The Preparation Of Catalyst With Graohene Loading On The Compound Of Ti-Cu-Mn And The Chatacteristic Of The Degradation On VOCs

Volatile organic compounds (VOCs) are one of the main atmospheric pollutants and harmful to environment. It is urgent to control VOCs. Catalytic combustion method is high efficiency, low energy consumption and no second pollutions. To seek a catalyst with low cost, high efficiency and stable is the hotspot study of catalytic combustion of VOCs. This study fixed Cu-Mn mixed-oxides and TiO2 to form a new ternary composite oxide as a catalyst active component by the chemical methods. We chose GS as the carrier because of its excellent carrier mobility, high specific surface area and good transparency. It would be conducive to the uniformly scattering of oxide active phase and be expected to gain a high-performance and highly active catalyst. It was widely used in the light catalytic, but not widely used in the catalytic combustion. A series of titanium, copper and manganese oxide catalysts were made by hydrothermal precipitation in this project. Using the catalytic combustion of toluene and xylene, the project studied the catalytic performance of catalyst and combined with a variety of characterization methods to analyze the structure of the catalytic performance and discussed the catalytic mechanism. The main research results are as follows:(1) The carrier (graphene) was made by the Hummers and hydrazine hydrate method, and the Ti-Cu-Mn was loaded by hydrothermal method. The activity evaluation experimental results show that Ti-Cu-Mn/GS (1:1:1) has better performances of benzene series degradation in the catalysts. During the T50 of the catalyst in the process of catalytic oxidation of toluene, xylene is 53 ℃ and 97 ℃ respectively. What’s more, the catalyst Ti-Cu-Mn/GS (1:1:1) is the suitable catalyst for degradation of toluene and xylene.(2) By the characterization methods, such as BET, XRD, TEM, SEM and XPS, the results show that Ti-Cu-Mn/GS (1:1:1) has the better catalytic with the best inhibitor dispersing effect, and has larger specific surface area. However, increasing the proportion of Cu-Mn mixed oxides may cause the loss of catalyst performance. And the major oxidation active substances in catalyst are Cu, Mn and Ti. Besides they are respectively formed as CuMnO4 and TiO2. The increase of the titanium may make originally activity stronger, and keeping the catalyst with high benzene degradation rate under the condition of low temperature. At the same time, it may maintain the stability of the catalyst.(3)The degradation efficiency of toluene and xylene for Ti-Cu-Mn/GS (1:1:1) will decrease with increasing of the benzene series concentration and the gas humidity. But it will decrease or keep changeless with increasing of the superficial velocity. The results show that the best environment of catalytic oxidation is the concentration of benzene series 5000mg/m3, low humidity (5%), medium (20-40%) of the oxygen content.(4) Through the study of the catalytic oxidation reaction kinetics equation and reaction intermediate products, the results show "that the catalytic reaction is first order reaction. When the greater the concentration of toluene and xylene are, the fewer the degradation rates are, the smaller the reaction constant are. When we found the mechanism in the catalytic reaction, It found that the reaction intermediate products of toluene catalytic oxidation are benzene, benzoic acid and benzyl alcohol. And benzoic. acid should open the ring of benzene at high temperature, and formed fatty acids. Because of its high activity, it would completely oxidized to CO2 and H2O under the condition of sufficient oxygen.