The surface diffusion barriers of H increase in the following Au series: (110) < (111) < (100) < (211). The presence of low-coordinated Au atoms significantly reduces the surface adsorption barrier of H. A U-shaped dependence of the surface diffusion energy of H on the centres of the s- and d-bands of the gold atoms has been revealed.

Abstract

Calculations showed that hydrogen adsorption into subsurface sites is most likely to occur on Au (110) and (211) faces. The presence of low-coordinated Au atoms on significantly reduces the barrier of subsurface adsorption of H. The barriers of H surface diffusion increase in the following Au series: (110) < (111) < (100) < (211). An analysis of the dependence of the surface diffusion barriers on the electronic structure of gold atoms on the respective faces revealed a U-shaped dependence of the centers of the s- and d-bands. This dependence is the result of the filling of the s- and d-bands on different faces of the gold. The results obtained suggest that it is possible to use band centers to determine surface diffusion barriers.