Negatively Charged Pt Atoms on Pd Nanocubes for an Enhanced Hydrogen Oxidation Performance in a Membrane Electrode Assembly

Proton-exchange membrane fuel cells (PEMFCs) constitute an advanced clean technology that efficiently transforms hydrogen energy into electricity. However, the hydrogen oxidation reaction (HOR) at the anode heavily depends on precious metal catalysts, posing economic challenges for PEMFCs commercialization. Consequently, developing cost-effective, high-activity HOR catalysts for anodes is imperative. In this study, we developed a bimetallic Pd–Pt electrocatalyst for acidic HOR, enhancing the catalytic activity by modulating the electron transfer between the metals. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy confirmed the presence of negatively charged Pt atoms. Electrochemical tests showed that PdPt 0.1 exhibited exceptional catalytic activity, with mass activities 3.2 and 11.5 times higher than those of commercial Pt/C and Pd/C, respectively. Moreover, in membrane electrode assembly tests, PdPt 0.1 achieved a power density of 1.19 W cm –2, outperforming commercial Pt/C with a power density of 0.85 W cm –2 . These remarkable performances are attributed to electron transfer between Pd and Pt, reducing the hydrogen binding energy during HOR. This study offers valuable insights for the controlled design of HOR catalysts based on the electron-transfer direction.