Decoupling Oxygen Reduction From Hydrogen Oxidation on Platinum via Phosphorus Coordination for Reversal‐Tolerant and Durable PEM Fuel Cells

ABSTRACT

During the start‐up/shut‐down (SU/SD) processes of proton‐exchange membrane fuel cells (PEMFCs), anode reversal generates an excessively high voltage that accelerates corrosion of the cathode Pt/C catalyst. Conventional approaches focus on blocking the delivery of oxygen or electrons to the anode, but fail to address the intrinsic activity coupling of Pt/C for both hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). Here, we report a strategy that can selectively tailor the catalytic function of Pt nanoparticles. We used phosphorus to modulate the electronic structure of low‐loading Pt clusters on a carbon support, forming a Pt/P‐BP catalyst. The P‐coordination downshifts the d ‐band center of Pt cluster, as evidenced by in situ ATR‑FTIR spectroscopy and DFT calculations, thereby widening the activity gap between HOR and ORR. Specifically, compared to Pt/C, Pt/P‐BP enhances HOR mass activity by fivefold while substantially suppressing ORR, transforming Pt from a bifunctional catalyst into a highly selective HOR catalyst. Consequently, Pt/P‐BP achieves a 10.8‐fold higher HOR/ORR selectivity than Pt/C. In SU/SD experiments, the Pt/P‐BP anode significantly reduces carbon corrosion of the cathode catalyst layer, maintaining the fuel cell performance better than Pt/C. This work paves a new avenue toward durable PEMFCs and inspires the selectivity design for electrocatalysts.