Size-Controlled Synthesis of Nano-Zeolites and Their Application to Light Olefin Synthesis
Size-Controlled Synthesis of Nano-Zeolites and Their Application to Light Olefin Synthesis
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DOI：
10.1007/s10563-012-9141-4
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发表时间：
2012-07
影响因子：
3
通讯作者：
T. Tago;Hiroki Konno;Y. Nakasaka;T. Masuda
中科院分区：
文献类型：
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作者：
T. Tago;Hiroki Konno;Y. Nakasaka;T. Masuda
对于沸石作为非均相催化剂的应用，降低烃类在微孔内的扩散阻力是提高产物选择性和催化剂寿命的必要条件。这个问题已经通过减小晶体尺寸得到了解决。介绍了水/表面活性剂/有机溶剂水热合成纳米沸石（乳液法）的粒径控制方法及其在非均相催化剂上的应用。表面活性剂分子中亲水性基团的离子性和Si源的浓度影响了乳液法制备的沸石的结晶度和形貌。当使用非离子表面活性剂时，成功地制备了直径约60 nm的单分散硅-1纳米晶体。制备了晶粒尺寸为~150 ~ 200 nm和1.5 μm的纳米和宏观zsm -5分子筛，并进行了吨己烷裂化反应和丙酮-烯烃反应，考察了分子筛晶粒尺寸对催化稳定性和轻烯烃收率的影响。将纳米沸石应用于轻质烯烃生产中，可以有效地实现微孔内烃类分子更快的传质，从而提高烯烃收率和催化剂寿命。
For the application of zeolites as heterogeneous catalysts, low diffusion resistance for hydrocarbons within the micropore is essential for improving product selectivity and catalyst lifetime. This problem has been overcome by reducing the crystal size. This review introduces size-controlled preparation of nano-sized zeolites via hydrothermal synthesis in water/surfactant/organic solvent (emulsion method) and their application to heterogeneous catalysts. The ionicity of the hydrophilic group in surfactant molecules and the concentration of the Si source affected the crystallinity and morphology of zeolites prepared using the emulsion method. When using a non-ionic surfactant, mono-dispersed silicalite-1 nanocrystals ~60 nm in diameter were successfully prepared. Nano- and macro-ZSM-5 zeolites with crystal sizes of ~150–200 nm and 1.5 μm, respectively, were prepared and applied ton-hexane cracking and acetone-to-olefin reactions to investigate the effect of zeolite crystal size on catalytic stability and light olefin yield. Application of nano-zeolite to light olefin production was effective in achieving faster mass transfer of hydrocarbon molecules within the micropore, which led to improvements in olefin yields and catalyst lifetime.