V2O5负载量对V2O5／TiO2催化剂SCR法脱硝的影响

以TiO2载体，采用浸渍法制备了不同V2O5负载量的用于选择性催化还原NOx的V2O5／TiO2催化剂。利用BET，SEM和Ⅺ①，对不同V2O5负载量的催化剂组成、结构、形貌和性能进行了表征，考察不同V2O5负载量对催化剂制备的影响。结果表明制备的催化剂具有较多的中孔和微孔，催化剂中V2O5含量的增加，会降低催化剂的表面积；V2O5含量为2％的V2O5／TiO2催化剂样品比表面积最大，但是其活性非常低；V2O5含量为4％催化剂比表面积较大，NOx脱转化率高；V2O5的负载量小时，V2O5主要以等轴聚合的钒基型式（V3O7和V6O13）存在，这些钒基是催化剂的活性中心；当负载量超过6％，V2O5主要以结晶相存在，占据大量活性位，降低催化效果。

Effect of V2O5 Loading to De-NOX of V2O5/TiO2 Catalysts

The V2O5/TiO2 catalysts used for selective catalytic reduction(SCR) of NOx with ammonia(NH3)were prepared by loading different amount(2 %、4 %、6 %、8 %) of V2O5 on the TiO2 particles by the impregnation method.The effect of V2O5 loading to preparation of catalyst was determined.Physical chemistry absorbance method(BET),Scanning Electron Microscope(SEM) and X-Ray Diffraction(XRD) were used to characterize the catalyst.The results showed that a certain percentage of micropores and mesopores exist in the catalysts investigated.The surface areas of catalyst were decreased as the increase of V2O5 loading.When the V2O5 loading was 2%,the surface area was the largest but the NO removal activity was very lower than others.When the V2O5 loading was increased to 4 %,the NO removal activity was higher than others.The impregnated V2O5 was well dispersed on the surface of TiO2,the type of vanadium oxide was V3O7 and V6O13 at the lower V2O5 loading.The V2O5 loading obtained to 6 %,the vanadium oxide was a cluster of crystalline particles which occupied the active site so as to decrease the NO removal activity.