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采用SiCl_4同晶取代NaY沸石,制备了硅铝比变化较宽且结晶度完好的八面沸石,进一步将样品交换为铵型,还制备了铝交换型八面沸石及越稳Y样品。红外研究发现,随硅铝比增加,八面沸石样品的两种典型羟基谱带频率发生规律性变化,且于3600及3666cm~(-1)附近相继出现新的羟基吸收谱带,其小笼羟基质子酸性逐渐增加,沸石体系B酸总量逐渐降低,而强B酸量则呈山峰形变化,骨架外铝对硅铝比较低的样品的酸性影响较大,在骨架硅铝比相近情况下,高温水热法脱铝样品(USY)较SiCl_4脱铝样品(DNH_4Y)的羟基谱带和酸性具有明显的差异。
SiCl 4 was used to replace NaY zeolite to prepare a faujasite zeolite with wide change of Si / Al ratio and good crystallinity. The samples were further exchanged for ammonium and aluminum exchange faujasite and more stable Y samples were also prepared. Infrared studies found that with the increase of silica to alumina ratio, the frequency of two typical hydroxyl bands of faujasite zeolites changed regularly, and new hydroxyl absorption bands appeared around 3600 and 3666 cm -1, The acidity of hydroxyl protons increases gradually, the total amount of B acid in zeolite system gradually decreases, while the amount of strong B acid changes in mountain shape. The extra-framework aluminum has a greater influence on the acidity of samples with lower silicon-aluminum ratio. , The hydroxyl bands and acidity of high temperature hydrothermally dealuminated samples (USY) were significantly different from those of SiCl_4 dehalogenated samples (DNH_4Y).