내장형 망상 위상 구조를 갖는 제올라이트의 합성과 특성분석 및 이산화탄소 흡착 특성 연구

Abstract

The targeted preparation of novel zeolite structures with desired physicochemical properties for a specific application is one of the most challenging issue in the field of zeolite synthesis. Although millions of hypothetical zeolite structures have been already predicted, their synthesis mechanism is not known enough to allow any given structure to be prepared. Our recent studies have provided a new principle of structure expansion denoted ‘embedded isoreticular’ in RHO-family zeolites. We could then predict the other members of a family of increasingly complex but structurally-related zeolites and this inspired synthesis of a more complex zeolite PST-20. Here we report that three members of the next, even more super complex zeolites denoted PST-25, PST-26, and PST-28 can be prepared by modification of PST-20 synthesis condition such as the type of alkaline-earth cations, SiO2/Al2O3 ratios, and H2O contents, although they are obtained as a mixture. The successful syntheses of these materials were identified by using a combination of rotation electron diffraction and Lebail refinement. We also report that these materials show selective adsorption for CO2, fast kinetics and long-term stability comparable to that observed for to the lower members of the RHO-family, such as ZSM-25 and PST-20.