ADSORPTION OF HYDROGEN ON NI AND NI-TIO2 COMPOSITE ULTRAFINE PARTICLES

The adsorption of hydrogen on Ni and Ni-TiO2 composite ultrafine parti cles (UFPs) was studied by temperature-programmed desorption (TPD) exp eriments. The desorption characteristics of hydrogen on Ni and Ni-TiO2 composite UFPs were similar to those of a Ni single crystal or polycr ystal. The amount of adsorption of hydrogen on Ni-TiO2 composite UFPs was dependent upon the temperature of exposure, and the phenomenon att ributed to the spillover of hydrogen from Ni onto TiO2. The CO hydroge nation reaction on Ni-TiO2 composite UFPs proceeded above 373 K. TPD s pectra showed new desorption peaks after the catalytic reaction above 373 K and suggested the formation of new adsorption states.