Accelerated Proton‐Coupled Electron Transfer via Engineering Palladium Sub‐Nanoclusters for Scalable Electrosynthesis of Hydrogen Peroxide

Abstract Electrosynthesis of H 2 O 2 from oxygen reduction reaction via a two‐electron pathway is vital as an alternative for the energy‐intensive anthraquinone process. However, this process is largely hindered in neutral and alkaline conditions due to sluggish kinetics associated with the transformation of intermediate O 2 * into OOH* via proton‐coupled electron transfer sourced from slow water dissociation. Herein, we developed Pd sub‐nanoclusters on the nickel ditelluride nanosheets (Pd SNCs/NiTe 2 ) to enhance the performance of H 2 O 2 electrosynthesis. The newly‐developed Pd SNCs/NiTe 2 exhibited a H 2 O 2 selectivity of as high as 99 % and a positive shift of onset potential up to 0.81 V. Combined theoretical calculations and experimental studies (e.g., X‐ray absorption and attenuated total reflectance‐Fourier transform infrared spectra measurements) revealed that the Pd sub‐nanoclusters supported by NiTe 2 nanosheets efficiently reduced the energy barrier of water dissociation to generate more protons, facilitating the proton feeding kinetics. When used in a flow cell, Pd SNCs/NiTe 2 cathode efficiently produced H 2 O 2 with a maximum yield rate of 1.75 mmol h −1 cm −2 and a current efficiency of 95 % at 100 mA cm −2 . Further, an accumulated H 2 O 2 concentration of 1.43 mol L −1 was reached after 10 hours of continuous electrolysis, showing the potential for practical H 2 O 2 electrosynthesis.