| NOx is one of the main air pollutants.It is also the main precursor of forming photochemistry fog.It has been a hotspot in the international environmental field to control and treat NOx pollution.Due to high efficiency,selection and economic value,Selective catalytic reduction(SCR)is the major technology for treating NOx emissions from power plant.The catalyst is the key problem of SCR technology,and the research of support material is the key of SCR catalyst.Because of it's high BET surface area and high thermal stability,the TiO2-SiO2 mixed oxides was seemed as excellent support material.In this paper,The Porous TiO2-SiO2 mixed oxides was made by co-precipitaition method.The active composition was loaded by impregnation method to make V2O5-WO3/TiO2-SiO2 catalyst.Base on various catalyst characterization method to sample and catalytic performance testing,the results showed that:the mixed oxides were porous structure,the pore volume and surface areas increased with the increase of Si contents.The spheroidal particle of TiO2 and SiO2 were arranged in order to form "tunnel" pore of materials.The materials with a Ti/Si atomic ratio of 4/1 showed the smallest pore size(5.1nm)and the narrowest pore size distribution.The FT-IR and surface element analysis indicated that the formation of Ti-O-Si linkages in the mixed oxides and the enrichment of Ti element on the surface,that the dispersedness level of V2O5 on the surface of TiO2 was very high,when the V2O5 loading was 3.0wt%,the formation of V species are monomers,It was exhibited the greatest activity,NO conversion was more than 90%when the temperature was between 280℃～450℃.The catalyst had high adaptability for different NO concentration.De-NO technics which use this catalyst should control NH3/NO between 0.8～1.Reaction kinetics of catalysts was studied.And the results indicated that SCR of NO over V2O5-WO3/TiO2-SiO2 catalyst accorded with EleyRideal mechanism and belonged to first-order reaction.
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