A STUDY OF CO, NO, AND H2 ADSORPTION ON MODEL PT/CEO2 CATALYSTS

Model catalysts consisting of Pt particles on an amorphous CeO2 film have been investigated to determine the effect of ceria on the adsorption properties of Pt for CO, NO, and H-2. The catalysts were prepared by vapor deposition of Pt and the film growth was characterized by Auger electron spectroscopy. Film growth for Pt is the same on both ceria and an oxidized Al foil and appears to be three-dimensional at room temperature on both substrates. Temperature programmed desorption (TPD) results show strong variations in the adsorption properties for CO, NO, and H-2 as a function of particle size; however, the results for the model Pt/ceria catalysts were found to be identical to results for Pt on both oxidized Al or alpha-Al2O3(0001) when particles of the same size are compared. The results suggest that interactions between Pt and ceria are relatively weak within the temperature and pretreatment conditions studied and that the presence of ceria does not substantially affect the adsorption properties of Pt.