Computational–experimental assessment of transition-metal doping of Co3O4 for acidic oxygen evolution reaction with balanced activity and stability

Abstract

Acidic water oxidation using earth-abundant oxides remains challenging because of sluggish kinetics and poor stability under oxygen evolution reaction (OER) conditions. Herein, density functional theory was used to systematically screen fourth-row transition-metal dopants in Co₃O₄ and establish joint activity–stability descriptors. It was found that early-series dopants improve the lattice thermodynamic stability, while chromium maximizes the electrochemical stability. Enhanced OER activity correlated with moderate values of the d-band center, metal–oxygen covalency, and integrated crystal orbital Hamiltonian population, indicating an optimal bonding regime. Chromium has emerged as an optimal dopant, striking a balance between stability and activity of the catalyst. Guided by these predictions, experiments demonstrated that 10% Cr-doped Co₃O₄ exhibited excellent OER performance, achieving an overpotential of 366 mV at 10 mA cm⁻² in 0.5 M H₂SO₄ and improving durability 2.7-fold, with only an 11 mV increase in overpotential after extended testing. This combined computational–experimental study outlines a generalizable pathway for identifying effective dopants for oxide catalysts in acidic OER by concurrently optimizing stability and catalytic activity.