Improving Catalytic Efficiency in the Methanol Oxidation Reaction by Inserting Ru in Face-Centered Cubic Pt Nanoparticles Prepared by a New Surfactant, Tert-Octanethiol

Abstract

PtRu/C catalysts, which have different atomic percent ratios of Pt and Ru (Pt/Ru = 0.8 (catalyst A), 2.1 (catalyst B), and 3.5 (catalyst C)), were prepared using PtCl4 and RuCl3 as starting materials and tert-octanethiol as a surfactant for the first time. Each was characterized by X-ray diffraction, transmission electron microscopy, energy dispersive analysis, X-ray photoelectron spectroscopy, cyclic voltammetry, and elemental analysis, and their activities were determined toward the methanol oxidation reaction. It has been found that catalyst A is 6 times more active toward the methanol oxidation reaction compared to the commercial catalyst. X-ray diffraction results indicated that more than 90% of the ruthenium in catalyst A inserts into the face-centered cubic (fcc) Pt crystalline structure, while more than 90% of Ru, present in catalyst B, remains as crystalline and/or amorphous Ru and/or RuO2. In catalyst C, approximately half of the Ru incorporates into the fcc platinum crystalline structure. © 2008 American Chemical Society.