Efficient photocatalytic hydrogen production in water using a cobalt(iii) tetraaza-macrocyclic catalyst: electrochemical generation of the low-valent Co(i) species and its reactivity toward proton reduction
| Autor: | Jérôme Fortage, Alain Deronzier, Carmen E. Castillo, Marie-Noëlle Collomb, Allan G. Blackman, Florian Molton, Thibaut Stoll, Siddhartha Varma |
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| Přispěvatelé: | Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE), Département de Chimie Moléculaire (DCM), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes - UFR Médecine (UGA UFRM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]) |
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Aqueous solution
010405 organic chemistry Chemistry Inorganic chemistry General Physics and Astronomy chemistry.chemical_element Electron donor engineering.material 010402 general chemistry Ascorbic acid 01 natural sciences 7. Clean energy 0104 chemical sciences Catalysis chemistry.chemical_compound Photocatalysis engineering [CHIM]Chemical Sciences Noble metal Physical and Theoretical Chemistry Cobalt ComputingMilieux_MISCELLANEOUS Hydrogen production |
| Zdroj: | Physical Chemistry Chemical Physics Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2013, 15 (40), ⟨10.1039/c3cp52641k⟩ |
| ISSN: | 1463-9076 1463-9084 |
| DOI: | 10.1039/c3cp52641k⟩ |
| Popis: | A very efficient homogeneous system for visible-light driven hydrogen production in water is reported. This comprises the [Co(CR)Cl2](+) cobalt(III) tetraaza-macrocyclic complex (Cat1) as a noble metal-free catalyst, [Ru(bpy)3]Cl2 as a photosensitizer and ascorbate/ascorbic acid as a sacrificial electron donor and buffer. This system gives up to 1000 turnovers at pH 4.0 versus the catalyst with a relatively low photosensitizer/catalyst ratio (10/1) and a high concentration of catalyst (1 × 10(−4) M), thus producing a significant amount of H2 (12.3 mL for 5 mL of solution). It also exhibits long-term stability (more than 20 hours). The efficiency of Cat1 has been compared under the same experimental conditions to those of three other H2-evolving catalysts, which are known to operate in water, [Co{(DO)(DOH)pn}Br2] (Cat2), [Co(dmbpy)3]Cl2 (Cat3) and [Rh(dmbpy)2Cl2]Cl (Cat4). These comparative studies show that Cat4, although based on a noble metal, is about four times less active, while Cat2 and Cat3 produce more than one hundred times less hydrogen than Cat1. The low-valent CoI form of Cat1 has been successfully electrogenerated in CH3CN. Its high stability can be related to the high catalytic performance of the Cat1 system. We have also shown that in acidic aqueous solution (photocatalytic conditions) reduction at a slightly more negative potential than the Co(II)/Co(I) couple is needed to ensure efficient catalysis; this reduction is performed by the photogenerated [Ru(II)(bpy)2(bpy(˙−))](+) species. |
| Databáze: | OpenAIRE |
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