| Abstract
| - The adsorption and reaction of CH3OH on Pd and PdZn films and particles supported on the (0001) surfaceof a ZnO single crystal were studied using temperature-programmed desorption (TPD). At 300 K, vapor-deposited Pd films followed a two-dimensional island growth mode and preferentially blocked the activesites for dissociative adsorption of methanol on the ZnO(0001) surface. Upon heating, the Pd films agglomeratedinto particles and reacted with the ZnO substrate to form a PdZn alloy. Methanol was found to undergocomplete dehydrogenation on the supported Pd and PdZn films and particles producing CO and H2. Consistentwith previous studies, alloying of Pd with Zn decreased the strength of the interaction of CO with the metalsurface, as evidenced by a decrease in the CO desorption temperature. A low-temperature pathway for theoxidation of CO to CO2 on Pd/ZnO(0001) and PdZn/ZnO(0001), in which oxygen was supplied by the ZnO(0001) support, was also identified.
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