ADOR zeolite with 12 × 8 × 8-ring pores derived from IWR germanosilicate†

Abstract

Zeolites have been well known for decades as catalytic materials and adsorbents and are traditionally prepared using the bottom-up synthesis method. Although it was productive for more than 250 zeolite frameworks, the conventional solvothermal synthesis approach provided limited control over the structural characteristics of the formed materials. In turn, the discovery and development of the Assembly-Disassembly-Organization-Reassembly (ADOR) strategy for the regioselective manipulation of germanosilicates enabled the synthesis of previously unattainable zeolites with predefined structures. To date, the family tree of ADOR materials has included the topological branches of UTL, UOV, IWW, *CTH, and IWV zeolites. Herein, we report on the expansion of ADOR zeolites with a new branch related to the IWR topology, which is yet unattainable experimentally but theoretically predicted as highly promising adsorbents for CO ₂ separation applications. The optimization of not only the chemical composition but also the dimensions of the crystalline domain in the parent IWR zeolite in the Assembly step was found to be the key to the success of its ADOR transformation into previously unknown IPC-17 zeolite with an intersecting 12 × 8 × 8-ring pore system. The structure of the as-prepared IPC-17 zeolite was verified by a combination of microscopic and diffraction techniques, while the results on the epichlorohydrin ring-opening with alcohols of variable sizes proved the molecular sieving ability of IPC-17 with potential application in heterogeneous catalysis. The proposed synthesis strategy may facilitate the discovery of zeolite materials that are difficult or yet impossible to achieve using a traditional bottom-up synthesis approach.

Abstract

Addressing the synthesis–property relations in the Assembly step of ADOR enabled to design previously unknown IPC-17 zeolite by optimization of the chemical composition and crystallite dimensions in the parent IWR germanosilicate.