Electrocatalytic metal hydride generation using CPET mediators.
Nature
; 607(7919): 499-506, 2022 07.
Article
em En
| MEDLINE
| ID: mdl-35859199
ABSTRACT
Transition metal hydrides (M-H) are ubiquitous intermediates in a wide range of enzymatic processes and catalytic reactions, playing a central role in H+/H2 interconversion1, the reduction of CO2 to formic acid (HCOOH)2 and in hydrogenation reactions. The facile formation of M-H is a critical challenge to address to further improve the energy efficiency of these reactions. Specifically, the easy electrochemical generation of M-H using mild proton sources is key to enable high selectivity versus competitive CO and H2 formation in the CO2 electroreduction to HCOOH, the highest value-added CO2 reduction product3. Here we introduce a strategy for electrocatalytic M-H generation using concerted proton-electron transfer (CPET) mediators. As a proof of principle, the combination of a series of CPET mediators with the CO2 electroreduction catalyst [MnI(bpy)(CO)3Br] (bpy = 2,2'-bipyridine) was investigated, probing the reversal of the product selectivity from CO to HCOOH to evaluate the efficiency of the manganese hydride (Mn-H) generation step. We demonstrate the formation of the Mn-H species by in situ spectroscopic techniques and determine the thermodynamic boundary conditions for this mechanism to occur. A synthetic iron-sulfur cluster is identified as the best CPET mediator for the system, enabling the preparation of a benchmark catalytic system for HCOOH generation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prótons
/
Catálise
/
Eletroquímica
/
Transporte de Elétrons
/
Complexos de Coordenação
Idioma:
En
Revista:
Nature
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Suíça