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采用共沉淀法制备TiO_2-SnO_2固溶体,浸渍法负载WO_3和V_2O_5得到一系列V_2O_5-(x%)WO_3/TiO_2-SnO_2脱硝催化剂。利用比表面积测定(BET)、X射线衍射(XRD)、原位漫反射傅里叶变换红外光谱(in situ DRIFTS)、程序升温脱附(NH_3-TPD)、高分辨率透射电子显微镜(HRTEM)等表征技术,结合脱硝性能测试,研究催化剂的表面特性、微观结构及脱硝活性。结果表明:V_2O_5-12%WO_3/TiO_2-SnO_2催化剂在250~400℃的温度窗口具有95%的NO_x转换率;随着WO_3负载量增加,催化剂比表面积有所减小;WO_3以无定形态存在于催化剂表面;催化剂表面Br?nsted酸中心强度随WO_3负载量增加逐渐增大,这是V_2O_5-(12%)WO_3/TiO_2-SnO_2催化剂具有最佳脱硝活性的主要原因。
The TiO_2-SnO_2 solid solution was prepared by co-precipitation method, and a series of V_2O_5- (x%) WO_3 / TiO_2-SnO_2 denitrification catalysts were obtained by impregnation of WO_3 and V_2O_5 by impregnation method. (BET), X-ray diffraction (XRD), in situ DRIFTS, NH_3-TPD, HRTEM, And other characterization techniques, combined with the denitration performance test to study the catalyst surface properties, microstructure and denitration activity. The results showed that the V_2O_5-12% WO_3 / TiO_2-SnO_2 catalyst had a NO_x conversion rate of 95% at a temperature of 250 ~ 400 ℃. With the increase of WO_3 loading, the specific surface area of the catalyst decreased. WO_3 was present in an amorphous state On the catalyst surface, the intensity of Brönsted acid sites on the catalyst surface gradually increases with the increase of WO3 loading, which is the main reason for the optimal denitrification activity of the catalyst of V_2O_5- (12%) WO_3 / TiO_2-SnO_2.