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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~+)。
XRD, MASNMR, IR and NH_3-TPD techniques were used to investigate the inhibition effect of different valence metal cations into ZSM-5 zeolite cationic sites on aluminum migration under hydrothermal conditions and the change of surface acidity. Experiments show that some H ~ + in zeolite ZSM-5 is replaced by metal cation M (M = Na ~ +, Ca ~ (2+) or La ~ (3+) There is a phenomenon of migration, resulting in a decrease of total surface acid sites, of which, the decrease of strong acid sites is more consistent with that of HZSM-5 zeolites under the same hydrothermal treatment conditions. However, MZSM-5 retains more framework aluminum than HZSM- Acid center, and there is a good parallel relationship between the migration amount of aluminum and the reduction of acid center, indicating that the 1,2 or 3 valent metal cation can inhibit the aluminum migration in the ZSM-5 zeolite cation. The exchange ability of MZSM-5 zeolite to inhibit the migration of aluminum matrix was La ~ (3 +)> Ca ~ (2 +)> Na ~ + (> H ~ +).