The Catalysts Of Mesoporous Metal Oxides: Preparation, Characterization And Catalytic Behavior For VOCs Oxidation

Volatile Organic compound （VOCs） comes from industrial production, Catalyticcombustion is not only an effective method for the remove of VOCs, but also the method cannot produce secondary pollution in the remove process. The catalysts play a very importantrole in the catalytic oxidation system, the catalyst system for remove VOCs is generallyincluding active component and support.A series of hierarchical porous titania materials doped with different contents of Cerium（Ce-TiO₂） were synthesized by utilizing the oil-in-water （O/W） emulsion technique and usedas a substrate for Pd. The techniques, such as, X-ray diffraction （XRD）, N2adsorption-desorption, scanning electron microscopy （SEM）, UV-vis diffuse reflectance spectra（DRS）and H₂Temperature-programmed reduction （H₂-TPR） are used for characterization ofcatalysts and supports. The catalytic properties of0.5%Pd/Ce-x-TiO₂for total oxidation ofpropane were evaluated using a microreactor-GC system. The results showed that0.5%Pd/Ce-x-TiO₂have higher activity for propane oxidation. The catalytic behaviordepended on the amount of Ce-doped, the surface area and pore size. The catalyst with2%of Ce molar content exhibited the highest catalytic activity.A series of Ce1-xMnxO₂mesoporous materials with high-surface area, uniform pore-sizedistribution and strong thermal stability were prepared by a surfactant-assisted method.Those materials were used as a supporter for loading CuO as well. The catalytic properties ofcatalysts were evaluated by propane oxidation using a microreactor-GC system. Theincorporation of manganese ions into CeO₂could form solid solution with cubic fluoritestructure, it can improve the oxygen transfer capacity, i.e., improving the activity of thecatalyst for propane oxidation. In addition, a synergism between the supports and CuOlikewise increased catalytic activity. The optimization studies show that the catalystcalcinated at400°C with the molor ratio of Ce/Mn=3/2have the highest activity for propaneoxidation. A series of10%Co₃O₄/β-SiC and10%Co₃O₄/SiC-TiC catalysts was prepared themethod of wet impregnation. The catalytic properties were evaluated by propane oxidationusing a microreactor-GC system and10%Co₃O₄/β-SiC have higher activity for propaneoxidation.