PtRu overlayers on Au nanoparticles for methanol electro-oxidation

PtRu overlayer structures were deposited on the surface of carbon-supported Au nanoparticles with atomic-scale thicknesses and their activity for methanol electro-oxidation was examined. The results of transmission electron microscopy, X-ray diffraction, and cyclic voltammetry demonstrated that the PtRu deposited uniformly on Au nanoparticles. The peak potential in CO stripping analysis shifted to higher potentials with decreasing amounts of PtRu, indicating stronger Pt–CO and Ru–CO bonding. PtRu utilization was enhanced with decreasing PtRu, which might be attributed to the overlayer structures on Au substrates. In methanol electro-oxidation, a negative effect of the strengthened Pt–CO and Ru–CO bonding on surface specific activity and a positive effect of PtRu utilization on mass specific activity might contribute competitively to overall activity for methanol electro-oxidation.