Rational approaches toward the design and synthesis of zeolitic inorganic open-framework materials

Since the first synthesis of zeolites in 1940s, these materials and related inorganic open-framework materials with regular nanoporous space have attracted considerable interest. Zeolites are important for catalysis, adsorption, and ion-exchange, and researchers are finding new applications for these materials in optics, electronics, sensors, and medicine. In particular, the petrochemical industry is interested in the synthesis of new zeolite catalysts with high catalytic activity and selectivity. Using hydrothermal, solvothermal, and the recently-developed ionothermal methods, researchers have prepared 194 types of zeolites and thousands of zeolite-related inorganic open-framework materials. However, their syntheses are based primarily on an empirical "trial-and-error" method. The rational synthesis of zeolitic inorganic open-framework materials, while targeting novel structures and functions, remains a formidable task. The challenge in rational synthesis lies in the unknown mechanism for their formation: the relationship between the synthetic parameters and structural characteristics of the products is not clear. In an effort to overcome these challenges, our group has built up a ZEOBANK, a database of zeolite structures and a database for their synthesis. ZEOBANK allows us to use data mining to find new methods for guiding the synthesis of zeolitic materials. In this Account, we describe our efforts to rationally synthesize zeolitic inorganic open-framework materials with desired structures and present computational methods for the design of these structures. In particular, we focus on the design of zeolites with desired pore geometries through constrained assembly of atoms around the predefined channels in the unit cell. Our approaches toward rational synthesis include the use of template to direct the structure, the use of heteroatoms as a framework substituent, and the use of computational data mining. Employing these strategies, we have developed innovative methods toward the synthesis of target structures with specific channel structures, such as extra-large pores and chiral channels. We expect that further data mining will increase the synthetic control for researchers interested in designing functional zeolitic materials.