Metal-Assisted Ligand-Centered Electrocatalytic Hydrogen Evolution upon Reduction of a Bis(thiosemicarbazonato)Cu(II) Complex
Date Published |
08/2017
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Publication Type | Journal Article
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Authors | |
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DOI |
10.1021/acs.inorgchem.7b0160810.1021/acs.inorgchem.7b01608.s001
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Abstract |
In this study, we report the electrocatalytic behavior of the neutral, monomeric Cu(II) complex of diacetyl-bis(N-4-methyl-3-thiosemicarbazonato), CuL1, for metal-assisted ligand-centered hydrogen evolution in acetonitrile and dimethylformamide. CuL1 displays a maximum turnover frequency (TOF) of 10 000 s–1 in acetonitrile and 5100 s–1 in dimethylformamide at an overpotential of 0.80 and 0.76 V, respectively. The rate law is first-order in catalyst and second-order in proton concentration. Gas analysis from controlled potential electrolysis confirms CuL1 as an electrocatalyst to produce H2 with a minimum Faradaic efficiency of 81% and turnover numbers as high as 73 while showing no sign of degradation over 23 h. The H2 evolution reaction (HER) was probed using deuterated acid, demonstrating a kinetic isotope effect of 7.54. A proton inventory study suggests one proton is involved in the rate-determining step. Catalytic intermediates were identified using 1H NMR, X-ray photoelectron, and UV–visible spectroscopies. All catalytic intermediates in the proposed mechanism were successfully optimized using density functional theory calculations with the B3LYP functional and the 6-311g(d,p) basis set and support the proposed mechanism. |
Journal |
Inorganic Chemistry
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Volume |
56
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Year of Publication |
2017
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Issue |
18
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Pagination |
11254 - 11265
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ISSN Number |
0020-1669
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Short Title |
Inorg. Chem.
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Refereed Designation |
Refereed
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Organizations | |
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