不同方法负载钨钒钛催化剂对催化氧化邻二氯苯的影响

Influence of different loading methods of V_2O_5/WO_3/TiO_2 catalysts on total catalytic oxidation of o-dichlorobenzene

钨钒钛催化剂是消除钢铁冶炼废气中的二噁英最好的催化剂,为了降低工业生产成本,并获得良好的催化效果,将实验室筛选出的钨钒钛催化剂负载到不同载体上,研究催化剂负载量及不同负载方法对降解邻二氯苯催化效率的影响。采用溶胶-凝胶-浸渍法和直接浸渍法在堇青石蜂窝陶瓷上负载V_2O_5/WO_3/TiO_2催化剂,用X射线衍射、扫描电镜和X射线能量色散谱对制备的催化剂进行表征,结果表明,直接浸渍法在堇青石蜂窝陶瓷上负载的V_2O_5/WO_3/TiO_2催化剂含量比溶胶-凝胶-浸渍法负载的含量高,粒度较小,表面光滑无缝隙,活性成分V和W分散较好,催化活性高,在(250～350)℃邻二氯苯去除率大于95%,直接浸渍法负载的催化剂与堇青石的最佳质量比为1:100。

V2O5/WO3/TiO2 catalysts are one of the best catalysts for eliminating dioxin in flue gas from a steel-smelting furnace.In order to reduce the production cost and obtain the good catalytic properties,the effects of supported catalyst dosage and different loading methods on total catalytic oxidation of o-dichlorobenzene were investigated.Integral V2O5/WO3/TiO2 catalysts supported on cordierite were prepared by sol-gel-impregnation and direct impregnation methods and characterized by XRD,SEM and EDS.The results showed that the catalyst prepared by direct impregnation method had higher V2O5/WO3/TiO2 content,smaller particle size and exhibited higher catalytic properties than that by sol-gel- impregnation method.Active ingredients V and W were dispersed better and the catalyst surface was smooth and had no cracks.The conversion rate of o-dichlorobenzene was over 95% at （250-350） ℃.The optimal mass ratio of the catalyst to cordierite supported by direct impregnation method was 1∶100.