IMPORTANCE OF SURFACE HYDROGEN CONCENTRATION IN ENHANCING ACTIVITY OF CO-NI ALLOY CATALYST FOR CO HYDROGENATION

The hydrogen-deuterium exchange reaction was employed for studying the reactivity of adsorbed hydrogen on Co-Ni alloy. The infrared spectra of adsorbed NO indicates that the support oxide electronically interacts with the Co-Ni alloy. Desorption measurements suggest that the electron density of the alloy greatly influences the surface coverage of hydrogen and carbon monoxide. The CO hydrogenation rate of Co-Ni alloy in the presence of CO was shown to be related to the H-2-D2 exchange rate. The dissociative adsorption of hydrogen in the presence of CO is of primary importance in determining the CO hydrogenation rate of the Co-Ni alloy system, since the preadsorbed CO species strongly hinder the hydrogen adsorption. A high surface concentration of active hydrogen in the presence of CO leads to high catalytic activity for CO hydrogenation on Co-Ni alloy.