Suppressing Metal Dissolution in Multi‐Grained Catalysts Through Intragrain Atomic Ordering for Stable Fuel Cells

Abstract Rational design of catalytic nanomaterials is essential for developing high‐performance fuel cell catalysts. However, structural degradation and elemental dissolution during operation pose significant challenges to achieving long‐term stability. Herein, the development of multi‐grained NiPt nanocatalysts featuring an atomically ordered Ni 3 Pt 5 phase within intragrain is reported. Ultrasound‐assisted synthesis facilitates atomic transposition by supplying sufficient diffusion energy along grain boundaries, enabling unprecedented phase formation. The Ni 3 Pt 5 embedded nanocatalysts exhibit outstanding proton exchange membrane fuel cell performance under both light‐duty and heavy‐duty vehicle conditions, with significantly reduced Ni dissolution. Under light‐duty vehicle conditions, the catalyst achieves a mass activity of 0.94 A mg Pt −1 and a 421 mA cm −2 current density (@ 0.…