Adsorption and dissociation mechanism of toluene on Pd (111) and PdO (101) surface: First principle calculation

Abstract

Metal Palladium species are efficiently used to degrade volatile organic compounds (VOCs). In this paper, the adsorption properties of toluene on Pd(111) and PdO(101) surfaces were theoretically studied using the first principle calculation. Adsorption energy, charge density, density of states and electron density difference were chosen as characteristics and were calculated to evaluate the adsorption capacity of toluene on Pd(111) and PdO(101) surfaces. The results showed that the interaction of toluene on the Pd(111) surface was stronger than on the PdO(101) surface. The dissociation pathway of toluene after adsorption was also determined; the results showed that the formation of benzyl radical through the reaction with a hydroxyl group on the Pd(111) and PdO(101) surfaces was investigated using density functional theory calculations. Compared with PdO(101) (0.63 eV), the dissociation of toluene on Pd(111) (0.19 eV) has a lower energy barrier, which indicated that the reaction between toluene and Pd(111) was easier to occur. Therefore, it provides the basis for the preparation of high-performance catalysts and the calculation of catalytic oxidation reaction paths in the future.