论文部分内容阅读
用TMEDA-Na_2O-Al_2O_3-SiO_2-H_2O体系的水热结晶合成了硅铝比相同的ZSM_(-5),ZSM_(-35)和Md沸石,并用SEM,XRD和IR等方法对它们进行了表征。由于它们的骨架结构不同,用氨TPD法测量得到的氢型样品的表面酸中心强度和数量有明显的差别,其酸强度次序为HMd>HZSM_(-35)>HZSM_(-5),酸中心数量次序为HZSM_(-35)>HMd>MHZSM_(-5),用微反装置测量了它们的裂解、异构化和歧化反应的催化活性,并讨论了上述反应中沸石表面酸性和骨架结构对催化活性和选择性的影响。
ZSM_ (-5), ZSM_ (- 35) and Md zeolites with the same Si / Al ratio were synthesized by hydrothermal crystallization from TMEDA-Na 2 O-Al 2 O 3 -SiO 2 -H 2 O system and characterized by SEM, XRD and IR . Due to their different frameworks, the surface acid sites of the hydrogen-type samples measured by the ammonia TPD method show obvious differences in the intensity and the number of acid sites. The order of the acid sites is HMd> HZSM_ (35)> HZSM_ (- 5) The order of their numbers was HZSM_ (35)> HMd> MHZSM_ (- 5). The catalytic activities of their pyrolysis, isomerization and disproportionation reactions were measured by a micro-reactor. The effects of zeolite surface acidity and framework structure Effect of catalytic activity and selectivity.