摘要
以XRD和IR方法测定了一系列盐酸水热处理方法所制得的脱铝丝光沸石样品的晶体结构参数和骨架组成。证实丝光沸石在94～96℃下经盐酸溶液(1mol/L)处理并经高温(550℃)灼烧后,骨架中部分铝被脱除导致晶格b轴方向显著收缩;丝光沸石单胞铝原子数与晶胞参数非线性相关;脱铝程度较高的样品其骨架振动IR谱可明显地观察到新Si-O键的形成,晶胞中处在不同位置上的骨架Al其脱除顺序与脱除量不同。脱铝丝光沸石样品对α-蒎烯乙氧基化反应的催化活性、选择性随骨架SiO_2/Al_2O_3比的增大而提高,骨架SiO_2/Al_2O_3比[(SiO_2/Al_2O_3)_(?)]大于38时,选择性有所下降。
Structural parameters have been determinated with XRD for dealuminized mordenites (preparated from Na-mordenite treated with 1mol/L hydrochloric acid and calcined at 550℃ in air). Changes in framework composition of DHM have been investigated with 1R spectroscopic method. It has been con- firmed that part of aluminum is removed and the lattice significantly constracts in b-axis, as mordenite is treated in 1mol/L hydrochloric acid at 94～96 C following by calcination. But plots a, b or c di- mensions vs Al/u. c. are nonlinear. When the aluminum content has been decreased to a certain level during dealuminization treatment, further dealuminization treatments induce remarkable increasing in crystallinity of DHM and a new band at 820cm^(-1) on framework vibration IR spectroscopy. This new band is due to the symmetrical streching vibration of new Si-O bonds. The catalytic behaviours of DHM to the reaction of α-pinene with EtOH have been explored tentatively. The experimental results indecate that the catalytic activity and selectivity raises with the (SiO_2/Al_2O_3)_(fr) increasing when (SiO_2/Al_2O_3)_(fr) value is lower than 38. It is notable that the selectivity decreases when the (SiO_2/ Al_2O_3)_(fr) of DHM is higher than 38.
出处
《石油炼制》
CSCD
1992年第10期28-32,共5页
基金
国家自然科学基金
