氟元素对HY型分子筛性能的影响

EFFECT OF INTRODUCING FLUORINE INTO HY ZEOLITE

使用氟化铵对HY型分子筛进行改性引入氟原子,获得含氟分子筛。通过DTA、BET、吡啶-TPD、XRD方法表征含氟分子筛的热稳定性、比表面积、孔体积、酸性和晶体结构,用邻二甲苯为模型化合物表征分子筛的催化性能。结果表明,HY型分子筛载氟量适当可以显著提高其酸性,改善其热稳定性、孔结构和晶体结构,提高其在邻二甲苯催化转化中的催化活性。

The thermal stability, surface area, pore volume, acidity and crystal structure of HY zeolite modified by NH4F were characterized with DTA, BET, Pyridine-TPD and XRD, and its catalytic performance was tested by using o-xylene as model compound. The results showed that the fluo-rine with proper amount for HY zeolite modification could increase its acidity and thermal stability, as well as improve the pore structure and crystal structure. The modified HY zeolite also presented higher catalytic activity for o-xylene conversion.