Synthesis of PtAu Alloy Nanocrystals Supported on Three-Dimensional Carbon with Enhanced Electrocatalytic Properties

Sub-nanosized PtAu particles within three-dimensional carbon materials were obtained via a mercaptosilane-assisted preparation method. This strategy can effectively control the size of PtAu particles while avoiding the use of an additional carbon precursor. The as-synthesized three-dimensional carbon (3D carbon) material possesses excellent properties compared to other carbon materials. PtAu particles on three-dimensional carbon (PtAu/3D carbon) exhibited superior activities for methanol oxidation and hydrogen evolution reactions compared to Pt/3D carbon and a commercial Pt/Carbon (Pt/C) catalyst. Specifically, the methanol peak current density on PtAu/3D carbon was almost 2.3 times higher than that of Pt/3D carbon and 1.9 times higher than that of commercial Pt/C. The Tafel slopes of PtAu/3D carbon, Pt/3D carbon, and the commercial Pt/C were approximately 112, 124, and 106 mV dec(-1), respectively, demonstrating that electrochemical desorption is the rate-limiting step in the hydrogen evolution reaction of the as-synthesized catalysts.