FT-IR study of the catalytic oxidation of SO₂ during the process of selective catalytic reduction of NO with NH₃ over commercial catalysts

This work briefly reveals the process of catalytic oxidation of SO₂ and the influences of NH₃, NO and O₂ on the oxidation behavior based on FT-IR.It suggests that the process of oxidation of SO₂: the absorption of SO₂ on V₂O₅ sites occupying its O atom in the form of SO^2-₃; reaction between absorbed SO₂ and O atom in V⁵⁺-OH to form an VOSO₄-like structure;reoxidation of V⁴⁺ to V⁵⁺ by O₂,promoting the transformation from VOSO₄-like intermediate to SO₃ and V₂O₅. NH₃ and NO competitively absorb with SO₂,suppressing its oxidation behavior. The removal of NOx and the oxidation of SO₂ is the relationship of mutual inhibition.