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| Initial-Gel-Composition-Dependence of Dipropylamine-Structure-Fine-Tuning Influence on the Crystallization Pathways of Aluminophosphate Molecular Sieve |
| Author Name | Affiliation | E-mail | | WANG Zi | State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China | | | YAN Wen-Fu | State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China | yanw@jlu.edu.cn | | XU Ru-Ren | State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China | |
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| Abstract: The structure-directing effect of dipropylamine isomers, i.e., di-n-propylamine (DPA) and diisopro-pylamine (D-iPA), was investigated. By heating the initial gels with certain composition at 200℃ for 24 h, highly crystalline aluminophosphate molecular sieve AlPO4-11 was obtained. The crystallization processes were investigated using X-ray diffraction, elemental analysis and pH value measurement. For the crystallization process of the initial gel with nAL2O3:nP2O5:nDPA/D-iPA:nH2O=1.0:1.0:1.2:75, no intermediate phase was formed when the DPA was used as the structure-directing agent, whereas intermediate phase of aluminophosphate molecular sieve AlPO4-5 was observed when the D-iPA was used as the structure-directing agent. For the crystallization process of the initial gel with nAL2O3:nP2O5:nDPA/D-iPA:nH2O=1.0:1.0:1.0:75, intermediate phase of aluminophosphate molecular sieve VPI-5 was formed when the DPA was used as the structure-directing agent, whereas intermediate phases of both VPI-5 and AlPO4-5 were observed when the D-iPA was used as the structure-directing agent. Theoretical calculation showed that the charge on the N of the protonated DPA was different with that on the N of the protonated D-iPA. The results indicate that the structure-directing effect of amine can be affected by the composition of the initial gel and the fine-tuning of the structure of amine can influence its structure-directing effect. However, such influence is affected by the composition of the initial gel. |
| Keywords: zeolites aluminophosphate structure-directing effect crystallization pathway intermediate phase |
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| WANG Zi,YAN Wen-Fu,XU Ru-Ren.Initial-Gel-Composition-Dependence of Dipropylamine-Structure-Fine-Tuning Influence on the Crystallization Pathways of Aluminophosphate Molecular Sieve[J].Chinese Journal of Inorganic Chemistry,2017,33(9):1595-1602. |
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