Simultaneous removal of SO2 and NO from flue gas using iron-containing polyoxometalates as heterogeneous catalyst in UV-Fenton-like process

The simultaneous removal of SO2 and NO from flue gas was firstly carried out by heterogeneous UV-Fenton-like process using Iron-containing polyoxometalates complex (denoted as Fe(III)AspPW) as catalyst. The results showed that SO2 achieved complete removal under all experimental conditions. The simultaneous removal efficiencies of 100% for SO2 and 84.27% for NO were obtained under the established optimal experimental conditions. The main reaction products were identified as nitrate and sulfate based on the characterization of ion chromatography (IC) and material balance summary. Especially, the physicochemical properties of the fresh and spent catalyst were characterized systematically by a series of techniques, which manifested the stability of the catalyst and the existence of redox pair Fe3+/Fe2+ during the catalytic process. In combination with correlative references, the reaction mechanism was proposed, which stemmed from the chemisorption of H2O2 by hydrogen bonding and the synergetic effect between the Fenton-like catalysis of ferric iron and photo-catalysis of PW12O403- occurred on the surface of Fe(III)AspPW.