Abstract
We report the synthesis and catalytic application of intermetallic PtSn nanoparticles confined in MSWs (Mesoporous Silica Wells) in the semi-hydrogenation of acetylene. Platinum nanoparticles with a size of 2.9 nm supported on amine-functionalized similar to 180 nm silica spheres were enmeshed in a mesoporous silica shell. After the addition of tin via a polyol synthesis method, we obtained the final PtSnx@MSW (x=0.30, 0.50, 0.70, 1.0 and 2.0). Owing to the mesoporous encapsulation the sub-5 nm bimetallic particles are shown to be monodisperse and well protected against aggregation on the silica sphere even under high-temperature treatment conditions. In the gas phase semi-hydrogenation of acetylene, the PtSn@MSW with Sn/Pt molar ratios equal to or greater than one displayed higher selectivity to ethylene. Meanwhile, increasing Sn content decreases acetylene conversion. The intermetallic PtSn@MSW catalysts also displayed long-term stability and regenerability due to the confined environment provided by MSW.