Surface interaction between H2 and CO2 over silicalite-supported platinum

Infrared spectroscopic evidence is presented for the formation of linearly bonded CO species, as a result of surface interaction between H2 and CO2 at room temperature over silicalite-supported Pt. Comparison with direct CO adsorption results suggests that the active sites for this CO2 reaction are the corner or step sites on platinum particles. The CO formed on these active sites then migrates to other sites on the surface of Pt particles. Co-adsorbed hydrogen and water make the linearly bonded CO species more strongly adsorbed on Pt particles. However, exposure to oxygen or air at room temperature effectively removes these CO species.