ZSM-5沸石骨架铝迁移规律的研究 Ⅱ.不同价态金属阳离子对ZSM-5沸石骨架铝迁移的影响  

STUDIES ON THE MIGRATION OF FRAMEWORK ALUMINIUM OF ZSM-5 ZEOLITE Ⅱ. EFFECT OF METAL CATIONS ON THE MIGRATION OF FRAMEWORK ALUMINIUM OF ZSM-5 ZEOLITE

作　　者：汪树军[1] 梁娟[1] 郭文珪 赵素琴[1] 李宏愿[1] 

机构地区：[1]中国科学院大连化学物理研究所,大连116023

出　　处：《Chinese Journal of Catalysis》1992年第4期279-284,共6页催化学报（英文）

基　　金：国家自然科学基金;波谱与原子分子物理实验室资助项目

摘　　要：用XRD,MASNMR,IR及NH_3-TPD等技术考察了不同价态金属阳离子引入ZSM-5沸石阳离子位对水热条件下骨架铝迁移的阻抑作用以及表面酸性的变化。实验证明,ZSM-5沸石中部分H^+被金属阳离子M(M=Na^+,Ca^(2+)或La^(3+)取代后,在≥400℃水热条件下骨架铝仍有迁脱现象,致使表面总酸中心减少,其中强酸中心减少较多,和相同水热处理条件下HZSM-5沸石的变化规律一致,但MZSM-5较HZSM-5保留有较多的骨架铝及酸中心,且骨架铝的迁脱量和酸中心的减少有很好的平行关系,说明1、2或3价金属阳离子进入ZSM-5沸石阳离子位都具有阻抑骨架铝迁移的作用。等当量交换的MZSM-5沸石阻抑骨架铝迁移的能力为La^(3+)>Ca^(2+)>Na^+(>H^+)。The migration of framework Al of ZSM-5 zeolite containing various cations M (M = Na+, Ca2+, La3+) and its surface acidity after hydrother-mal treatment were studied by using XRD, MASNMR, IR and NH3-TPD techniques. The results showed that when protons in the channel were partially replaced by M ions, more framework Al and at the same time a greater surface acidity were reserved for the MZSM-5 after steaming in comparison with the HZSM-5. With either HZSM-5 or MZSM-5, parallel relation was obtained between the loss of framework Al and the loss of surface acidity, which is consistent with that for ZSM-5 zeolite the acidity is related to the Al content. It was found that the ability of M ions to retard the migration of framework Al at a comparable exchange degree of proton was in the order of La3 + >Ca2 + >Na+>(H+). This order is explained on the basis of structural factors of ZSM-5 and the nature and valency of the cations.

关 键 词：ZSM-5沸石 骨架铝迁移 

分 类 号：TQ426.7[化学工程]