Investigation of Electrocatalysts for Selective Reduction of CO2 to CO: Monitoring the Reaction Products by on line Mass Spectrometry and Gas Chromatography

Autor(es)

Mariana R. Camilo ^[1] ; Wanderson O. Silva ^[2] ; Fabio H. B. Lima ^[3]

Afiliação do(s) autor(es)

^[1] Universidade de São Paulo. Instituto de Química de São Carlos - Brasil

^[2] Universidade de São Paulo. Instituto de Química de São Carlos - Brasil

^[3] Universidade de São Paulo. Instituto de Química de São Carlos - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 28, n. 9, p. 1803-1815, 2017-09-00.

Resumo

The carbon dioxide electrocatalytic reduction is central for the development of regenerative cycles of electrochemical energy conversion and storage. Herein, the gaseous products of the CO2 electroreduction were monitored by using an electrochemical cell on line coupled to a differential electrochemical mass spectrometer (DEMS), aiming at searching for electrocatalysts with high selectivity for CO formation. The results showed that, among the studied materials, the Cu4Sn/C alloy nanoparticles were stable during potentiostatic polarizations as revealed by in situ X-ray absorption spectroscopy (XAS), and the on line DEMS measurements showed the production of CO, suppression of methane and ethylene formations, and diminishing of the hydrogen evolution reaction, in relation to that on pure Cu2O-Cu/C. The faradaic efficiencies for CO formation were 13 and 23% for Cu4Sn/C and Au/C (a known electrocatalyst for CO), respectively, determined by experiments of in line gas chromatography (GC). The selectivity of Cu4Sn/C for CO formation was ascribed to the role of Sn atoms on stabilizing adsorbed HCOO intermediates, and hindering further hydrogenation, letting CO free for desorption. These results are expected to be used as a guide for further development of electrocatalysts with a fine-tuning of composition for increasing the faradaic efficiency of CO2 electroreduction to CO. (AU)

• Processo FAPESP: 16/13323-0 - Eletroquímica do Dióxido de Carbono e da Água: Aplicação em Estocagem e Aproveitamento de Energia
• Beneficiário: Fabio Henrique Barros de Lima
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/16930-7 - Eletrocatálise V: processos eletrocatalíticos de interconversão entre as energias química e elétrica
• Beneficiário: Edson Antonio Ticianelli
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/26699-3 - Desenvolvimento de eletrocatalisadores para a eletrorredução de CO2 e foto-eletrooxidação da água: investigação dos produtos reacionais por espectrometria de massas on-line em fluxo
• Beneficiário: Mariana Romano Camilo Casale
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado