P and O Co‐Doped Pt‐Co Octahedral Nanocrystals as Highly Active and Stable Electrocatalysts for Oxygen Reduction Reaction

Abstract The development of high active and stable Pt−M (M=transition metals) electrocatalysts for oxygen reduction reaction (ORR) is crucial for the commercialization of proton exchange membrane fuel cells (PEMFCs). The main challenge of Pt−M electrocatalysts is their instability, mainly due to the leaching of M. In this study, we report the design of P and O co‐doped octahedral PtCo alloy on Ketjen carbon black (P x ‐Oct PtCo/C) through a seed‐mediated synthesis. In‐situ FTIR spectroscopy revealed that P 0.61 ‐Oct PtCo/C has the lowest d‐band center, thereby enhancing the catalytic activity. The strong interaction formed by chemical bond between O and Co in P x ‐Oct PtCo/C, observed by EXAFS spectra effectively inhibited the dissolution of Co and improved the ORR stability. The mass activity and specific activity of P 0.61 ‐Oct PtCo/C can reach 0.61 A mg Pt −1 and 2.4 mA cm −2 , respectively, which is 4.1 times and 10.9 times higher than that of commercial Pt/C. After 50,000 potential cycles, the loss of mass activity is only 25 %, surpassing the DOE 2025 target of less than 40 % loss after 30,000 cycles. This study offers an alternative approach to enhancing the activity and durability of Pt−M electrocatalysts for the ORR.