Park, Cheolwoo Kwak, Hyelim Koh, Tae Sik Sohn, Yurim Park, Hyunwoong Gu, Geun Ho Moon, Gun-hee Kim, Wooyul 2026-01-13T07:00:36Z 2026-01-13T07:00:36Z 2026-01-12 2026-01 1433-7851 https://pubs.kist.re.kr/handle/201004/153984 Ammonia oxidation reaction (AOR) offers a promising carbon-free hydrogen production pathway under ambient conditions, yet practical implementation faces critical challenges from catalyst deactivation and competing side reactions in aqueous systems. We present an electrolyte-engineered approach to photoelectrochemical (PEC) AOR that enables both enhanced hydrogen production and reversible catalyst regeneration. By employing a non-aqueous acetonitrile electrolyte at the BiVO4 photoanode, we suppress competing oxygen evolution and NOx poisoning, achieving a 6.9-fold higher hydrogen yield than aqueous systems. Spectroscopic and electrochemical analyses reveal that catalyst deactivation in water is not permanent but dynamically reversible upon re-exposure to nonaqueous environment, emphasizing the solvent-governed interfacial behavior. This electrolyte-engineering approach proves broadly applicable across metal oxide photoanodes (BiVO4, WO3, α-Fe2O3), establishing a universal design principle for PEC AOR systems. Our findings redefine the role of electrolyte composition in governing interfacial pathways and provide a practical framework for developing high-efficiency ammonia-to-hydrogen conversion platforms with enhanced durability and flexibility. English John Wiley & Sons Ltd. Electrolyte-Engineered Photoelectrochemical Ammonia Oxidation Enabling Sustainable Hydrogen Production via Catalyst Regeneration Article 10.1002/anie.202522662 1 Angewandte Chemie International Edition, v.65, no.4 Angewandte Chemie International Edition 65 4 N scie 2-s2.0-105024716148 Chemistry, Multidisciplinary Chemistry Article; Early Access TOTAL-ENERGY CALCULATIONS REDUCTION LIQUID CO ACETONITRILE POTENTIALS PHOTOANODE HYDRAZINE EFFICIENT SPECTRUM Electrolyte Engineering Ammonia oxidation Deactivation Operando Spectroelectrochemistry Regeneration