A computational investigation of H2 adsorption and dissociation on Au nanoparticles supported on TiO2 surface

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.