Robust and Efficient Pd–Cu Bimetallic Catalysts with Porous Structure for Formic Acid Oxidation and a Mechanistic Study of Electrochemical Dealloying

To obtain highly efficient and robust electrocatalysts for formic acid oxidation, PdxCuy/C binary catalysts with porous structures were successfully prepared via electrochemical dealloying. Catalysts with different Pd/Cu atomic ratios were characterized through transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, and X-ray diffraction. The optimized dealloyed Pd1Cu4/C catalyst with a porous structure displayed a catalytic activity of 2611 A g−1 and high stability (30.5% activity retention under repeated cyclic voltammetric (CV) patrol), whereas a commercial Pd/C-Aldrich benchmark showed a catalytic activity of 785 A g−1 and retained 16.5% activity. A detailed mechanistic study of electrochemical dealloying was performed. Under repeated CV patrol, Pd-enriched porous architectures evolved from Pd-poor surfaces, accompanied by successive Cu dissolution.