Synthesis and characterization of supported Pt and Pt alloys nanoparticles used for the catalytic oxidation of sulfur dioxide

Controlled pore glass silica (CPG) was used as support to prepare platinum-based catalysts using the wet impregnation method and DMSO or CHCl3 as solvent. In all cases, the catalyst loading with the active phase was 2 wt%. The catalysts were tested for the SO2 oxidation reaction at atmospheric pressure in the temperature range of 250–700 °C. The effect of doping the active metal with rhodium and palladium was also studied. The catalytic activities of the supported catalysts were found to follow the order Pt–Pd/CPG > Pt–Rh/CPG > Pt/CPG. A significant synergistic effect of the Pt–Pd alloy was observed compared with the SO2 conversion efficiency of the individual metals supported on CPG. The effect of the solvent used in the impregnation step is also discussed with regard to the properties of the final product and to catalytic activity.