The Effect of the Surface Composition of Ru-Pt Bimetallic Catalysts for Methanol Oxidation

• DOI: 10.1016/j.electacta.2016.02.134
• Publication Date: 2016-02-24T22:09:06Z
• Authors: Taylor R. Garrick; Weijian Diao; John M. Tengco; Eric A. Stach; Sanjaya D. Senana...; Donna A. Chen; John R. Monnier; John W. Weidner
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract A series of Ru-Pt bimetallic catalysts prepared by the electroless deposition of controlled and variable amounts of Ru on the Pt surface of a commercially-available 20 wt% Pt/C catalyst has been characterized and evaluated for the oxidation of methanol. The activity of each Ru-Pt catalyst was determined as a function of surface composition via cyclic voltammetry. For the Ru-Pt bimetallic catalysts, activity passed through a maximum at approximately 50% monodisperse Ru surface coverage. However, due to the monolayer coverage of Ru on Pt, the amount of metal in the catalyst is minimized compared to a bulk 1:1 atomic ratio of Ru:Pt seen in commercial bimetallic catalysts. Chemisorption and temperature programmed reduction experiments confirmed that the surface had characteristics of a true bimetallic catalyst. On a mass of Pt basis, the activity of this composition for methanol oxidation was 7 times higher than pure Pt and 3.5 times higher than a commercial catalyst with a 1:1 Pt:Ru bulk atomic ratio.