| 郑步梅.碱源对低模硅比凝胶水热合成β沸石的影响[J].分子催化,2013,(5):429-438 |
| 碱源对低模硅比凝胶水热合成β沸石的影响 |
| Influence of alkali source on the hydrothermal synthesis of zeolite β with low TEAOH/SiO2 ratio |
| 投稿时间：2013-09-12 修订日期：2013-10-19 |
| DOI： |
| 中文关键词: 四乙基氢氧化铵 低模硅比 β沸石 氨水 硅铝比 |
| 英文关键词:Tetraethylammonium hydroxide Low TEAOH/SiO2 ratio Zeolite β Ammonia solution SiO2/Al2O3 ratio |
| 基金项目: |
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| 摘要点击次数: 1475 |
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| 中文摘要: |
| 本文以四乙基氢氧化铵为模板剂，研究了低模硅比条件下β沸石的合成规律。发现晶种和模板剂之间存在明显的协同导向作用。但碱源对晶种和模板剂的导向作用以及β沸石产物有明显影响。以NaOH为碱源时，晶种的作用主要是缩短晶化诱导期，而模板剂的作用主要是提高晶体生长速率。以氨水为碱源时，晶种和模板剂对缩短诱导期和提高晶体生长速率都有贡献。总的来说，以NaOH为碱源时凝胶的晶化速率较快。但是β沸石产物的硅铝比很低，且晶粒度较大，团聚体比较紧密。相比之下，以氨水为碱源有利于提高β沸石的硅铝比。同时，所合成的β沸石晶粒度小，外表面积大，团聚体中介孔较多。 |
| 英文摘要: |
| The synthesis of zeolite β in the condition of low TEAOH/SiO2 ratio was investigated. Results show that the synergistic effect existed between seed and template in terms of structure-directing synthesis. However, significant influence of alkali source on the effects of template and seed, and the property of zeolite β products was observed. When NaOH was used as alkali source, the structure-directing effect of seed was mainly reflected by shortening the induction period while that of template was mainly reflected by improving the growth rate of crystals. However, when ammonia solution was used as alkali source, seed and template were found all favoring the nucleation and crystal growth. Although NaOH-containing gel showed faster crystallization rate, it produced zeolite β with lower SiO2/Al2O3 ratio and dense aggregates which were composed of larger crystals. In contrast, the ammonia solution containing gel could produce zeolite β with much higher SiO2/Al2O3 ratio and mesopore-enriched aggregates which were composed of smaller crystals. |
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