负载量与SO4^2-对V2O5／TiO2催化氨氧化3-甲基吡啶反应的影响

以2种商品化的TiO2为载体，用浸渍法制备了一系列V2O5负载量不同的V2O5／TiO2催化剂，通过X射线衍射表征了V2O5在载体TiO2表面的分散情况，考察了催化剂对3-甲基吡啶气相氨氧化合成3-氰基吡啶反应的催化性能、结果表明，钒氧物种在TiO2载体表面呈高度分散时V2O5／TiO2催化剂表现出更优的催化性能，其中以Sigma公司生产TiO2为载体制备的5％V2O5／TiO2催化剂的性能最优，对应93％的3-甲基吡啶转化率和90％的3-氰基吡啶选择性；载体中含硫酸盐会降低催化剂催化活性。

Effects of loadings and SO4^2- on the catalytic properties of V2O5/TiO2 for ammoxidation of 3-Picoline

Two commercial anatase TiO2 supports were used to prepare a series of V2O5/TiO2 catalysts with various V2O5 loadings by wet impregnation, and their catalytic performances on gas-phase ammoxidation of 3-picoline to nicotinonitrile were investigated in a house-made fixed-bed reactor. The dispersion of V2O5 on the ana- tase TiO2 supports was characterized by XRD. The results indicated highly dispersed V2O5 on both TiO2 supports, corresponding to the best catalytic performance on gas-phase ammoxidation of 3-picoline to nicotinonitrile. In the case of 5% V2O5/TiO2 （Sigma） catalyst, the selectivity for nicotinonitrile was 90% and the conversion of 3-picoline was 93%. Sulfate doped on TiO2 （Shanpu） could dramatically reduce the activities of the corresponding catalysts.