Molecular dynamics investigation of the structural and energetic properties of CeO2-MOx (M = Gd, La, Ce, Zr) nanoparticles

Autor(es)

de Mendonca, Joao Paulo A. ^[1] ; Lourenco, Tuanan C. ^[1] ; Freitas, Luis Paulo M. ^[2] ; Santo, Anderson A. E. ^[2] ; Feliciano, Gustavo T. ^[2] ; Da Silva, Juarez L. F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Chem, POB 780, BR-13560970 Sao Carlos, SP - Brazil

^[2] Sao Paulo State Univ, Inst Chem, POB 55, BR-14800900 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS ADVANCES; SEP 2021.
• Citações Web of Science: 0

Resumo

CeO2-based materials have played a critical role in catalysis, where the substrate particles have reduced in size year by year due to experimental achievements in synthesis control. Thus, there is increasing interest to improve our atomistic understanding of the structural and energetic properties of mixed CeO2-based nanoparticles of 1 nm to 5 nm. Here, we employed classical molecular dynamics (MD) simulations to study the following solid solutions, CeO2-Gd2O3, CeO2-La2O3, CeO2-Ce2O3, and CeO2-ZrO2, using 5 compositions (0, 25, 50, 75, and 100%). The amorphization and re-cystallization process via MD simulations was employed to generate the nanoparticles, which were characterized by several analyses. We found that even in small CeO2 concentrations, the systems maintain the cubic fluorite structure and the truncated octahedron shape found in pure ceria, evidencing the strong influence of Ce4+ on the nanoparticle morphology due to the higher phase transition temperature of the CeO2 compound. On the other hand, the addition of the 3+ species leads to the spontaneous appearance of higher concentrations of solvated cations and vacancies near to the surface of the CeO2-based solutions. Beyond that, the 3+ species also influence the electrostatic potential in the nanoparticle surface, and hence controlling the 3+-4+ ratio may be an interesting approach to control the nanoparticle physicochemical properties for catalytic purposes. (AU)

• Processo FAPESP: 19/23681-0 - De métodos ab initio até o contínuo para a busca de materiais para baterias de sódio-íon
• Beneficiário: Tuanan da Costa Lourenço
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• 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 em Engenharia
• 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