Spin effects in oxygen electrocatalysis: a discussion

The reduction of molecular oxygen in triplet and singlet spin states at metal electrodes is analyzed in the framework of quantum mechanical theory of charge transfer. Both outer- and inner-sphere mechanism is considered. Singlet oxygen is argued to be considerably more active in electron transfer pr...

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Detalhes bibliográficos
Autores: Nazmutdinov, Renat R., Santos, Elizabeth del Carmen, Schmickler, Wolfgang
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/25372
Acesso em linha:http://hdl.handle.net/11336/25372
Access Level:acceso abierto
Palavra-chave:Electron Transfer
Quantum Mechanical Theory
Electrocatalysis Oxygen Reduction
Spin Effects Singlet Molecular Oxygen
https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
Descrição
Resumo:The reduction of molecular oxygen in triplet and singlet spin states at metal electrodes is analyzed in the framework of quantum mechanical theory of charge transfer. Both outer- and inner-sphere mechanism is considered. Singlet oxygen is argued to be considerably more active in electron transfer processes. It is demonstrated that spin polarization may play a catalytic role, parallel with the effect of overlap of reactant orbitals with the d-band of a metal electrode. Our model is based on two main assumptions: (i) some metal surfaces favor the existence of singlet molecular oxygen in adsorbed state; and (ii) short-living singlet O2 molecules may appear as intermediates at some reduction steps. These two reasons are expected to increase the local concentration of active singlet molecular oxygen in reaction layer.