An effect was demonstrated for the addition of lanthanum and cerium oxides to Pt/Al/sub 2/O/sub 3/ catalysts on the catalyst activity in the extensive oxidation of butane. Independently of the rate of the butane and oxygen concentrations in the gas phase, the specific catalyst activity (SCA) per m/sup 2/ Pt of the modified samples is less than that of the Pt/Al/sub 2/O/sub 3/ catalyst. The addition of lanthanum and cerium significantly increases the dispersion and stability of the supported platinum upon overheating. The IR spectra of the CO molecular probe were used to establish the electronic states of the surface platinum atoms in the samples studied after various treatments. In the presence of cerium oxide, platinum was found to undergo reduction with greater difficulty and have a greater tendency to undergo oxidation than platinum in the unmodified catalyst.