Computer-aided design of composite metal-organic frameworks

Abstract

Metal-organic frameworks (MOFs) which consist of metal complex and organic ligand with coordination bonding are crystalline nanoporous materials and more than 80,000 MOFs have been synthesized with diverse components. MOFs can be applied to adsorbent, catalyst, sensor, gas storage and separation by virtue of high surface area and high tunability. Composite metal-organic frameworks which consist of MOF and other materials and complement each other have been actively studied for the last 10 years to apply MOFs to realistic applications. However, the number of MOF-MOF composite materials was limited despite the conceivable combinations of MOF-MOF were enormously large. Therefore, it is important to investigate the unexplored material space of MOF-MOF composite, design and synthesize the new composite MOF-MOF. For efficient discovery of new composite materials, a joint computational/experimental approach where computational screening is conducted to find more possible candidiates before experimentalists try to synthesize new materials is necessary. In this thesis, computational design of (1) hetero-interpenetrated MOFs and (2) MOF@MOF or Core-Shell MOF composite were conducted using large MOF database and algorithm to analyze the structural information and identify whether MOF composite can be formed using two different MOF structures. Furthermore, for the real synthesis of polymorphic MOFs which have good properties but are difficult to be directly synthesized, MOF assembly algorithm using top-down approach and algorithm for MOF@MOF screening were combined to obtain the pairs of polymorphic MOF and the seed MOF which can be used to synthesize the polymorphic MOF. As a results, the new types of composite MOFs were computationally designed and the predicted core shell MOFs were successfully synthesized in experiments. The results demonstrate that computational method can be useful tool to accelerate the development of new composite MOF.