Simultaneous removal of SO2 and NO from flue gas with OH from the catalytic decomposition of gas-phase H2O2 over solid-phase Fe2(SO4)3

•OH from the decomposition of gas-phase H2O2 over solid Fe2(SO4)3 is verified.•99.8% SO2 and 92.5% NO removal efficiency is obtained.•The improvement of SO2 on OH generation is investigated by XPS approach.•The change of catalysts in a longtime running is studied.

In typical Fenton-like reaction, ferric sulfate (Fe2(SO4)3) was usually used to produce hydroxyl radical (OH) in the form of Fe3+ in aqueous solution. In this research, it was the first time that OH was obtained from the catalytic decomposition of gas-phase H2O2 over solid-phase Fe2(SO4)3 for simultaneous removal of SO2 and NO. The radical scavenger tests indicated the critical role of OH in NO removal rather than SO2 removal. The operation parameters were systematically investigated. The SO2 removal efficiency was affected by the liquid absorption, whereas the NO removal was mainly affected by the catalytic temperature, H2O2 concentration, H2O concentration and catalyst dosage. 99.8% SO2 and 92.5% NO were achieved under the operation condition where the molar ratio of H2O2 to NO was 2.5. According to the products before and after scrubbing, the removal process of SO2 and NO were speculated. NO removal experiments in NO only system and simultaneous removal system was studied, respectively. The improvement of SO2 on NO removal was elucidated by XPS characterization. SO2 and NO removal efficiencies in 12 hours' test were collected and the evolution of catalyst before and after reaction was studied using FTIR and SEM-EDX.

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