Reactivity of radiolytically and photochemically generated tertiary amine radicals towards a CO2 reduction catalyst DOI Open Access
Cody R. Carr, Michael Vrionides, David C. Grills

et al.

The Journal of Chemical Physics, Journal Year: 2023, Volume and Issue: 159(24)

Published: Dec. 26, 2023

Homogeneous solar fuels photocatalytic systems often require several additives in solution with the catalyst to operate, such as a photosensitizer (PS), Brønsted acid/base, and sacrificial electron donor (SED). Tertiary amines, particular triethylamine (TEA) triethanolamine (TEOA), are ubiquitously deployed photocatalysis applications SEDs capable of reductively quenching PS's excited state. Upon oxidation, TEA TEOA form TEA•+ TEOA•+ radical cations, respectively, which decay by proton transfer generate redox non-innocent transient radicals, TEA• TEOA•, potentials that allow them participate an additional step, thus resulting net one-photon/two-electron donation. However, properties TEOA• radicals not well understood, including their reducing powers kinetics catalysts. Herein, we have used both pulse radiolysis laser flash photolysis CH3CN, combined UV/Vis absorption time-resolved mid-infrared spectroscopies, probed reduction well-established CO2 photocatalyst, fac-ReCl(bpy)(CO)3 (bpy = 2,2'-bipyridine), these [kTEA• (4.4 ± 0.3) × 109 M-1 s-1 kTEOA• (9.3 0.6) 107 s-1]. The ∼50× smaller rate constant for indicates, contrast previous assumption, is more potent reductant than (by ∼0.2 V, estimated using Marcus cross relation). This knowledge will aid design involving SEDs. We also show can be useful radiolytic solvent scavenger experiments effectively converting unwanted oxidizing into equivalents radicals.

Language: Английский

Influence of a neighbouring Cu centre on electro- and photocatalytic CO2 reduction by Fe-Mabiq DOI

Kerstin Rickmeyer,

Matthías Huber,

Corinna R. Hess

et al.

Chemical Communications, Journal Year: 2023, Volume and Issue: 60(7), P. 819 - 822

Published: Dec. 14, 2023

Electrocatalytic and photocatalytic CO

Language: Английский

Citations

5
Iron, Cobalt and Nickel complexes with N4-donor ligands catalysts for the CO2 photoreduction DOI Creative Commons

Nassima El Aouni,

Ali Aghmiz, Mar Reguero

et al.

Molecular Catalysis, Journal Year: 2024, Volume and Issue: 565, P. 114392 - 114392

Published: July 19, 2024

Iron(II), cobalt(II) and nickel (II) complexes bearing phenanthroline- bipyridine-bis(imino) ligands have been prepared tested as catalysts for the photoreduction of CO2 at atmospheric pressure room temperature in presence a photosensitizer (PS) sacrificial electron donor (SD) producing mixtures CO H2. The best results were obtained with Fe(II) catalyst using triethanolamine/1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzoimida-zole (BIH) acetonitrile blue LED irradiation [Ru(bpy)3]PF6]2 (bpy = 2,2′-bipyridine) PS. With this system, mixture CO/H2 (68/32) was turnover number (TONCO 166, 24 h). Analogous Co(II) Ni(II) produced H2 major product. Cyclic voltammetry demonstrates that electrons uptake is centered on ligand. Computational calculations allow to propose most stable location electrons.

Language: Английский

Citations

1
Selective and Efficient Light-Driven CO2 Reduction to CO with a Heptacoordinated Polypyridine Iron(II) Catalyst DOI
Federico Droghetti, Florian Lemken, Lubomı́r Rulı́šek

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(22), P. 16920 - 16935

Published: Nov. 1, 2024

The selective generation of carbon-based products in the presence proton donors currently represents one major goals catalysis CO2 reduction reaction (CO2RR). Within this framework, iron complex 1-([2,2′-bipyridin]-6-yl)-N-([2,2′-bipyridin]-6-ylmethyl)-N-(pyridin-2-ylmethyl) methanamine ligand (DBPy-PyA) turns out to be a and efficient catalyst promote conversion into CO. In present work, we report detailed experimental computational investigation CO2RR by metal complex. Efficient formation CO (selectivity >90%) was attained under electrochemical conditions (applied potential −2.0 V vs Fc+/Fc) using trifluoroethanol as donor, which provides best balance, among those tested, terms Lewis Brønsted acidity. This is indeed instrumental accelerating activation while minimizing parallel hydrogen byproduct. high activity selectivity toward were shown arise from (i) ability assist via intramolecular routes metallacarboxylic acid catalytic intermediate, (ii) favorable almost barrierless detachment product putative iron(II) carbonyl (iii) weak tendency two-electron-reduced form metal-hydride species. titled further investigated light-driven with [Ru(bpy)3]2+ (bpy = 2,2′-bipyridine) sensitizer N,N-diisopropylethylamine (DIPEA) electron leading unprecedented performances 1 sun irradiation (0.85 mL per solution, quantum yield 9.4%, >97%, solely limited degradation sensitizer). Transient absorption spectroscopy suggested that, for three-component photochemical system examined, photogenerated reductant rate-determining step photosynthetic process. With information hand, carefully modulating photon flux, succeeded achieving more than 3-fold enhancement (up 28%). All all, our study showcases great, but often underestimated, molecular target transformations.

Language: Английский

Citations

1
Transferring enzyme features to molecular CO2 reduction catalysts DOI Creative Commons

Matthías Huber,

Corinna R. Hess

Current Opinion in Chemical Biology, Journal Year: 2024, Volume and Issue: 83, P. 102540 - 102540

Published: Nov. 15, 2024

Language: Английский

Citations

0
Reactivity of radiolytically and photochemically generated tertiary amine radicals towards a CO2 reduction catalyst DOI Open Access
Cody R. Carr, Michael Vrionides, David C. Grills

et al.

The Journal of Chemical Physics, Journal Year: 2023, Volume and Issue: 159(24)

Published: Dec. 26, 2023

Homogeneous solar fuels photocatalytic systems often require several additives in solution with the catalyst to operate, such as a photosensitizer (PS), Brønsted acid/base, and sacrificial electron donor (SED). Tertiary amines, particular triethylamine (TEA) triethanolamine (TEOA), are ubiquitously deployed photocatalysis applications SEDs capable of reductively quenching PS's excited state. Upon oxidation, TEA TEOA form TEA•+ TEOA•+ radical cations, respectively, which decay by proton transfer generate redox non-innocent transient radicals, TEA• TEOA•, potentials that allow them participate an additional step, thus resulting net one-photon/two-electron donation. However, properties TEOA• radicals not well understood, including their reducing powers kinetics catalysts. Herein, we have used both pulse radiolysis laser flash photolysis CH3CN, combined UV/Vis absorption time-resolved mid-infrared spectroscopies, probed reduction well-established CO2 photocatalyst, fac-ReCl(bpy)(CO)3 (bpy = 2,2'-bipyridine), these [kTEA• (4.4 ± 0.3) × 109 M-1 s-1 kTEOA• (9.3 0.6) 107 s-1]. The ∼50× smaller rate constant for indicates, contrast previous assumption, is more potent reductant than (by ∼0.2 V, estimated using Marcus cross relation). This knowledge will aid design involving SEDs. We also show can be useful radiolytic solvent scavenger experiments effectively converting unwanted oxidizing into equivalents radicals.

Language: Английский

Citations

1