Seed-assisted, template-free synthesis of ZSM-5 zeolite from natural aluminosilicate minerals
Seed-assisted, template-free synthesis of ZSM-5 zeolite from natural aluminosilicate minerals
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DOI：
10.1016/j.clay.2018.03.025
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发表时间：
2018-06
影响因子：
5.6
通讯作者：
Yuanyuan Yue;Kang Ying;B. Yu;L. Gu;Haiyan Liu;Jie Bao;Tinghai Wang;Pei Yuan;Haibo Zhu
中科院分区：
文献类型：
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作者：
Yuanyuan Yue;Kang Ying;B. Yu;L. Gu;Haiyan Liu;Jie Bao;Tinghai Wang;Pei Yuan;Haibo Zhu
在结构导向剂存在下，以化学Al/Si源水热合成沸石被认为是一种资源消耗、能源消耗和环境不友好的方法。在此，我们报告了一种新的，成本有效的，和生态友好的合成ZSM-5沸石的制备从富硅沸石和富铝累托石矿物在没有有机结构导向剂和化学Al/Si源。系统研究了合成因素（SiO2/Al 2 O3、Na 2 O/SiO2、H2O/SiO2摩尔比沿着晶种含量的变化）和晶化行为，为天然矿物合成ZSM-5沸石提供了基础知识。在优化的合成条件下（SiO2/Al 2 O3 = 38左右，Na 2 O/SiO2 = 0.12-0.15，H2O/SiO2 = 15-25，晶种含量大于0.5%），合成的ZSM-5分子筛具有六棱柱形貌和大比表面积。不同晶化时间的产物表征技术表明，该晶化过程分为3个阶段：短诱导期（0-6 h）、快速生长期（6-18 h）和稳定生长期（18-36 h）。此外，合成的ZSM-5晶体可用作制备下一代ZSM-5沸石的有效晶种。
The hydrothermal synthesis of zeolite from chemical Al/Si source in the presence of structure directing agent is considered to be a resource extensive, energy consuming, and environmental unfriendly process. Herein, we report a novel, cost-effective, and eco-friendly synthesis for the preparation of ZSM-5 zeolite from silicon-rich diatomite and aluminum-rich rectorite minerals in the absence of organic structure-directing agent and chemical Al/Si source. Synthesis factors (SiO2/Al2O3, Na2O/SiO2, and H2O/SiO2molar ratios along with seed content) and crystallization behavior were systematically investigated, providing fundamental knowledges on the formation of ZSM-5 from natural minerals. Synthesis under the optimized conditions (SiO2/Al2O3ratio of around 38, Na2O/SiO2ratios of 0.12–0.15, H2O/SiO2ratios of 15–25, and seed content above 0.5%) led to production of highly crystalline ZSM-5 zeolite with hexagonal prism morphology and large surface area. Various characterization techniques tracking the products at different crystallization times revealed that the crystallization process consisted of three stages: short induction stage (0–6 h), rapid growth stage (6–18 h), and stable growth stage (18–36 h). Moreover, the synthesized ZSM-5 crystals can be used as effective seed for producing the next generation of ZSM-5 zeolite.