A Stable Extra-Large Pore and High-Silica Zeolite Derived from Ge-Rich Precursor

A multidimensional extra-large pore zeolite with highly hydrothermal stability, denoted as −IRT−HS, has been developed successfully, starting from Ge-rich germanosilicate precursor hydrothermally directed by a small and commercially available piperidinium-type organic structure-directing agent (OSDA). −IRT−HS, with the supermicropores, is structurally analogues to 28-membered ring −IRT topology as confirmed by various spectroscopic techniques. And it is the high-silica (Si/Ge=58) zeolite with the largest pore size as well. Notably, using acid-washed as-made Ge-rich −IRT precursor as the silicon source is crucial to restore partially collapsed structure into a stable framework by OSDA-assisted recrystallization. The calcined −IRT−HS maintains a high crystallinity, even when stored in a humid environment for extended periods or directly exposed to water. Additionally, high silica Al-containing analogue is also readily synthesized, serving as an active solid-acid catalyst in 1,3,5-triisopropylbenzene cracking reaction, yielding an impressive initial conversion up to 76.1 % much higher than conventional large-pore Beta zeolite (30.4 %). This work will pave the way for the designed synthesis of targeted high-silica zeolites with stable and extra-large pore frameworks, mimicking the structures of existing Ge-rich counterparts.