Berzelii Centre EXSELENT on Porous Materials, and Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
Nat Chem. 2012 Jan 29;4(3):188-94. doi: 10.1038/nchem.1253.
Porous materials such as zeolites contain well-defined pores in molecular dimensions and have important industrial applications in catalysis, sorption and separation. Aluminosilicates with intersecting 10- and 12-ring channels are particularly interesting as selective catalysts. Many porous materials, especially zeolites, form only nanosized powders and some are intergrowths of different structures, making structure determination very challenging. Here, we report the atomic structures of an aluminosilicate zeolite family, ITQ-39, solved from nanocrystals only a few unit cells in size by electron crystallography. ITQ-39 is an intergrowth of three different polymorphs, built from the same layer but with different stacking sequences. ITQ-39 contains stacking faults and twinning with nano-sized domains, being the most complex zeolite ever solved. The unique structure of ITQ-39, with a three-dimensional intersecting pairwise 12-ring and 10-ring pore system, makes it a promising catalyst for converting naphtha into diesel fuel, a process of emerging interest for the petrochemical industry.
多孔材料，如沸石，具有分子尺度上明确的孔道，在催化、吸附和分离等工业领域有着重要的应用。具有十字 10-和 12-元环通道的硅铝酸盐作为选择性催化剂尤为有趣。许多多孔材料，特别是沸石，只形成纳米级的粉末，有些是不同结构的混合物，这使得结构确定变得极具挑战性。在这里，我们仅通过电子晶体学从几个单元大小的纳米晶体报告了一种沸石家族 ITQ-39 的原子结构。ITQ-39 是三种不同多晶型物的混合物，由相同的层构成，但具有不同的堆叠顺序。ITQ-39 含有堆叠缺陷和孪晶，具有纳米级的畴，是迄今为止解析出的最复杂的沸石。ITQ-39 的独特结构具有三维相交的成对 12-元和 10-元孔系统，使其成为将石脑油转化为柴油燃料的有前途的催化剂，这是石化工业新兴的关注点。
