Ab initio insights into the structural, energetic, electronic, and stability properties of mixed CenZr15-nO30 nanoclusters

Autor(es)

Felicio-Sousa, Priscilla ^[1] ; Mucelini, Johnatan ^[1] ; Zibordi-Besse, Larissa ^[1] ; Andriani, Karla F. ^[1] ; Seminovski, Yohanna ^[2] ; Prati, Ronaldo C. ^[3] ; 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] Univ Politecn Valencia, Inst Tecnol Quim, Avda los Naranjos S-N, E-46022 Valencia - Spain

^[3] Fed Univ ABC, Ctr Math Comp Sci & Cognit, Av Estados 5001, BR-09210580 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physical Chemistry Chemical Physics; v. 21, n. 48, p. 26637-26646, DEC 28 2019.
• Citações Web of Science: 0

Resumo

Mixed CeO2-ZrO2 nanoclusters have the potential to play a crucial role in nanocatalysis, however, the atomistic understanding of those nanoclusters is far from satisfactory. In this work, we report a density functional theory investigation combined with Spearman rank correlation analysis of the energetic, structural and electronic properties of mixed CenZr15-nO30 nanoclusters as a function of the composition (n = 0, 1, horizontal ellipsis ,14, 15). For instance, we found a negative excess energy for all putative global minimum CenZr15-nO30 configurations with a minimum at about n = 6 (i.e., nearly 40% Ce), in which both the oxygen anion surroundings and cation radii play a crucial role in the stability and distribution of the chemical species. We found a strong energetic preference of Zr4+ cations to occupy larger coordination number sites, i.e., the nanocluster core region, while the Ce4+ cations are located near vacuum exposed O-rich regions. As expected, we obtained an almost linear decrease of the average bond lengths by replacing Ce4+ by Zr4+ cations in the (ZrO2)(15) nanoclusters towards the formation of mixed CenZr15-nO30 nanoclusters, which resulted in a shift towards higher vibrational frequencies. Besides, we also observed that the relative stability of the mixed oxides is directly correlated with the increase (decrease) of the Zr d-state (Ce f-state) contribution to the highest occupied molecular orbital with the increase of the Zr content, hence driving the gap energy towards higher values. (AU)

• Processo FAPESP: 18/11152-0 - Desenvolvimento de catalisadores para conversão direta de metano em metanol: uma investigação ab initio utilizando a da Teoria Funcional da Densidade
• Beneficiário: Karla Furtado Andriani
• 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