摘要
对水热处理后得到的USY沸石作进一步的酸处理以及采用改进的氟硅酸盐溶液骨架富硅工艺,分别得到了经XPS剖面分析证实为铝分布均匀的超稳Y沸石HAY-Ⅰ和HAY-Ⅱ。IR分析表明,在酸处理过程中从USY沸石中去掉的那部分非骨架铝类与3690cm^(-1)处羟基有关,仍残留在HAY-Ⅰ沸石中的那部分非骨架铝类与3670cm^(-1)和3600cm^(-1)处羟基有关。XRD和化学分析表明HAY-Ⅰ沸石仍含有约50％的非骨架铝类,而HAY-Ⅱ沸石则基本上不含非骨架铝类,HAY-Ⅱ沸石还显示更高的结晶保留度。DTA分析表明,HAY-Ⅰ和HAY-Ⅱ两种沸石的热稳定性均高于USY沸石。
HAY-Ⅰ and HAY-Ⅱ, which were two new types of ultra-stable Y zeolite with homogeneous aluminium distribution verified by XPS, were prepared by further acid leaching of zeolite USY and treatment of NH4Y zeolite by improved framework-silicon-enriched process with fluorosili-cate solution respectively. IR spoctra showed that the non-framework Al species removed from zeolite USY by acid treatment were connected with the OH group at 3690cm-1, while the remaining non-framework Al species were connected with the OH groups at 3670 cm-1 and 3600 cn-1. XRD and chemical analysis results showed that after the acid tieatment about 50% of non-framework Al still remained in HAY-Ⅰ zeolite, and there was almost no n on-framework Al species in HAY-Ⅱ, HAY-Ⅱ possessed also better crystallinity. DTA results showed that the thermal stabilities of HAY-Ⅰ and HAY-Ⅱ were all better than that of USY zeolite.
关键词
超稳Y沸石
铝分布
沸石
XPS
Ultra-stable Y zeolite ,aluminium distribution ,infrared spectroscopy,X-ray photoelectron spactroscopy
