Incorporation of Boron in Tetrahedral Sites of ZSM-5 Framework During Crystallization: A High Resolution Solid State MAS 11B-NMR Study
作者： Z. Gabelica , J.B. Nagy , G. Debras
DOI: 10.1016/S0167-2991(09)60089-6
关键词:
摘要: Aluminosilicate gels heated in Pyrex autoclaves yield crystalline ZSM-5 materials containing BO 4 units incorporated the tetrahedral sites of their framework. These groups are accurately characterized by a narrow HRMAS 11 B-NMR resonance different from one corresponding to randomly distributed precursor gel. The variation relative intensity these two lines is quantitatively related % crystallinity each intermediate phase. final may contain up 0.15 (synthesis type A) or 0.8 1.3 B) framework boron atoms per unit cell. concentration gradient within growing crystallite can be evaluated and correlated mechanism that governs nucleation growth prepared procedure.
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