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

AUTOR(ES)

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.

FONTE

J. Braz. Chem. Soc.

DATA DE PUBLICAÇÃO

2016-11

RESUMO

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.

Documentos Relacionados

• The effect of precursors salts on surface state of Pd/Al2O3 and Pd/CeO2/Al2O3 catalysts
• Effect of Metal Dispersion on the Hydrogenation of 2-Amyl Anthraquinone over Pd/Al2O3 Catalyst
• Study of Nd3+, Pd2+, Pt4+, and Fe3+ dopant effect on photoreactivity of TiO2 nanoparticles
• Innovative Coating Method of MgAl2O4 or ZnAl2O4 on α-Al2O3 Spheric Nuclei
• Propane oxidation on Pt-WO3/gamma -AL2O3 catalytic systems