Phosphorylation Modulation of the Electronic Structure of CoMn Aerogels for Enhanced Oxygen Evolution Reaction in Alkaline Media

Developing inexpensive, highly active and stable nonprecious metal‐based electrocatalysts to improve the catalytic performance of oxygen evolution reaction (OER) is critical for realizing the large‐scale implementation of electrochemical water splitting, metal air batteries, and other green energy devices. Herein, we report a facile phosphorylation approach that can modulate the electronic structure of CoMn aerogel to improve the OER performance in alkaline media. The as‐prepared PO 4 3− ‐CoMn‐Aerogel catalyst exhibited excellent OER performance in 1 M KOH, evidenced by a low overpotential of 254.4 mV to afford a current density of 10 mA cm −2 and a small Tafel slope of 101.98 mV dec −1 , superior to the RuO 2 benchmark catalyst. Moreover, PO 4 3− ‐CoMn‐Aerogel demonstrated robust long‐term stability, as it was able to operate stably for 35 h without significant current decay. Multiple characterization techniques indicated that the phosphorylation dramatically modulates the electronic structure and local chemical microenvironment of the CoMn‐Aerogel. Density functional theory calculations validated that, at the equilibrium potential of 1.23 V, the transformation of *O to *OOH constitutes the rate‐determining step, and surface phosphorylation significantly lowers the associated free energy barrier to 0.82 eV. This study offers an effective strategy that can engineer the transition metal aerogel‐based electrocatalysts with improved catalytic performance toward OER.