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Combined Alkali-Organoammonium Structure Direction of High-Charge-Density Heteroatom-Containing Aluminophosphate
Seungwan Seo1, Nak Ho Ahn1, Jeong Hwan Lee1
1Center for Ordered Nanoporous Materials Synthesis, Division of Environmental Science and Engineering, POSTECH, Pohang, 37673, Korea.
Abstract:
The charge density mismatch concept was applied to the synthesis of high-charge-density silicoaluminophosphate SAPO-69 (OFF) and SAPO-79 (ERI) and zincoaluminophosphate PST-16 (CGS), PST-17 (BPH), PST-19 (SBS), and ZnAPO-88 (MER) molecular sieves. Combined alkali-organoammonium structure direction in these systems is thus enabled. Structure direction is treated from the perspective of stabilizing an ionic framework, the relationships between reaction charge density (OH- /H3 PO4 ), alkali and organoammonium content, and ionicity of tetrahedral framework atoms in successful structure direction are presented.
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