超细HZSM-5分子筛硅/铝比对其催化甲醇制丙烯反应的影响

 采用XRD、N2吸附-脱附、NH3-TPD和吡啶吸附红外光谱(Py-IR)对3个不同硅铝摩尔比(n(SiO2)/n(Al2O3))的超细HZSM-5分子筛的结构和酸性进行表征，并在连续流动微型固定床反应器上考察它们对甲醇转化制丙烯反应(MTP)的催化性能。结果表明，随着n(SiO2)/n(Al2O3)的增加，超细HZSM-5分子筛的酸强度降低，酸量减少，MTP催化活性稳定性不断提高；丙烯和丁烯的选择性先升高后降低，而甲烷、乙烯和芳烃的选择性先降低后升高。

EFFECTS OF SILICA TO ALUMINA RATIO IN SUPERFINE HZSM-5 ZEOLITE ON THE CATALYTIC REACTION OF METHANOL TO PROPENE

The structural and acidic properties of superfine HZSM-5 zeolites with different n(SiO2)/n(Al2O3) were determined by XRD, adsorption and desorption of N2, NH3-TPD and pyridine-adsorbed infrared spectroscopy (Py-IR), and their catalytic performances for the conversion of methanol to propene(MTP) were evaluated in a fixed-bed micro-reactor under continuous flow conditions. The results showed that the intensity and amount of acidic sites in superfine HZSM-5 decreased and the catalytic stability of the superfine HZSM-5 was improved continuously with the increase of n(SiO2)/n(Al2O3). Besides, selectivity to propene and butane of MTP firstly increased, reached a maximum and then decreased, and on the contrary, selectivity to methane, ethene and aromatics firstly decreased, reached a minimum and then increased.