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

Abstract The hydrogenation of small molecules (like O 2 and CO 2 ) 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 O 2 hydrogenation to hydrogen peroxide (H 2 O 2 ). 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 TiO x F y 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 TiO x F y displays minor activity decay (3.2%) in the pH range of 1–13 with remarkable Faradaic efficiencies (93.4–96.4%) and H 2 O 2 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 H 2 O 2 production cost dependent on pHs, giving the lowest H 2 O 2 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.