-1
M  V30 39 F 14.383 -3.2 0.0 0
M  V30 40 F 12.651 -3.2 0.0 0
M  V30 41 F 13.517 -4.7 0.0 0
M  V30 42 F 14.383 -4.2 0.0 0
M  V30 43 F 13.517 -2.7 0.0 0
M  V30 44 F 12.651 -4.2 0.0 0
M  V30 END ATOM
M  V30 BEGIN BOND
M  V30 1 2 3 1
M  V30 2 2 4 2
M  V30 3 1 1 5
M  V30 4 1 2 3
M  V30 5 2 5 6
M  V30 6 1 6 4
M  V30 7 1 2 7
M  V30 8 2 9 7
M  V30 9 2 10 8
M  V30 10 1 7 11
M  V30 11 1 8 9
M  V30 12 2 11 12
M  V30 13 1 12 10
M  V30 14 2 15 13
M  V30 15 2 16 14
M  V30 16 1 13 17
M  V30 17 1 14 15
M  V30 18 2 17 18
M  V30 19 1 18 16
M  V30 20 1 16 19
M  V30 21 2 21 19
M  V30 22 2 22 20
M  V30 23 1 19 23
M  V30 24 1 20 21
M  V30 25 2 23 24
M  V30 26 1 24 22
M  V30 27 2 27 25
M  V30 28 2 28 26
M  V30 29 1 25 29
M  V30 30 1 26 27
M  V30 31 2 29 30
M  V30 32 1 30 28
M  V30 33 1 30 31
M  V30 34 2 33 31
M  V30 35 2 34 32
M  V30 36 1 31 35
M  V30 37 1 32 33
M  V30 38 2 35 36
M  V30 39 1 36 34
M  V30 40 10 11 37
M  V30 41 10 37 29
M  V30 42 10 35 37
M  V30 43 10 37 21
M  V30 44 10 14 37
M  V30 45 10 37 4
M  V30 46 1 38 39
M  V30 47 1 38 40
M  V30 48 1 38 41
M  V30 49 1 38 42
M  V30 50 1 38 43
M  V30 51 1 38 44
M  V30 END BOND
M  V30 END CTAB
M  END
</chemform>
{{#moleculelink: |link=NSABRUJKERBGOU-UHFFFAOYSA-N|image=true}}

====Investigation====
{{#experimentlist: |form=Photocatalytic_CO2_conversion_experiments|name=Photocatalytic reduction of CO2: conditions optimization}}

{{#experimentlist: |form=Cyclic_Voltammetry_experiments|name=Cyclic voltammetry in various conditions}}

====Sacrificial electron donor====
In this study, the experiments were conducted with TEA ({{#moleculelink:|link=ZMANZCXQSJIPKH-UHFFFAOYSA-N|image=false|width=300|height=200}}), TEOA ({{#moleculelink:|link=GSEJCLTVZPLZKY-UHFFFAOYSA-N|image=false|width=300|height=200}}), and DIPEA ({{#moleculelink:|link=JGFZNNIVVJXRND-UHFFFAOYSA-N|image=false|width=300|height=200}}) as sacrificial electron donors.

====Additives====
In some experiments described in this study, TFE ({{#moleculelink:|link=RHQDFWAXVIIEBN-UHFFFAOYSA-N|image=false|width=300|height=200}}) was used as an additive.
[[Category:Photocatalytic CO2 conversion to CH4]][[Category:Publication]]