Preparation of V_2O_5-WO_3/TiO_2-SiO_2 Catalyst for Selective Catalytic Reduction of NO by NH_3

Using titanyl sulfate and silica sol as raw materials,the TiO2-SiO2 mixed oxides (Ti/Si = 1:1 atom) with high specific surface area was prepared by coprecipitation method. Then,the prepared TiO2-SiO2 mixed oxides were used as the support to prepare the V2O5-WO3/TiO2-SiO2 catalyst by the impregnation method,and the catalytic behavior of the prepared catalyst used for the selective catalytic reduction (SCR) of NO by NH3 was investigated. The results show that the TiO2-SiO2 mixed oxides has high spesific surface area and many turnnel holes,which results in the better distribution of active element Ti on the surface of the TiO2-SiO2 mixed oxides. Comparing with the catalyst with the support of pure TiO2,the V2O5-WO3/TiO2-SiO2 catalyst shows better activity temperature window and stronger surface acidity,which would promote the adsorption capability of NH3 on the surface of the catalyst. Using the prepared catalyst,the conversion ratio of NO can be up to 98% at the temperature range between 280℃ and 380℃,and even under low NH3/NO molar ratio (0.8～1.0 mol?mol?1),the V2O5-WO3/TiO2-SiO2 catalyst still shows good catalytic activity for reduction of NO with NH3.