Synergistic Ni Single Atoms/Nanoparticles on CeO ₂ for High‐Performance and Durable SOFC Hydrogen Electrodes

ABSTRACT Degradation of the three‐phase boundaries in Ni‐based anodes at high operating temperature compromises hydrogen oxidation reaction catalytic activity and shortens the lifespan of solid oxide fuel cells. Herein, an oxide‐based anode decorated with Ni single atoms (SAs) and nanoparticles (NPs), i.e., e‐Ni/CeO ₂ –5%, is synthesized by combining engineering of UiO‐66(Ce) metal organic frameworks (MOFs) and exsolution, where (i) Ni SAs donate electrons to generate oxygen vacancies and stabilize Ni NPs, (ii) NPs dissociate H ₂ to facilitate hydrogen spillover, and (iii) the abundant mesoporous channels in CeO ₂ inherited from the unique MOFs structure enables high‐efficient mass transfer. Synergy of the above merits finally delivers a greatly improved peak power density of 1.46 W cm ⁻² at 800°C among oxide‐based anodes, exhibits remarkable durability with negligible voltage degradation (< 0.005% h ⁻¹ ) over 500 h.