Ce doping-boosted lattice oxygen activation for NiCo2O4 in acidic oxygen evolution reaction

Developing low-cost non-noble electrocatalysts is crucial for acidic oxygen evolution reaction (OER); however, their performance still lags behind that of Ir-based catalysts. Herein, Ce-doped NiCo₂O₄ electrocatalysts were synthesized on carbon cloth (CC) by electrodeposition and subsequent calcination. The Ce doping effectively modulated the electronic redistribution of NiCo₂O₄, and Ce acted as a dynamic electron buffer to inhibit excessive oxidation of Co species during OER. The optimal 10 %Ce-NiCo₂O₄ exhibited an overpotential of 220 mV at 10 mA cm⁻² and maintained outstanding durability over 120 h, significantly outperforming undoped NiCo₂O₄ (353 mV; 40 h). Theoretical calculations and experimental results unraveled that Ce doping efficiently activated lattice oxygen oxidation and decreased the energy barrier of the rate-determining step, thereby favoring the involvement of the lattice oxygen oxidation mechanism (LOM) in 10 %Ce-NiCo₂O₄ during acidic OER. This work develops a promising strategy for constructing cost-effective electrocatalysts with high activity and stability in acidic OER.