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用(NH_4)_2TiF_6、(NH_4)_3ZrF_7和(NH_4)_3FeF_6为取代剂研究了Ti、Pe和Zr等杂原子对Y沸石的液固相类质同晶取代规律,发现Ti、Fe和Zr主要取代Y沸石中的A1,其取代程度取决于溶液中M/A1比,最高允许M/A1比与杂原子的半径和氟配合物的稳定常数有关。用XRD、IR、DTA和TPR表征了相对结晶度大于80％的杂原子Y沸石。Ti、Fe和Zr等杂原子进入Y沸石后,沸石的晶胞参数增大,热稳定性下降,红外反对称伸缩振动频率红移,且变化的程度与取代原子的半径和取代量有明显的对应关系,说明杂原子以四面体形式进入Y沸石骨架。
The substitutions of (NH 4) 2TiF 6, (NH 4) 3 ZrF 7 and (NH 4) 3 FeF 6 as substitutes for the liquid-solid isomorphous substitution of Ti, Pe and Zr heteroatoms on Y zeolites were investigated. Y zeolite A1, the degree of substitution depends on the solution M / Al ratio, the maximum allowable M / Al ratio and the radius of the heteroatom and the stability constants of fluorine complexes. Heteroatomic Y zeolites with relative crystallinity> 80% were characterized by XRD, IR, DTA and TPR. After the heteroatoms such as Ti, Fe and Zr enter Y zeolite, the unit cell parameters of zeolite increase, the thermal stability decreases, and the frequency of antisymmetric stretching and stretching is red-shifted. The degree of change and the substitution radius and substitution amount of the zeolite are obviously The correspondence indicates that the heteroatoms enter the Y zeolite framework in tetrahedral form.