Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan.
Angew Chem Int Ed Engl. 2018 Mar 26;57(14):3742-3746. doi: 10.1002/anie.201713308. Epub 2018 Feb 26.
The Al location in zeolites can have massive influences on the zeolite properties because it directly correlates with the cationic active sites. Herein, the synthesis of IFR zeolites with controlled Al distribution at different tetrahedral sites (T sites) is reported. The computational calculations suggest that organic structure-directing agents (OSDAs) used for zeolite synthesis can alter the energetically favorable T sites for Al. Zeolite products synthesized under identical conditions but with different OSDAs are found to have altered fractions of Al at different T sites in accordance with the energies derived from the zeolite-OSDA complexes. Our finding thus provides evidence for the ability of OSDAs to direct Al into more energetically favorable T sites, thereby offering rational synthetic guidelines for the selective placement of Al into specific crystallographic sites.
在沸石中，铝的定位对沸石的性质有重大影响，因为它与阳离子活性位直接相关。在此，报道了在不同的四面体位（T 位）具有受控铝分布的 IFR 沸石的合成。计算表明，用于沸石合成的有机结构导向剂（OSDA）可以改变对铝有利的 T 位。在相同条件下但使用不同 OSDAs 合成的沸石产物，根据沸石-OSDA 配合物衍生的能量，在不同的 T 位上具有不同比例的铝。因此，我们的发现为 OSDAs 将铝定向到更有利的 T 位的能力提供了证据，从而为选择性地将铝放置在特定的结晶位提供了合理的合成指导。
