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用红外光谱法考察了HY,CaHY,LaHY及相应的经超稳化处理的USY,CaUSY,LaUSY分子筛。也对比了HY,USY及其进一步用NH_4~+交换的USYH分子筛。USY的3700cm~(-1)特征谱带强度不仅与Na~+含量有关,也与其它阳离子如Ca~(2+),La~(3+)的含量有关。从OH基伸缩振动区的谱带看到,La有稳定结构羟基和抑制脱铝的作用。观察了各超稳化分子筛的各个OH基谱带及它们在不同吡啶脱附温度下的变化。HY,USY刚USYH的酸量及其强度有很大差别,它们的B酸强度不同,USYH的L酸强度出乎预料地高。正癸烷裂化活性与B酸有较好对应关系。讨论了超稳化处理、阳离子性质、后NH_4~+交换等因素对分子筛的酸性、稳定性和酸中心可接近性的影响。
The HY, CaHY, LaHY and the corresponding USY, CaUSY and LaUSY zeolites were investigated by IR spectroscopy. We also compare HY, USY and their USYH molecular sieves further exchanged with NH 4 +. The intensity of the 3700cm -1 characteristic band of USY is not only related to Na ~ + content but also related to other cations such as Ca ~ (2 +) and La ~ (3+). It can be seen from the band of OH stretching vibration region that La has a stable structure of hydroxyl group and inhibits dealumination. The OH bands of each ultrastable molecular sieve were observed and their changes at different pyridine desorption temperatures were observed. HY, USY Just USYH acid strength and its strength are very different, their B acid strength is different, USYH L acid strength unexpectedly high. N-decane cracking activity and B acid have a good correspondence. The effects of ultrastabilization treatment, cationic properties and post NH 4 + exchange on the acidity and stability of zeolites and accessibility of acid sites were discussed.