Y型沸石分子筛羟基谱带的红外光谱研究

本文制备了一系列不同硅铝比的Y型沸石样品,以红外光谱法系统地研究了样品的羟基谱带及其变化情况。结果表明,Y型沸石羟基谱带随沸石体系组成的变化及晶格空位和骨架外铝的出现而发生一系列的变化,样品表面羟基振动频率受骨架内电负性和骨架外电荷变化的影响会产生规律性的位移,进一步还讨论了其作用的机理,另外讨论和归属了Y型沸石常出现的几种羟基红外吸收谱带。

Ir Stuby on Hydroxyl Bands of Y Type Zeolites

In the paper the preparatioa of dealuminated Y type zeolites by SiC14 vaporsubstitution method and the studies on hydroxyl bands by infrared spectoscopyare reported. It is found that, as the composition of Y type zeoliteschanged as well as the framework vacancies and extraframework aluminaappeared, the new hydroxyl bands at 3666 and 3600 cm~(-1) developed, whichhave been attributed to the hydroxyl attached to the framework vacancies andextraframework alumina respectively. As the samples adsorbed pyridine, thefrequency of hydroxyl bands will be shifted to the high position but onlyhydroxyl bands in small cavity shifted to the low figure. A convincing interp-retation and discussion on the above results has been mads with the aid of theresults that the framework electronagetivity and the extraframework chargechanged before and after the samples adsorbing pyridine. The IR results indi-cate that. when the samples adsorbed pyridine, the band 1490cm~(-1) may berepresent another type acid site or another state of pyridine adsorbtion whichdiffered from the acid site or the pyridine adsorbed state represented by 1540and 1450cm~(-1).