The aim of this work was to examine Pt/Al2 0 3 , Pt-Sn/Al2C>3 and Pt/Sn(>2 catalysts for the oxidation of l-butane. The main conclusion which can be drawn from this study is that, although less active initially compared with the Pt/SnC>2 and Pt/Al203 samples, the Pt-Sn/Al203 catalysts were more resistant to thermal aging, maintaining a higher catalytic activity than the former catalysts after aging at 1073K. For example for 5wt% Pt/Al2C>3, 5wt% Pt/Sn0 2 and 5wt% Pt, 3wt% S11/AI2O3 catalysts pnor to aging the light off temperatures (LOTs) were 43 3K, 428K and 468K respectively After aging the LOTs for the corresponding samples was 478K, 499K and 468K respectively. There was no correlation between Pt particle size and activity. For the majonty of catalysts examined there was an increase in catalytic activity at a distinct temperature compared with initial activity, which may have been due to a secondary reaction or to the presence of different catalytic sites on the surface of the catalysts. The AI2O3 support material consisted mostly of rj-A^C^ and was stable up to 1070K, but at higher temperatures the surface area and pore volume decreased. Treatment of the AI2O3 with HNO3 or HC1 (to increase support acidity) led to an increase in surface area. High temperature exposure of acid treated samples caused a more rapid decrease in surface area initially and the formation of higher amounts of a- AI2O3 compared with the untreated AI2O3, possibly due to the formation of cation vacancies during acid pretreatment Addition of the cations La3"1", Si^+ and Ce^+ to the untreated AI2O3 had little effect on surface area loss at 1370K but prevented (X-AI2O3 formation. After 48h at 1370K the surface area of untreated AI2O3 and acid pre-treated AI2O3 was similar, and the major cause of surface area loss was not due to (X-AI2O3 formation, but possibly pore loss. Preparation variables for Pt/Al2C>3 catalysts were examined Pre-treatment of the AI2O3 support with HNO3 led to an increase in Pt uptake, higher Pt dispersion and higher catalytic activity compared with untreated catalysts studied while pre-treatment with HC1 or H2O had the opposite effect. The method of impregnation also affected the catalysts, with spray impregnation being the most effective method Drying at 31 OK for 16h after impregnation led to a nonhomogeneous distribution of Pt. The HC1 and H2O pre-treated catalysts exhibited an increase in activity after reduction in H2, the opposite being the case for the other Pt/Al203 catalysts examined. In Pt-Sn/Al203 catalysts Sn was present in the form of Sn(II) and/or Sn(IV) and also as a Sn-aluminate species From H2 chemisorption measurements, Sn loadings <lwt% led to higher uptakes of H2 compared to Pt/Al203 samples For Pt/Sn0 2 catalysts no detectable amounts of H2 chemisorption occurred and surface Pt was in the form of a substrate bonded species, Pt-O-Sn.