Repurposing Templates for Zeolite Synthesis from Simulations and Data Mining

Abstract

[EN] Zeolites span a large variety of microporous crystal structures, making them useful materials for catalysis and separations. However, controlling phase competition in their synthesis often requires organic structure-directing agents (OSDAs) to selectively crystallize the desired topologies. Whereas computational design of OSDAs can help in selecting adequate candidates for zeolite synthesis, machine-generated templates are often complex or expensive. In this work, we use shape and binding metrics to propose templates for over 100 zeolites and to rationalize dual-OSDA approaches. Starting from OSDAs from the literature, promising templates were selected for zeolites ranging from clathrasil frameworks to extra large-pore structures. Selectivity maps derived from phase competition metrics show that small- and medium-pore zeolites tend to be more shape-selective toward their templates than their large-pore counterparts. Finally, shape and volume descriptors allow identification of OSDAs that may act as synergistic pore-fillers for different cavities of zeolites. The application of this theory is demonstrated for the case of the KFI zeolite, which may be synthesized using tetraethylammonium and OSDAs repurposed from high-silica LTA synthesis as dual OSDAs. This work may help in the discovery of new synthesis routes for known zeolites using shape descriptors and repurposed OSDAs.