Reactivity of mixed rhodium/aluminium thin films deposited on gamma-alumina

Abstract Rh and Al mixed thin films deposited on the gamma-alumina surface were studied. Auger electron spectroscopy as well as thermal desorption spectroscopy (TDS) results showed significant alloying of Rh and Al after the first annealing of the system. CO thermal desorption results were strongly influenced by the previous CO adsorption–desorption cycles, showing strong CO adsorbate–induced reversible changes on the surface. TDS and molecular beam reactive scattering (CO oxidation) results depended on Rh:Al atomic ratio significantly. Shapes of CO oxidation curves were similar to the results obtained on clean Rh foil previously and their intensity also corresponded to Rh surface concentration.