Electrocatalytic Activity Enhancement of Pd Nanoparticles Supported on Reduced Graphene Oxide by Surface Modification with Au

Abstract

The surface modification of Pd nanoparticles supported on reduced graphene oxide (Pd/RGO) with a small amount of Au and the electrocatalytic oxidation of propane-1,2-diol on the Au-modified Pd/RGO (Au/Pd/RGO) are investigated. The modification of Pd/RGO was performed by electrochemically deposing Au on the Pd surfaces. Characterizations by transmission electron microscopy, scanning electron microscopy and X-ray diffraction analyses and electrochemical analysis revealed that Pd nanoparticles were finely distributed on RGO and a small part of the Pd surface was covered by Au. The Au-modified Pd/RGO catalysts show higher activity than Pd/RGO for propane-1,2-diol oxidation in alkaline solution. For example, the peak intensity for Au/Pd/RGO with a Au:Pd atomic percent of 1.67% is about 2 times higher than that for Pd/RGO. On the other hand, the activity enhancement of bulk Pd electrode by the modification with Au is less effective. The results show that the modification of Pd/RGO catalysts with a small amount of Au is very effective for activity improvement, and the as-prepared catalysts also have a great advantage over AuPd alloy or core-shell catalysts in cost.