Bimetallic Pt/Sn-based Nanoparticles in Ionic Liquids as Nanocatalysts for the Selective Hydrogenation of Cinnamaldehyde

The exceptional physico-chemical properties of ionic liquids are exploited for the synthesis and catalytic application of heterometallic nanoparticles. Pt/Sn-based nanoparticles with 2-3 nm diameter are synthesized by chemical reduction of the metal salt precursors in the ionic liquid (i.e., methyltrioctylammonium bis(trifluoromethylsulfonyl)imide) using triethylborohydride as reducing agent. Investigations by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy suggest the formation of randomly alloyed Pt/Sn-based nanoparticles. The tin precursor and the platinum to tin ratio of the precursors are shown to influence the nature of the nanoparticles. The selective hydrogenation of cinnamaldehyde is used to probe the catalytic performance of the Pt/Sn nanoparticles, demonstrating the effect of tin alloying on the catalytic activity and selectivity to the ,-unsaturated cinnamic alcohol.