Deep Oxidation Removal of Nitric Oxide and SO₂ via Singlet Oxygen and Hydroxyl Radicals in the LaCoO3-δ/H₂O₂ System

This study proposes a novel LaCoO3-δ/H2O2 Fenton-like process for the efficient generation of nonradical singlet oxygen (1O2) and hydroxyl radicals (•OH), enabling the deep oxidation of nitric oxide (NO), as well as simultaneous denitrification and desulfurization. A LaCoO3-δ perovskite material enriched with Co3+ ions and oxygen vacancies (OV) was successfully synthesized by using a one-step citric acid sol–gel method. OV enhances electron mobility and expedites the redox cycling of surface Co2+/Co3+ pairs, thereby promoting the generation of •OH and •O2–. The high Co3+ content further facilitates the transformation of •O2– into 1O2. Moreover, electron-rich centers and highly reactive lattice oxygen (O2–) induced by abundant OV also contribute to the activation of H2O2, enhancing the production of •OH and 1O2. When combined with a comprehensive Na2SO3/NaOH absorption system, simultaneous removal efficiencies of 91.2% for NO and 100% for SO2 were achieved under optimal experimental conditions while ensuring good operational stability. This innovative noniron-based Fenton-like system not only rivals the performance of typical iron-based Fenton-like systems but also provides new insights into the development of multipollutant deep oxidation removal technologies for application in coal-fired power plants.