Unravelling the Non‐Concerted Proton Electron Transfer Mechanism of MOF‐Derived Manganese Incorporated Cerium Oxide for Superior Oxygen Evolution Reaction: Experimental Evaluation and DFT Validation

In water electrolysis, the oxygen evolution reaction (OER) plays a fundamental half‐cell reaction, and designing high‐performance electrocatalysts is crucial for advancing sustainable energy technologies. Herein, Ce/Mn bimetal MOF is thermally decomposed to produce (Ce‐Mn)O x /C, possessing Mn incorporated CeO 2 lattice and supported by a carbon matrix. The catalyst demonstrated only 237 mV of overpotential to reach 10 mA cm −2 and a Tafel slope of just 48 mV dec −1 with exceptional durability of over 25 h, outperforming many conventional OER catalysts. A comparative study of (Ce‐Mn)O x /C catalyst against its individual components, Mn‐PTA, Ce‐PTA, and their binary complex (Ce/Mn)‐PTA, substantiated these findings. Theoretical studies validated the experimental results, providing insights into the synergy existing between Ce and Mn within oxide lattice. Upon integration with Pt/C as a cathode into a full water splitting cell, the setup required only 1.57 V to deliver 10 mA cm 2 current density. This study highlights the potential of cerium‐based materials in advancing high‐performance and stable electrocatalysts for water electrolysis, contributing significantly to the advancement of next‐generation energy conversion technologies.