Simultaneous Interface Engineering and Phase Tuning of CeO2‐Decorated Catalysts for Boosted Oxygen Evolution Reaction

Abstract Heterogeneous catalysts have attracted extensive attention among various emerging catalysts for their exceptional oxygen evolution reaction (OER) capabilities, outperforming their single‐component counterparts. Nonetheless, the synthesis of heterogeneous materials with predictable, precise, and facile control remains a formidable challenge. Herein, a novel strategy involving the decoration of catalysts with CeO 2 is introduced to concurrently engineer heterogeneous interfaces and adjust phase composition, thereby enhancing OER performance. Theoretical calculations suggest that the presence of ceria reduces the free energy barrier for the conversion of nitrides into metals. Supporting this, the experimental findings reveal that the incorporation of rare earth oxides enables the controlled phase transition from nitride into metal, with the proportion adjustable by varying the amount of added rare earth. Thanks to the role of CeO 2 decoration in promoting the reaction kinetics and fostering the formation of the genuine active phase, the optimized Ni 3 FeN/Ni 3 Fe/CeO 2 ‐5% nanoparticles heterostructure catalyst exhibits outstanding OER activity, achieving an overpotential of just 249 mV at 10 mA cm −2 . This approach offers fresh perspectives for the conception of highly efficient heterogeneous OER catalysts, contributing a strategic avenue for advanced catalytic design in the field of energy conversion.