Catalytic Co-oxidation of Dichloromethane and non-chlorinated VOC over HxPO4-RuOx/CeO2, Pt/HZSM-5 and dry-mixed Ru-Pt Catalysts

Industrial flue gases contain chlorinated VOCs (CVOCs) and hydrocarbons, along with various contaminants. Although previous studies have primarily focused on the catalytic oxidation of individual VOCs, the activity of VOCs in mixtures often differs from that of individual compounds. The catalytic oxidation of dichloromethane in the presence of a second VOC (ethyl acetate, n-hexane, and toluene) was investigated using HxPO4-RuOx/CeO2, Pt/HZSM-5, and dry-mixed Pt-Ru catalysts. The dry-mixed catalyst combines the excellent dechlorination ability of HxPO4-RuOx/CeO2 with the oxidation capability of Pt/HZSM-5. A mixture of 1000 ppm toluene and 100 ppm dichloromethane is fully oxidized over the Ru-Pt catalyst at 300 degrees C, 30 degrees C lower than the T 100 observed on the other two catalysts. DFT calculation reveals that the activation of toluene and dichloromethane occurs on Pt and Ru sites, respectively, dechlorinated by proton of phosphate. Furthermore, by-product dioxin content on Pt-Ru is significantly below 0.1 ng TEQ Nm-3 limit.