摘要
应用红外光谱研究了异己烷、正己烷、己烯-1、环己烯、苯等碳六烃在Y沸石表面的吸附过程。发现烃吸附后,超笼羟基消失;不饱和烃吸附后,同时还在3400—3000cm^(-1)区出现一个峰巅频率不同的大峰包,系烃类的离域π电子与表面羟基作用形成氢键的结果。小笼羟基程度不等地向低频位移,这些作用随不饱和烃π键增强而加剧。小笼羟基强度有增强的现象,这可能是由于吸附的烃类使超笼羟基指向小笼或质子迁移所引起。小笼羟基增强程度与烃的H/C比、烃吸附量及烃结构有明显的依赖关系。
The adsorption of iso-hexane , n-hexane, 1-hexene, benzene and cyclohexene on HY zeolite has been studied by IR spectroscopic technique. After hydrocarbon adsorbed on HY, the stretching band of OH in supercages reduces greatly; if the hydrocarbon adsorbed is unsaturated, a broad band in the region of 3400-3000cm-1 appears, this phenomenon is perhaps due to the H-bond formation by the interaction of π system of unsaturated hydrocarbon with acidic OH groups in supercages. The stretching band of OH in cubooctahedra shifts more or less to lower wave-number, the higher the density of π electron cloud of the adsorbate ,the more remarkable the phenomenon is. The stretching band of OH in cubooctahedra is strengthened, the reason for this is that the vibrational direction of partial OH in supercages is changed toward cubooctahedra by the adsorption of saturated hydrocarbon. This phenomenon is related to the structure of the adsorbate and the H/C ratio.
基金
国家自然科学基金