Active copper species of co-precipitated copper-ceria catalysts in the CO-PROX reaction: An in situ XANES and DRIFTS study

Autor(es)

Miranda Cruz, Aline Rodrigues ^[1] ; Assaf, Elisabete Moreira ^[2] ; Gomes, Janaina Fernandes ^[1] ; Assaf, Jose Mansur ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Engn Quim, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim Sao Carlos, Av Trab Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CATALYSIS TODAY; v. 381, p. 42-49, DEC 1 2021.
• Citações Web of Science: 0

Resumo

Properties of co-precipitated CuO/CeO2 catalysts with nominal content of 1-3 wt.% copper were investigated by EDS, XRD, BET, STEM, EDS map, H-2-TPR, in situ DRIFTS and in situ XANES. By comparing results of DRIFTS, XANES and catalytic performance in the CO-PROX reaction, it was evidenced a relationship between the catalytic behavior and the copper oxidation state of the materials. In situ DRIFTS and XANES analyses shed light on the oxidation state of active copper species involved in the CO-PROX reaction between 120 degrees C and 200 degrees C. The investigated catalysts present a balance between Cu degrees and Cu+ species under PROX conditions and the Cu+ is the main species liable to adsorb CO. Furthermore, our studies indicated that the PROX reaction on CuO/CeO2 is impacted by the nature of Cu species, which in turn may vary with reaction temperature, depending on the Cu content. From these results, we propose a new mechanism of PROX reaction on CuCe catalysts, including Cu+/ Cu3+ and Ce3+/Ce4+ redox pairs and direct CO oxidation on Cu degrees. (AU)

• Processo FAPESP: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 15/06246-7 - Aplicação do conceito de biorrefinaria a estações de tratamento biológico de águas residuárias: o controle da poluição ambiental aliado à recuperação de matéria e energia
• Beneficiário: Marcelo Zaiat
• Modalidade de apoio: Auxílio à Pesquisa - Temático