Preparation Of Double-walled Na₂TiOSiO₄ Nanotubes Carrier And SCR Denitration Performance

NH3-SCR method is an effective method to denitration from NOx emissions from stationary sources. The development of high-performance SCR catalyst has become the key point of SCR technology. Na2TiOSiO4 with large specific surface area,strong adsorption ability, etc, can be used as hydrogen-absorbing material, but the application on the SCR has not yet been reported.In this paper, Na2TiOSiO4 nanotubes were synthesized by hydrothermal method with CTAB as assistant, and the effects of different molar ratios of TiO2 and SiO2,hydrothermal reaction temperature, hydrothermal reaction time, and morphology was investigated. After preparation of the sample, the morphology, specific surface area and composition of the products were characterized by TEM, BET, XRD, XPS, EDS,TG-DTA,29Si-NMR and so on. The results show that the Na2(TiO)SiO4 nanotube has a large specific surface area, a double-wall and the Q0 structure. The length of Na2(TiO)SiO4 nanotubes can be several hundred nanometers to 100 nm by simply adjusting the Si/Ti molar ratio from 1 to 3. Furthermore, the possible formation mechanism of Na2(TiO)SiO4 nanotube by CTAB assisted hydrothermal method was also proposed.The V2O5-WO3/Na2TiOSiO4 catalyst was prepared by impregnation. The content of V2O5 is lwt%, 3wt%, 5wt%, and the content of WO3 is 8%. The calcination temperature is 400 ?. The performance and characteristic of catalyst was analyzed by TPR, NH3-TPD, FTIR pyridine, XRD, BET and so on. And the denitration catalyst activity was tested, which investigate the impact of the load of V to acid magnitude of vanadium-based catalyst surface. The study found that Lewis acid sites and Br(?)nsted acid sites are decreased with increasing temperature. But at low temperatures Br(?)nsted acid sites decreased smaller than the decrease. 200 ? later dropped significantly,which prove the catalyst surface plays a major role at low temperatures is Br(?)nsted acid bit. And catalyst surface plays a major role is the Lewis acid sites at high temperature. In addition, the Lewis acid sites and Br(?)nsted acid sites content of 5wt% V2O5 supported catalyst are higher than lwt%, 3wt%. The catalytic activity is the best. It can prove the acid sites size and activity of the catalyst have some relation.Choose the best ratio of the catalyst and change the catalyst carrier. the V2O5-WO3/TiO2, V2O5-WO3/TiNT, V2O5-WO3/Na2TiOSiO4 catalyst was prepared.The performance and characteristic of catalyst was analyzed by NH3-TPD, FTIR pyridine, XRD, BET and so on. And the denitration catalyst activity was tested, which investigate the impact of different carriers to acid magnitude of vanadium-based catalyst surface. It can be seen that carrier acid content of Na2TiOSiO4 is maximum by pyridine infrared test. The crystallinity of catalyst V2O5-WO3/Na2TiOSiO4 is best by XRD. The V2O5-WO3/Na2TiOSiO4 catalyst activity is best. This may be explained by strong interaction between V2O5, WO3 and Na2TiOSiO4. Na2TiOSiO4 surface acid content is maximum, which leads to catalyst activity is best.