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

Abstract

AbstractA 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.