IR EVIDENCE FOR THE FORMATION OF TILTED CO ON ALUMINA-SUPPORTED NICKEL-CATALYST

An infrared inactive CO formed on Ni/Al2O3 catalyst has been evidenced by the co-adsorption of H2 at room temperature. The IR inactive CO on Ni/Al2O3 could convert into infrared detectable forms, linear and bridged CO, when the catalyst with the preadsorbed CO is exposed to H-2, and could also transform into linear and bridged CO as the catalyst is warmed in vacuum. The IR inactive CO might be the tilted CO, whose C-O axis is tilted with respect to the nickel surface normal or is nearly parallel to the nickel surface.