Interrupted-temperature programmed desorption of hydrogen over silica-supported platinum catalysts: the distribution of activation energy of desorption and the phenomena of spillover and reverse spillover of hydrogen

The surface heterogeneity of silica-supported platinum catalysts was characterized by interrupted temperature programmed desorption (TPD) of hydrogen. It was suggested that hydrogen spillover occurred and spiltover hydrogen moved from the support to the metal at high temperatures (reverse spillover), influencing the TPD spectrum. The distribution of activation energy of desorption for the surface of the metal was determined by a method that was recently developed by the authors. The results of desorption kinetics for the platinum catalysts were compared with the previous ones for silica-supported nickel catalysts. The reverse spillover was discussed briefly with a simplified model.