Catalytic Combustion Of VOCs Over Non-Precious Metal Mixed Oxides Catalysts Supported On Cordierite Honeycomb

VOCs are one of the main sources of air pollution. Among current technologies on VOCs control, catalytic combustion technology has been regarded as the most effective one due to its simple equipments and relatively low temperature requirement in eliminating VOCs. In order to conquer the disadvantages of conventional Al₂O₃ washcoat with complex preparation and high cost, this study aims to develop a environment-friendly preparation method with sample technics. The catalysts were characterized by XRD, TPR techniques. The catalytic activity for toluene was evaluated by catalytic combustion equipment and Gas Chromatography as detecting method.This study explores Cu-Mn mixed oxides supported on cordierite prepared by an impregnation method and the effects of the catalytic property on preparation and cocatalyst of Ag and K. The results show that the formation of a proper amount of Mn₂O₃ is favorable to increasing catalytic activity, of which with the loadings of 2% Cu and 8% Mn the catalyst has the highest activity for the direct deposited preparation. As a part of Mn replaced by Ag, the catalytic activity and the thermal stabilization are both remarkably improved and the catalytic activity is the highest for the catalyst of Cu(2%)-Mn(6%)-Ag(2%): toluene has been completely oxidized when the reaction temperature is 220℃. And the catalyst has excellent adhesion ability associated to the cordierite honeycomb. Moreover, the catalyst prepared by environment-friendly method holds the similar catalytic property to that prepared by direct depositing method.A series of La-Mn composite oxides catalysts were prepared by an impregnation method. The effects of calcined temperature and addition of Ce, Pr, K, Na or Cu elements on the complete combustion of toluene are investigated. The results show that the LaMnO₃/Cord catalyst calcined at 800℃exhibits high catalytic performance. It is also found that the addition of Ce to LaMnO₃/Cord catalyst was favourable for the improvement of complete combustion of toluene, and the catalyst exhibits the highest catalytic property when the conversion of toluene was higher than 97% at the reaction temperature of 260℃, where the Ce/La molar ratio in the catalyst was 1 : 1.