Synthesis of carbon-PtAu nanoparticle hybrids originating from triethoxysilane-derivatized ionic liquids for methanol electrooxidation and the catalytic reduction of 4-nitrophenol

A facile and effective procedure for the synthesis of PtAu nanoparticles-carbon (PtAu-C) via the carbonization of triethoxysilane-derivatized ionic liquids is reported. A triethoxysilyl-functionalized ionic liquid, 1-methyl-3-[3-(triethoxysilyl)propyl]imidazolium chloride ([Si-pim][Cl]) was synthesized and anion-exchanged with a Pt precursor (H2PtCl6) and a Au precursor (HAuCl4) to form [Si-pim][PtCl6](x)[AuCl4](y) (the suffixes x and y represent the relative molar ratios of Pt and Au in the feed, respectively). The carbonization of [Si-pim][PtCl6](x)[AuCl4](y), followed by hydrofluoric acid (HF) etching, produced PtxAuy-C hybrids. The composition of the PtxAuy alloy NPs can be controlled simply by adjusting the feed ratio in the metal precursor solution. The electrocatalytic properties of the prepared PtxAuy-C hybrids were determined by the composition of the alloy NPs. The resultant Pt-C hybrids show high electroactivity towards methanol oxidation in an acidic medium, while Pt4Au1-C shows high activity towards the reduction of 4-nitrophenol. The present study provides a highly efficient approach for the development of high-performance noble metals and their alloy-based catalysts.