The Effect of Gamma-Al2O3 Support on the NO Adsorption on Pd4 Cluster

Autor: Prates,Letícia M., Ferreira,Glaucio B., Carneiro,José W. M., Almeida,Wagner B. de, Carauta,Alexandre N. M., Correia,Julio C. G., Cruz,Maurício T. M.
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Journal of the Brazilian Chemical Society, Volume: 27, Issue: 11, Pages: 2062-2069, Published: NOV 2016
Journal of the Brazilian Chemical Society v.27 n.11 2016
Journal of the Brazilian Chemical Society
Sociedade Brasileira de Química (SBQ)
instacron:SBQ
Popis: The effect of γ-Al2O3 support on the NO adsorption on Pd4 clusters was investigated by means of density functional theory (DFT) calculations. Pd4 adsorbed on γ-Al2O3 (represented by a Al14O24H6 cluster) changes its preferential geometry from tetrahedral to a distorted planar structure. The alumina support promotes a higher dispersion in the palladium catalyst and reduces the NO adsorption energy to -25.6 kcal mol-1 (computed at B3LYP/LANL2DZ/6-311+G(d)), in close agreement with the experimental value of -27.2 kcal mol-1. On the bare planar Pd4 cluster the NO molecule adsorbs in a bridge arrangement, with adsorption energy of -41.2 kcal mol-1. Adsorption on the tetrahedral Pd4 cluster occur preferentially in an atop mode, with adsorption energy of -30.6 kcal mol-1. Charge density analysis show that the electron flux between the NO molecule and Pd4 depends on the adsorption form, with back-donation being stronger in the bridge adsorption mode.
Databáze: OpenAIRE