Infrared Studies of CO Adsorption on Reduced and Oxidized Pt/TiO2

摘要

Carbon monoxide adsorption experiments were studied on reduced and oxidized Pt/Ti02 with Ft-IR. On reduced samples two kinds of linear CO species were observed and assigned as adsorption on Pt close-packed (terrace) sites 1/2094 cm. In addition a bridged CO species was found at 1/1854 cm. Both linear species show increasing frequencies with coverage. Saturation CO uptake decreases with increasing substrate reduction temperature and there is a preferential decrease of linear CO CO species on terrace sites and the concentration of bridged species lies below detection limits. On oxidized Pt/Ti02 samples, some Pt atoms are covered with oxygen atoms and the density of step sites is enhanced. (Author)