Chloride‐Mediated Photoelectrochemical Selective Oxidation of Polyols Coupled With Hydrogen Evolution

ABSTRACT Photoelectrochemical (PEC) water splitting coupled with the oxidation of polyols into high‐value‐added chemicals is of practical significance for the upgrading of biomass and polyester plastics. However, the current polyols selective oxidation reactions suffer from harsh reaction conditions (strong basic electrolyte) and high costs of noble metal‐based catalyst via the reactive oxygen species‐mediated pathway. Herein, we for the first time demonstrate a chlorine radicals‐mediated route toward polyols oxidation under neutral conditions. As proof‐of‐concept, NiCo‐LDH‐decorated TiO 2 has been developed to promote the oxidation of ethylene glycol (EG) to glycolic acid (GA), achieving a GA production rate of 8.7 µmol cm ‒2 h ‒1 with a selectivity of 76.2% in NaCl electrolyte under irradiation, which is the highest value reported to date in PEC system. Mechanistic studies reveal that the key chlorine radicals facilitate C─H bond cleavage to form chlorinated intermediates for GA production. Additionally, we successfully coupled PEC PET‐derived EG valorization with H 2 generation from seawater, attaining GA and H 2 productivity of 30.6 and 93.9 µmol cm ‒2 , respectively. This work offers a novel perspective on polyols oxidation reaction pathway modulation and demonstrates a solar‐to‐chemical conversion approach for integrating low‐value carbon sources recycling and PEC synthesis.