| In recent years, with the rapid development of industry and economy, a lot of fuel combustion and vehicle exhaust more nitrogen oxides and thus induce severe harm. Nitrogen oxides(NOx) are one of the main pollutants in acid rain, ozone depletion and photochemical smog, and have a lot of harm on the natural environment and human health. When it comes to the removal of nitrogen oxides, the most widely studied and most promising technology is selective catalytic reduction(NH3-SCR) technology. The core technology of NH3-SCR is the catalyst, the most widely used catalyst is the V2O5-WO3/TiO2 system. Although V2O5-WO3/TiO2 catalyst shows high activity, but the disadvantages of such catalyst are that the reaction temperature and costs are high and the active component vanadium oxides are toxic. Aluminum red mud is an industrial waste, the environmental pollution problems can not be ignored for red mud having a strong alkaline. Red mud contains a lot of iron oxide, alumina, silica, titania and other metal oxides components, which has promoting effection of denitration: wherein the iron oxide has good catalytic denitration activity, aluminum and silicon oxides are widely studied carrier for denitration catalyst. Therefore, using red mud for the preparation of denitration catalyst on is feasible and meaningful. However, red mud contains a lot of basic components Na, Ca, etc., hinder its industrial application, it is also necessary to make sure the red mud pretreatment before achieving its catalytic DeNOx applications.In this thesis, we use aluminum industrial waste red mud as raw material. Red mud is firstly pretreated and then supported with metal oxide active component, thus a series of red mud denitration catalyst is prepared. The phase of red mud is confirmed by X-ray powder diffraction(XRD), the results show the main species of red mud are Fe2O3, SiO2, TiO2, Al(OH)3 and other species. X-ray fluorescence(XRF) results confirm that red mud contains large amounts of Fe, Al, Si and other oxides. The pretreatment process not only reduces the alkali content of the red mud, but also improves the specific surface area, improve the pore structure and improve denitration activity of red mud. The pretreatment process of red mud is simple and economical, activated red mud in catalysis has good application prospects. After the loading different metal oxide component onto pretreated red mud, the evaluation results show that V and Cu oxides have a higher denitration activity compared with Mo, Co, Ni oxide. The effect of different loading amount is investigated and results show that with the increase of the active ingredient amount, the denitration catalyst performance at first increased and then decreased. This trend shows that it exsits an optimal duty ratio of the active component on the surface of red mud, the ratio may differ with the carrier and active component. The catalysts are characterized by specific surface area analyzer, scanning electron microscopy(SEM), X-ray diffraction(XRD) characterization techniques. The redox properties of samples are tested by H2 temperature-programmed reduction technology. The mechanisim and structure-fuctional relationship are measured by NO-TPD and in situ infrared analyzes. The above performance test results show that 7Cu/PTRM catalysts have optimum performance, appear to show the best catalytic activity of the experimental conditions. |
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