Tailoring Zirconia Supported Intermetallic Platinum Alloy via Reactive Metal‐Support Interactions for High‐Performing Fuel Cells

Developing efficient and anti‐corrosive oxygen reduction reaction (ORR) catalysts is of great importance for the applications of proton exchange membrane fuel cells (PEMFCs). Herein, we report a novel approach to prepare metal oxides‐supported intermetallic Pt alloy nanoparticles (NPs) via the reactive metal‐support interaction (RMSI) as ORR catalysts, using Ni‐doped cubic ZrO2 (Ni/ZrO2) supported L10‐PtNi NPs as a proof of concept. Benefiting from the Ni migration during RMSI, the oxygen vacancy concentration in the support is increased, leading to an electron enrichment of Pt. The optimal L10‐PtNi‐Ni/ZrO2‐RMSI catalyst achieves remarkably low mass activity (MA) loss (17.8%) after 400,000 accelerated durability test cycles in a half‐cell and exceptional PEMFC performance (MA = 0.76 A mgPt−1 at 0.9 V, peak power density = 1.52/0.92 W cm−2 in H2‐O2/‐air, and 18.4% MA decay after 30,000 cycles), representing the best reported Pt‐based ORR catalysts without carbon supports. Density functional theory (DFT) calculations reveal that L10‐PtNi‐Ni/ZrO2‐RMSI requires a lower energetic barrier for ORR than L10‐PtNi‐Ni/ZrO2 (direct loading), which is ascribed to a decreased Bader charge transfer between Pt and *OH, and the improved stability of L10‐PtNi‐Ni/ZrO2‐RMSI compared to L10‐PtNi‐C can be contributed to the increased adhesion energy and Ni vacancy formation energy within the PtNi alloy.