Low-pressure hydrogenation of CO2 to methanol over Ni-Ga alloys synthesized by a surfactant-assisted co-precipitation method and a proposed mechanism by DRIFTS analysis

Autor(es)

Rasteiro, Leticia F. ^[1] ; Rossi, Marco A. L. S. ^[1] ; Assaf, Jose M. ^[2] ; Assaf, Elisabete M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Chem IQSC, Av Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Chem Engn Dept, Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CATALYSIS TODAY; v. 381, n. SI, p. 261-271, DEC 1 2021.
• Citações Web of Science: 1

Resumo

Ni-Ga alloy catalysts were synthesized by a surfactant-assisted co-precipitation method and were tested in CO2 hydrogenation to methanol at 10 bar and at ambient pressure. The presence of surfactant in the synthesis led to a decrease in particle size, with the catalyst produced using 1% of surfactant (C\_1%) presenting the smallest and most homogeneous particle size. A difference between the catalysts was also observed in the change of the crystalline phase after the reaction, where the C\_1% catalyst presented the lowest loss of the Ni5Ga3 active phase. Methanol productivity showed positive relations with smaller particle size and higher quantity of Ni5Ga3 crystalline phase remaining after the reaction, with the C\_1% catalyst presenting the highest methanol productivity. Catalytic evaluation under different conditions showed that higher temperature and GHSV values led to poorer selectivity to methanol. The C\_1% catalyst also presented good activity at ambient pressure and remained stable after 5 h, with no deactivation. A mechanistic study employing DRIFTS analyses found that the reaction pathway on Ni-Ga alloy involved both the RWGS and formate routes, as shown by the presence of formate, methoxy, and CO intermediates. (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: 17/22671-5 - Nanopartículas de Ga-Ni suportados em sílica porosa para a síntese de metanol a partir do CO2 em baixas pressões
• Beneficiário: Letícia Fernanda Rasteiro
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• 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
• Processo FAPESP: 17/10154-6 - Estudo de catalisadores baseados em nanocompósitos do tipo metal-óxido dopados e encapsulados por revestimento mesoporoso para a obtenção do metanol a partir da hidrogenação do CO2
• Beneficiário: Marco Aurélio de Lima Silva Rossi
• Modalidade de apoio: Bolsas no Brasil - Doutorado