F对NiO－WO_3／F－Al_2O_3－SiO_2催化剂物化性质的影响

The Influence of Fluoride Content on the Characteristics of Ni W/Al 2O 3 SiO 2 Catalysts

以一系列不同Ｆ含量的双功能催化剂为研究对象，采用ＴＰＤ、ＢＥＴ、ＤＴＡ及孔径分布测定等方法，对催化剂的物化性质进行了表征，采用色谱－微反联合装置考查了Ｆ对该催化剂加氢裂化活性的影响。结果表明，Ｆ的引入可以有效地调节催化剂的宏观结构，致使催化剂内微孔聚并，引起催化剂比表面积下降；同时，Ｆ的引入还引起催化剂总酸度下降。并对可能的原因进行了分析。另外，当Ｆ离子含量为１．５１％和２．３６％时。

In this paper,a series of Ni W/F Al 2O 3 SiO 2 catalysts containing constant WO 3 and NiO loadings (38.3%,12.3%) and various amounts of F(0.24% 3.76%),introduced after the deposition of the W and Ni are characterized using TPD,BET,DTA and pore volume distribution measurements.The results are correlated with the activities for the hydrogenation of toluene and the hydrocracking of n heptane,which are performed at 400℃,6.0MPa and 1.0h -1 liquid space velocity using a fixed bed micro reactor.As the concentration of F increases,the specific surface area and the acidity decrease markedly.The decrease in specific surface area can be partly attributed to the breaking of the inner walls of the relative narrow pores and creation of larger ones.The variation in the acidity is a result of co action of variation in the catalyst texture and the inductive effect of F.