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采用程序升温热脱附(TPD)及脉冲催化色谱法研究不同 SiO_2/Al_2O_3比和用不同模板剂合成的几种 HZSM-5沸石的酸性、催化活性以及它们之间的关系。考察了不同酸中心的性质以及对正己烷裂化活性的贡献。沸石的酸性和正己烷裂化活性取决于沸石本身所含铝原子数,其酸性和活性随 HZSM-5沸石 SiO_2/Al_2O_3比增加而下降。HZSM-5沸石存在着两种不同类型的酸中心,其酸强度也不相同,但对正己烷裂化活性有贡献的仅仅是强酸中心。用不同模板剂合成的 HZSM-5沸石其酸性和活性也有很大差别。
The acidity and catalytic activity of several HZSM-5 zeolites synthesized by different SiO 2 / Al 2 O 3 ratios and different templating agents were studied by temperature programmed desorption (TPD) and pulse catalytic spectroscopy. The nature of the different acid sites and their contribution to the n-hexane cracking activity were investigated. The acidity and n-hexane cracking activity of the zeolite depend on the number of aluminum atoms contained in the zeolite itself, and its acidity and activity decrease as the SiO 2 / Al 2 O 3 ratio of the HZSM-5 zeolite increases. There are two different types of acid centers for HZSM-5 zeolites, and their acid strengths are also different, but only the strong acid centers contribute to the n-hexane cracking activity. HZSM-5 zeolites synthesized from different templates also have very different acidity and activity.