Synthesis of PtSn nanoparticles on carbon materials by different preparation methods for selective catalytic hydrogenation of citral

Abstract

In this work, PtSn bimetallic catalysts supported on three different carbons were prepared by two methods: a) conventional impregnation followed by a reduction treatment under H2-flow (CI) and b) deposition-reduction in liquid phase (RLP). All the catalysts were tested in the selective hydrogenation of citral to the unsaturated alcohols (UA). A strong influence of the preparation method and the support was found over the selectivity to UA. For CI prepared catalysts, low Sn loadings give a metallic phase with highly ordered PtSn alloys, while for RLP catalysts, high Sn loadings give highly ordered phases with Sn ionic species intercalated in the Pt metallic phase. Both ordered phases are highly effective to promote the hydrogenation of carbonyl group. For the RLP method, high Sn/Pt molar ratios in solution leads to the formation of PtSn complexes with a good interaction between metals.