Facile Synthesis of Gold-Modified Platinum Catalysts with High Performance for Formic Acid Electro-oxidation

A facile, eco-friendly method for the synthesis of gold/platinum catalysts through electrodeposition of platinum nanoparticles, followed by the deposition of solutions of HAuCl₄ onto the surface of pre-prepared platinum for a galvanic replacement reaction, is reported. Different molar ratios of bimetallic structures of platinum and gold could be easily achieved and characterized by energy-dispersive X-ray spectroscopy, SEM, and XRD. Electrochemical measurements reveal that the electrocatalytic activities of these series of gold/platinum catalysts towards formic acid oxidation reaction are superior to that of pure platinum. In addition, the formic acid oxidation route is related to the molar ratio of gold to platinum, which can be ascribed to the influence of gold. The gold/platinum catalyst with a platinum to gold atomic ratio of 2.51:1 exhibits maximum activity. Moreover, this optimized molar ratio shows a highly stable electrocatalytic activity for CO antipoisoning effects. These experimental results suggest that the prepared gold/platinum catalysts have great potential for applications in fuel cells.