Preparation And NO_x Conversion Performance Of CuTi Selective Catalytic Reduction Catalyst

NOx pollution has serious harm to human body and environment,the current mature catalyst is V2O5-WO3/TiO2,while V is toxic and the reaction temperature is higher.The metal oxide catalyst has low sulfur resistance,and the metal skeleton of the molecular sieve catalyst is easy to collapse.LDHs have potential applications because of their controllable ions and their catalytic properties.In this paper,a low temperature NH3-SCR catalyst based on LDHs was successfully synthesized by homogeneous decomposition co-precipitation method.In addition,the traditional impregnation CuO/Ti02 catalyst was synthesized for comparison.The effects of reaction temperature,calcination temperature and metal ratio on the catalytic performance of the catalyst were measured by NOx analyzer.The catalyst efficiency can reach to 88.9%under the condition of 200? with the ratio of Cu/Ti to 1:1.The Cu-Ti LDHs catalyst also has a certain thermal stability and has performance well at 400? and 500 ?.X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(HR-TEM),nitrogen adsorption desorption(BET)were used to characterize the material,results showed that urea decomposition can be successfully synthesized Cu-Ti LDHs and the catalyst has smaller particle size and higher surface area(150.5 m2/g).The ammonia temperature programmed desorption and hydrogen temperature programmed reduction were used to research the reaction mechanism.At the same acid site,CuiTiOx is more acidic than CuO/TiO2,which is in agreement with the conversion rate of NOx.And the hydrogen consumption of CulTiOx in the low temperature range is 6.147 mL,Cu3TiOx is about 3.647 mL,Cuo.5TiOx is 3.354 mL and the traditional CuO/TiO2 is only 0.274 mL.This data is in good agreement with the catalytic performance of the catalyst in the NH3-SCR reaction at low temperature,and it is proved that the NH3-SCR catalyst prepared by LDHs has potential superiority.In addition,the copper titanium catalysts based on LDHs has good sulfur resistance.To sum up,the low temperature NH3-SCR catalyst based on LDHs has good application prospect.After the performance evaluation of CuTi catalyst,the monolithic catalyst was prepared by using cordierite.The preparation process was studied and its application was tested.The effects of codierite amouts,gas flow and coating times on the application performance of catalyst were preliminarily explored.