Metastable Ni ₂ P Phase Transformation via Ce‐Mo Dual‐Modulation for Efficient Urea Electrolysis

ABSTRACT Electrocatalytic urea oxidation reaction (UOR) enables simultaneous wastewater purification and energy‐efficient hydrogen production, despite facing slow kinetics and competing oxygen evolution. Herein, a high‐performance Ce/Ni 2− x Mo x P catalyst was synthesized through Ce and Mo dual‐modulation to dynamically regulate Ni‐P phase transitions and construct atomic‐scale electron transfer networks. Investigations reveal that the Ce 3+ /Ce 4+ redox cycle triggers oxygen vacancy formation and steers the transition from stable Ni 3 P to metastable Ni 2 P, while Mo 6+ acts as an electron acceptor to optimize the electronic structure of Ni sites. Their synergistic interaction significantly lowers the phase transition barrier and boosts urea adsorption/activation. The catalyst achieves a current density of 100 mA cm ‒2 at a low potential of 1.32 V for UOR and demonstrates exceptional stability. Moreover, a urea electrolysis system constructed based on the optimized Ce/Ni 2− x Mo x P bifunctional catalyst reaches 400 mA cm ‒2 at just 1.68 V, significantly outperforming conventional water electrolysis, as well as maintaining operation for over 460 h at 500 mA cm ‒2 with a minimal decay rate of 0.11 mV h ‒1 . This work elucidates the atomic‐scale mechanism of Ce‐Mo cooperative regulation of electronic structure and phase transformation, providing a new strategy for designing efficient non‐noble‐metal electrocatalysts and advancing the industrialization of urea electrolysis.