The effect of Sn on the electronic state of M/γ-Al₂O₃(M = Pd, Pt) catalysts and the influence in the catalytic combustion of methane

Pd-Sn and Pt-Sn catalysts supported on γ-Al2O3 were prepared by co-precipitation and the Pt characterized dispersion of reduced samples was determined by H2 chemisorption for Pt and Pt-Sn catalysts, The Pd dispersion was determined by CO adsorption on Pd and Pd-Sn catalysts. The catalysts were characterized by the electron binding energy values determined by XPS. The results are explained on the basis of the Pt and Pd species electron binding energy changes due to the electronic properties of Sn. The catalytic activity in methane oxidation under lean burn conditions was measured. The results reveal that the tin addition causes a change in the catalytic activity of the supported catalysts, showing a greater catalytic activity on the CH4-O2 reaction for the bimetallic Pd-Sn/ γ-Al2O3.