Study On The Preparation Of Nano TiO₂and Their Application In The Multi-phase Catalytic Reactions

Titanium dioxide nano-materials used in heterogeneous catalysis system possessthe advantages: large surface area and pore volume, excellent photo-electro-chemicaleffect, as well as the strong ability of oxidation. Thus, it can greatly enhance theprocessof heterogeneous catalysis and be used in various heterogeneous catalysissystems，represented by photocatalytic degradation of organic pollutants, car exhausttreatment and carbon monoxide methanation reaction, etc. This study focuses on thecatalytic performance of titanium dioxide nano-materials in these three typicalheterogeneous catalysis systems.First, titania nanotube materials was prepared by using hydrothermal synthesismethod. It was found that the morphology and crystal structure of TiO2hydrothermalproduct significantly depend on their hydrothermal synthesis temperature. Theoptimal hydrothermal synthesis temperature for the formation of TiO2nanotubeslocates in120~150°C range. Washing step using acid solution in low concentrationwill decrease the reunion of nanotubes, enhance the dispersion of the nanotubes, andkeep the nanotubularmorphology, compared with deionized water washing. TiO2nanotubular materials calcined at300~400°C prosess anatase phase. Nanotubes withhigh surface area and pore volume obtained at120~150°C possess higheradsorption capacities and photo-activity. Moreover, the mechanism of photocatalyticdegradation of MB on TiO2nanotubes was discussed.Secondly, TiO2nano-materials were used as catalyst carrier and photocatalyst.CuO/CeO2-TiO2catalyst was prepared by continuous impregnation method, theircatalytic performance on the NO+CO redox reaction and relative mechanism werestudied. It is showed that the electronic state interaction between Ce and other twocomponents (Ti and Cu) in the catalysts induced relative flexible oxygen transportfrom ceria to copper species and the high oxygen vacancy concentration, resulting inthe high catalytic activity for NO and CO reaction.Finally, ZrO2-TiO2supports with different Zr content were prepared byimpregnation method and co-precipitation method, respectively. The effect ofpreparation methods and ZrO2content on the methane yield and the selectivemethanation reaction as well as the related mechanism will be elementarily explored.