红外光谱法研究几种类型的沸石分子筛对于2,6-二甲基呲啶的吸附特性

本文利用红外光谱法研究了几种类型的沸石分子筛对于2,6-二甲基吡啶的吸附特性。结果发现2,6-二甲基吡啶在同一种类型的沸石分子筛表面上与B酸中心、L酸中心结合的稳定性是不同的,前者比后者稳定;它在不同类型的沸石分子筛表面上与L酸中心结合的稳定性也是不相同的:对于NaHY分子筛在300-400℃,对于HM、HZSM-5、HZSM-11在150-400℃,2,6-二甲基吡啶只能选择性地被吸附在B酸中心上。在HZSM-5上进行的置换吸附实验表明,150℃在时吡啶可以定量地置换与L酸中心结合的2,6-二甲基吡啶。

Infrared Study of the Property Adsorbed 2,6-Dimethyl-Pyridine on the Several Types of Zeolite

The property adsorbed 2,6-dimcthylpyridine on the several types of zeolite has been investigated by infrared spectroscopy. The result showed that the stability of adsorption 2,6-dimethylpyridine on the Bronsted and Lewis sites of the same type of zeolite is different, the former is more stable than the latter, and that on the Lewis sites of different types of zeolite is different too, the 2,6-dimethylpyridine are adsorbed specially on the Bronsted sites in the presence of Lewis sites for NaHY at 300-400℃ and for HM, HZSM-5, HZSM-11 at 150-400℃.Competitive adsorption experiments Between pyridine and 2,6-dimethylpyridine on the HZSM-5 show that the 2,6-dimethylpyridine adsorbed on the Lewis sites can be displaced quantitatively by the pyridjne at 150℃.