Dispersion of MoO3, NiO, ZnO on rutile TiO2 with low specific surface area wasstudied with Mercury Porosimeter, SEM, XPS and Ammonia Extraction method. The dispersionthresholds of MoO3, NiO, ZnO on three rutile TiO2 carriers were obtained with XPS, and com-pared with those on anatase TiO2 with high specific surf are area. Ammonia Extraction methodwas used to identify the surface oxide species interarting with support surface in different strengthand it was found that the proportions of oxides that can not be extrarted by ammonia extractionare different for MoO3, NiO and ZnO which are supported on rutile TiO2.
A flat and compact Al2O3 film of 20urn in thickness was prepared on the substrate of Si wafer by magnetic controlled sputtering Al reaction with O2 in Ar. A small amount of MoO3 was va- porized in vacuum and deposited onto a slot in a covering film on the surface of A12O3 film. The samples were heated in dry or wet N2, O2 and air respectively, characterized by TRSRF, AES, XPS, XRD and SEM to study the surface diffusion of MoO3 on the A12O3 film. The results show that MoO3 can diffuse on the surface of Al2O3 film by heating the samples at 573K or 673K. The diffusion rate increases with the heating temperature. moisture can accelerate the diffusion rate of MoO3 on the surface of Al2O3.
