A computational investigation of H2adsorption and dissociation on Au nanoparticles supported on TiO2 surface

Abstract

The specific role played by small gold nanoparticles supported on the rutile TiO₂(110) surface in the processes of adsorption and dissociation of H₂ is discussed. It is demonstrated that the molecular and dissociative adsorption of H₂ on Au_n clusters containing n = 1, 2, 8 and 20 atoms depends on cluster size, geometry structure, cluster flexibility and the interaction with the support material. Rutile TiO₂(110) support energetically promotes H₂ dissociation on gold clusters. It is demonstrated that the active sites towards H₂ dissociation are located at corners and edges on the surface of the gold nanoparticle in the vicinity of the support. The low coordinated oxygen atoms on the TiO₂(110) surface play a crucial role for H₂ dissociation. Therefore the catalytic activity of a gold nanoparticle supported on the rutile TiO₂(110) surface is proportional to the length of the perimeter interface between the nanoparticle and the support.