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用脉冲微型反应色谱研究了正己烷在不同交换度的CaNaY沸石及不同SiO_2/Al_2O_3比的HZSM-5沸石上的裂解反应及其吡啶中毒效应,测出了它们的速率常数和反应视治化能。CaNaY沸石的酸性中心数和活性部是随着 Ca~(2+)交换度的增加而增加,当Ca~(2+)交换度达60%左右时,出现一转折点,从这一点起酸性中心数们活性递增速率更快。Ca~(2+)虽然优先进入SI位,但在每个晶胞中也有两个易于被吡啶接近的酸中心。HZSM-5沸石的酸性中心数和裂解活性随着SiO_2/A_2O_3比的增加而急剧下降,直到SiO_2/Al_2O_3比到80以上时,才逐渐趋于平稳。酸性中心数和活性随硅铝比而下降的规律,正好同每个晶胞中铝原子数随硅铝比提高而下降的规律一致。
The effect of n-hexane on CaNaY zeolite with different exchange degrees and HZSM-5 zeolite with different SiO_2 / Al_2O_3 ratios and its pyridine poisoning effect was studied by pulsed microreaction chromatography. Their rate constants and reaction- . The number of acidic centers and active sites of CaNaY zeolite increase with the increase of Ca2 + exchange rate. When Ca2 + exchange rate reaches about 60%, a turning point appears. From this point, the acid sites The rate of activity is increasing at a faster rate. Although Ca ~ (2+) preferentially enters the SI site, there are also two acid sites in each unit cell that are easily accessible to pyridine. The acidic center number and the cleavage activity of HZSM-5 zeolite decreased sharply with the increase of SiO 2 / A 2 O 3 ratio, and gradually stabilized until the SiO 2 / Al 2 O 3 ratio was above 80. The decrease of acid number and activity with the ratio of Si / Al coincided with the regularity that the number of Al atoms in each unit cell decreased with the increase of Si / Al ratio.