Ab initio molecular dynamics study of H-2 adsorption on sulfur- and chlorine-covered Pd(100)

作者：Gross Axel^*

来源：Surface Science, 2013, 608: 249-254.

DOI：10.1016/j.susc.2012.10.015

• Palladium
• Hydrogen
• Density functional theory calculations
• Poisoning
• Adsorption dynamics
• Subsurface penetration

The adsorption of molecular hydrogen on sulfur- and chlorine-covered Pd(100) in a (2 x 2) geometry is studied by ab initio molecular dynamics simulations. The potential energy surfaces of H-2/S(2 x 2)/Pd(100) and H-2/CI(2 x 2)/Pd(100) are rather similar. Consequently, also the dependence of the sticking probability on incident kinetic energy, angle of incidence and internal excitations are very close. For H-2/S(2 x 2)/Pd(100), previous results obtained on an interpolated ab initio potential energy surface are confirmed, except for the dependence of the sticking probability on the initial rotational state which exhibits a surprising rotational enhancement. Discrepancies with respect to the experiment which remain are discussed. In the simulations, several subsurface penetration events have been found, preferentially close to the sulfur or chlorine adatoms, respectively. This is explained by lower barriers caused by the destabilization of hydrogen adsorption close to the repulsive adatoms.

• 出版日期2013-2