Supported metals are used extensively in heterogeneous catalysis. In the present investigation platinum is loaded onto titania and titania-alumina supports to study the SMSI effects in detail. The catalysts were characterized by X-ray Diffraction(XRD), Stepwise Temperature Programmed Reduction (STPR) and chemisorption measurements. All the samples exhibit characteristic behaviour showing SMSI effect after HTR, though there is only moderate interaction in the mixed oxide sample. From STPR studies, the reducibility of platinum and the support in supported platinum systems is shown to depend on the extent of the interaction at the interface. © 1998 Elsevier Science B.V. All rights reserved.