Pseudo‐Jahn–Teller Effect Breaks the pH Dependence in Two‐Electron Oxygen Electroreduction

Abstract The hydrogenation of small molecules (like O2 and CO2) often exhibits strong activity dependence on pHs because of discrepant proton donor environments. However, some catalysts can show seldom dependence on two‐electron oxygen electroreduction, a sustainable route of O2 hydrogenation to hydrogen peroxide (H2O2). In this work, a pH‐resistant oxygen electroreduction system arising from the pseudo‐Jahn–Teller effect is demonstrated. Thorough operando Raman spectra, local environment analyses and density function theory simulations, the lattice distortion of TiOxFy that introduces the pseudo‐Jahn–Teller effect contributing to regulating local pHs at electrode–electrolyte interfaces and the absorption/desorption of key *OOH intermediate is revealed. Consequently, as comparison to 78.6% activity attenuation for common catalyst, the TiOxFy displays minor activity decay (3.2%) in the pH range of 1–13 with remarkable Faradaic efficiencies (93.4–96.4%) and H2O2 yield rates (595–614 mg cm−2 h−1) in the current densities of 100–1000 mA cm−2. Further techno‐economics analyses display the H2O2 production cost dependent on pHs, giving the lowest H2O2 price of $0.37 kg−1. The present finding is expected to provide an additional dimension to pseudo‐Jahn–Teller effect that leverages systems beyond traditional conception.