Density functional theory study of catalysis of Ir atoms deposited on γ-Al2O3 (001) surface

摘要

Iridium adsorption on γ-Al2O3 (001) surface has been studied using the ab initio calculation method (calculated by Material studio 3.1)and the electronic structures of the bare and the Ir adsorbed γ-Al2O3 (001) surfaces have been analyzed. By modeling different adsorption sites, one can conclude that the energetically most favorable sites for the Ir are the top sites of the O atoms in theγ-Al2O3 (001) surface terminated with octahedral Al. Charge redistribution around the Ir atom adsorbed on the surface improves the activity of the Ir atom as a catalyst. To evaluate the catalysis efficiency of the Ir atom adsorbed on the γ-Al2O3 (001) surface, ethene hydrogenation reaction was, taken as an example, simulated with the nudged elastic band method. It is found that the activation energy barrier is substantially lowered by the adsorbed Ir atom on the γ-Al2O3 (001), which facilitates the reaction throughout the ethene hydrogenation process.