Synthesis of Pt–Ru nanoparticles with a bifunctional stabilizer

A synthetic method for bimetallic Pt–Ru nanoparticles with a bifunctional stabilizer, (3-aminopropyl)trimethoxysilane (APS), is proposed. Sodium borohydride was used to induce simultaneous reduction of platinum and ruthenium ions in the presence of APS. The concentration of each metal ion was 0.06 mM, and sodium borohydride concentration was 10 times higher than the total metal ion concentration. X-ray diffraction measurement showed that the nanoparticles formed by the reduction contained alloy of Pt and Ru. Comparison of the Pt–Ru nanoparticles prepared in the presence of APS with those in the absence of APS confirmed that APS played a role of stabilizer in synthesis of the nanoparticles. The number-averaged size of Pt–Ru nanoparticles could be varied in the range of 2.1–3.7 nm at APS concentrations of 0.13–0.26 mM, and the narrowest size distribution of Pt–Ru nanoparticles appeared with the minimum average size (2.1 nm) around an APS concentration of 0.1 mM.