Metal-Assisted Ligand-Centered Electrocatalytic Hydrogen Evolution upon Reduction of a Bis(thiosemicarbazonato)Cu(II) Complex.
Inorg Chem
; 56(18): 11254-11265, 2017 Sep 18.
Article
em En
| MEDLINE
| ID: mdl-28857556
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 10â¯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.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Inorg Chem
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos