Cation‐Vacancy‐Enriched Nickel Phosphide for Efficient Electrosynthesis of Hydrogen Peroxides

Abstract Electrocatalytic hydrogen peroxide (H 2 O 2 ) synthesis via the two‐electron oxygen reduction reaction (2e ORR) pathway is becoming increasingly important due to the green production process. Here, cationic vacancies on nickel phosphide, as a proof‐of‐concept to regulate the catalyst's physicochemical properties, are introduced for efficient H 2 O 2 electrosynthesis. The as‐fabricated Ni cationic vacancies (V Ni )‐enriched Ni 2− x P‐V Ni electrocatalyst exhibits remarkable 2e ORR performance with H 2 O 2 molar fraction of >95% and Faradaic efficiencies of >90% in all pH conditions under a wide range of applied potentials. Impressively, the as‐created V Ni possesses superb long‐term durability for over 50 h, suppassing all the recently reported catalysts for H 2 O 2 electrosynthesis. Operando X‐ray absorption near‐edge spectroscopy (XANES) and synchrotron Fourier transform infrared (SR‐FTIR) combining theoretical calculations reveal that the excellent catalytic performance originates from the V Ni ‐induced geometric and electronic structural optimization, thus promoting oxygen adsorption to the 2e ORR favored “end‐on” configuration. It is believed that the demonstrated cation vacancy engineering is an effective strategy toward creating active heterogeneous catalysts with atomic precision.