The Investigation of Sm/Ni Model Catalysts:IV. Interaction of CO with the Sm/Ni Surface

The adsorption and reaction of CO on the Sm overlayer and Sm/ Ni alloy surfaces have been investigated with TDS and AES. The CO is adsorbed dissociatively on Sm overlayer. and can oxidize Sm to form SmO_x and surface carbon which associatively desorb at high temperature of - 1000K. CO adsorption on Sm/Ni surface alloys leads to disruption of alloy phase and induces the segregation and aggregation of Sm₂O_x on the surface. The corresponding TD spectrum of CO appears to be similar to that observed on clean Ni surface. The CO preadsorbed on Sm Ni surface alloy can be displaced by oxygen, while the preadsorbed oxygen completely suppress any further uptake of CO.