The origin of SO2-promoted propane oxidation over Pt/alumina catalysts has been elucidated utilising spectroscopic and kinetic measurements over dispersed Pt/Al2O3 and model γ-Al2O3/Pt(111) systems. HREELS, NEXAFS, TPRS and XPS studies show that under oxidising conditions SO2 promotes the dissociative chemisorption of C3H8 at both Pt and support sites via surface sulphation. Interfacial sulphoxy species play a key role in activating propane for subsequent combustion at metal sites via a bifunctional spillover mechanism. The loading dependence of the promotional effect is rationalised in the light of X-ray and TEM measurements that reveal catalyst sulphation is accompanined by the reduction and concomitant sintering of small (<20 ) PtO2 particles to form large, active Pt metal clusters.
|Number of pages||6|
|Journal||Studies in surface science and catalysis|
|Publication status||Published - 2000|
|Event||12th International Congress on Catalysis - Granada, Spain|
Duration: 9 Jul 2000 → 14 Jul 2000