Effect of V2O5 Loading on Propane Combustion over Pt/V2O5–Al2O3 Catalysts

Propane combustion was studied on Pt(0.4%)/V2O5–Al2O3 catalysts containing up to 20% V2O5. The density, strength and nature of surface acid sites were determined by TPD of NH3 and FTIR spectra of adsorbed pyridine. The sample acidity increased with the vanadium content, essentially because the addition of vanadium oxide generated Brønsted acid sites. The Pt dispersion as determined by H2 chemisorption increased with increasing V2O5 loading. The sample activity for propane combustion was evaluated through both conversion versus temperature (light-off curves) and kinetically-controlled conversion versus time catalytic tests. The propane combustion turnover rate on Pt/V2O5–Al2O3 increased with the amount of vanadium, probably because the intrinsic Pt oxidation activity increases with the sample acidity.