Improvement of PROX-CO catalytical performance by modulation of the pore structure of CeO2 nanorods decorated with Au nanoparticles

Autor(es)

Machado Silva, Raul Bruno ; de Oliveira, Cristine Santos ; Teixeira-Neto, Erico ; Sigoli, Fernando Aparecido ; Mazali, Italo Odone

• Tipo de documento: Artigo Científico
• Fonte: Microporous and Mesoporous Materials; v. 330, p. 11-pg., 2022-01-06.

Resumo

Au/CeO2-based materials are widely investigated catalytical systems used for the preferential oxidation of CO (PROX-CO). Recent research focused on their improvement via the development and optimization of nanostructures, where both metal and oxide may be individually tailored to provide the best combination of catalytic performance, stability, and cost. In this work, we synthesized CeO2 porous nanorods using a facile hydrothermal synthesis and tailored their native porous structure using a simple acid lixiviation procedure to enlarge its pores and expose facets such as the {110} ones that are more susceptible to oxygen vacancy formation, one of the main requirements for PROX-CO. We decorated both lixiviated and as-synthesized CeO2 nanorods with Au nanoparticles using deposition-precipitation, and evaluated the effect of lixiviation over the morphology, structure, oxygen storage capacity and catalytic activity for PROX-CO. Through HRSTEM we observed an increase in the pore size while maintaining the morphology and structure of the nanorods. This increase was accompanied by the facilitation of oxygen vacancy formation, resulting in almost tripling the oxygen storage capacity (OSC). This impacted the performance of the CeO2/Au nanorods for PROX-CO, allowing a maximum of 88% CO conversion rate at 181 degrees C, compared to 27% and 238 degrees C for the non-lixiviated nanorods, under the same catalytical conditions. (AU)

• Processo FAPESP: 16/21070-5 - Espectroscopia vibracional com resolução espacial
• Beneficiário: Mauro Carlos Costa Ribeiro
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/22127-2 - Desenvolvimento de novos materiais estratégicos para dispositivos analíticos integrados
• Beneficiário: Lauro Tatsuo Kubota
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/07853-2 - Influência do design estrutural de nanobastões porosos de CeO2 decorados com nanopartículas bimetálicas na otimização da performance da reação de deslocamento do gás d'água
• Beneficiário: Raul Bruno Machado da Silva
• Modalidade de apoio: Bolsas no Brasil - Mestrado