Preparation And Characterizations Of Copper Oxide Catalysts For Gaseous Phase Dioxin-like Pollutants Degradation

Dioxin-like Chlorine Persistent Organic Pollutants(Cl-POPs) are highly toxic gaseous phase of environmental pollutants. Catalytic combustion method is one of the most thoroughly methods for Cl-POPs Control. V-Cu catalyst and (Fe,Co,Cu,V)-Mn/cordierite catalysts were produced in order to choose high efficiency and stable catalysts for Cl-POPs catalytic combustion. Catalytic performance was evaluated with o-dichlorobenzene(o-DBC) as the model compound of dioxin. Catalytic performance of V-Cu/TiO2catalyst that was prepared by hydrothermal method and sol-gel method respectively was investigated. The results showed that V-Cu/TiO2catalyst prepared by sol-gel method presented high catalytic activity for degradation of o-DBC at400℃. The influences of calcining temperature and ratio of vanadium and copper on the catalytic degradation of o-DBC were studied. The structure and morphology of catalyst were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy Disperse Spectroscopy (SEM-EDS), Program Temperature Reduction (TPR), Nitrogen Physical Adsorption (BET) and other technical methods. XRD results revealed that V-Cu/TiO2catalyst was mainly composed of anatase-TiO2and rutile-TiO2, and the crystalling phase of TiO2was gradually transformed from anatase-TiO2to rutile-TiO2with the calcining temperature increasing. In addition, it was found that the catalyst mainly composed of anatase-TiO2displayed a high efficiency for degradation of o-DBC. TPR results further demonstrated that the reduction reaction of V-Cu/TiO2catalyst, which was prepared by sol-gel method at the calcination temperature of300℃, is easy to occur at the low temperature. BET results showed that V-Cu/TiO2catalyst, which was prepared by sol-gel method with ratio of vanadium and copper1:4at the calcining temperature of300℃, had the largest surface area. The above results demonstrated that vanadium and copper were dispersed well on the surface of anatase-TiO2, which lead to an improvement catalytic activity for degradation of o-DBC.(Fe,Co,Cu,V)-Mn catalysts supported on cordierite were prepared by co-precipitation method. The results showed that Cu-Mn/cordierite catalyst had the best performance in o-DCB elimination. In order to improve its catalytic activity, the conditions optimization experiments of Cu-Mn/cordierite catalyst were further studied. The influences of method, calcining temperature, ratio on the catalytic activity of Cu-Mn/cordierite catalyst were researched. XRD results showed that the CuMn2O4spinel phase can generate after Cu-Mn/cordierite catalyst was calcinated. SEM results demonstrated that the particle of Cu-Mn/cordierite is well dispersed which can be helpful for the catalytic combustion reaction. EDS results indicated that catalyst after reaction had a small amount of residual chlorine on its surface compared with before reaction. Stability test indicated that catalytic activity was about65%after20h continued reaction, which showed that Cu-Mn/cordierite catalyst had high catalytic activity at low temperature. From the above results, it can be concluded that Cu-Mn/cordierite has a good application prospect in the process of catalytic combustion Cl-POPs.