Photoelectrochemical reduction of CO2 on Cu/Cu2O films: Product distribution and pH effects

Autor(es)

de Brito, Juliana Ferreira ^[1] ; Araujo, Angela Regina ^[1] ; Rajeshwar, Krishnan ^[2] ; Boldrin Zanoni, Maria Valnice ^[1]

Afiliação do(s) autor(es)

^[1] UNESP, Inst Chem Araraquara, BR-14800900 Araraquara, SP - Brazil

^[2] Univ Texas Arlington, Dept Chem & Biochem, Arlington, TX 76019 - USA

• Tipo de documento: Artigo Científico
• Fonte: CHEMICAL ENGINEERING JOURNAL; v. 264, p. 302-309, MAR 15 2015.
• Citações Web of Science: 37

Resumo

This work focuses on photoelectrochemical CO2 reduction at a Cu/Cu2O electrode (1 x 1 cm(2)). The formation of methanol, ethanol, formaldehyde, acetaldehyde, and acetone was monitored during UV-visible radiation for 3 h at +0.20 V (vs. Ag/AgCl reference); 80% of the initial CO2 was removed. In this process, the photogenerated electrons in the p-type Cu2O semiconductor reduced CO2 (CO2 + e(-) --> CO2-center dot). Subsequent reaction involved radical species that originated during photolysis and dictated the product distribution observed. Methanol formation prevailed for a short period (<30 min); acetaldehyde and acetone were the main products after a longer accumulation period (>120 min). A reaction scheme is presented to account for the product evolution and reactions with the H-center dot, CH3 center dot, and OH center dot radical species generated in situ. The medium pH was identified as a key variable in the selectivity of the methanol formation. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 12/02725-0 - Estudo da redução fotoeletrocatalítica de CO2 usando eletrodos de nanotubos de TIO2, TIO2/Pt e eletrodos de Cu/CuO
• Beneficiário: Juliana Ferreira de Brito
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 08/10449-7 - Avaliação da ocorrência, toxicidade/genotoxicidade e processos para degradação de corantes em efluentes e águas superficiais
• Beneficiário: Maria Valnice Boldrin
• Modalidade de apoio: Auxílio à Pesquisa - Temático