Autor(es)

Ocampo-Restrepo, Vivianne K. ^[1] ; Verga, Lucas G. ^[1] ; Da Silva, Juarez L. F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 125, n. 48, p. 26296-26306, DEC 9 2021.
• Citações Web of Science: 0

Resumo

The C-O bond dissociation of the CO2 molecule via the reverse water gas shift reaction is crucial for several reactions used as renewable alternatives for fuel synthesis. However, our atomistic understanding of this process on transition metal (TM) clusters, where quantum-size effects might play a significant role, is far from complete. Here, we addressed the C-O bond dissociation by redox and carboxyl routes on 13-atom TM (Fe, Co, Ni, Cu) clusters using density functional theory calculations and the climbing image nudged elastic band algorithm. From the potential energy profiles, we found that CO2 is prone to dissociate into adsorbed CO via the redox route with lower activation energies, E-a's, than the carboxyl route on all studied TM13 systems. Our results suggested that the smaller activation barrier found on the Co-13 cluster is due to the stronger adsorption exhibited for both CO2 and O. By increasing the d-state occupation (from Fe to Cu), the E-a differences between CO2 dissociation and COOH formation decrease. We associated this behavior with a decrease in the (CO2 + H) adsorption energy from Fe-13 to Cu-13 that facilitates the COO-H bond formation and H-TM bond cleavage, i.e., favoring the carboxyl route. Also, our analyses indicate that the adsorption energies of the CO2 and trans-COOH species are the best descriptors for the C-O bond dissociation via the redox and carboxyl routes, respectively. (AU)

• Processo FAPESP: 17/11631-2 - CINE: desenvolvimento computacional de materiais utilizando simulações atomísticas, meso-escala, multi-física e inteligência artificial para aplicações energéticas
• Beneficiário: Juarez Lopes Ferreira da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa Aplicada
• Processo FAPESP: 19/05561-7 - Simulações Mutiescala Aplicadas à Redução do CO2 em Nanopartículas Metálicas: Efeitos de Tamanho das Nanopartículas e Concentração de Adsorvatos
• Beneficiário: Lucas Garcia Verga
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/21401-7 - EMU concedido no processo 2017/11631-2: cluster computacional de alto desempenho - ENIAC
• Beneficiário: Juarez Lopes Ferreira da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários