Promoting and inhibiting effect of SO2 on propane oxidation over Pt/A12O3

SO2 adsorption, SO2 oxidation and oxidation of propane with oxygen in the absence and the respective presence of SO2 in the feed gas were studied over unsulfated and sulfated 1% Pt/gamma-Al2O3. Results showed that the promoting effect Of SO2 in the reaction flux on C3H8 oxidation over 1% Pt/gamma-Al2O3 depends on the presulfating temperature. Catalytic activity measurements and FTIR absorption spectra showed that during propane oxidation, Pt/support interfacial adsorbed species were formed at temperatures 25-300 degreesC, inhibiting C3H8 oxidation. However, at higher temperatures these Pt/support interfacial adsorbed species were oxidized, leading to Pt/support interfacial sulfate species, which strongly promote propane oxidation. (C) 2002 Elsevier Science B.V. All rights reserved.