Designed fabrication of biomimetic metal-organic frameworks for catalytic applications

Enzymes are among the most sophisticated catalysts with unique features of high substrate affinity, unmatched catalytic efficiency and specificity. However, their practical applications are hindered by their high cost, the highly restricted catalytic conditions and their fragile nature. To solve these problems of enzymes for practical applications, biomimicry has therefore emerged as an effective approach to synthesize highly efficient biomimetic catalysts by imitating certain key features of enzymes. To tune the pore structures and modify the functional groups of metal organic frameworks (MOFs), the porosity, functionality and hydrophobic/hydrophilic pore nature of the emerging porous materials are systematically tunable, which endow them to match certain enzymatic features, including structural features, active sites, microenvironments, assistant sites and/or catalytic properties of enzymes. Compared with their enzyme counterparts, biomimetic MOF catalysts present the advantages of broadened applicable conditions and enhanced stability, and sometimes they exhibit catalytic properties that are not possessed by the native enzymes. This review will selectively illustrate biomimetic MOF catalysts, consisting of immobilized biomimetic active sites on the pore surfaces or inside the pore space of porous MOFs. We will discuss the design principles and synthetic strategies for biomimetic MOF catalysts, and the relationships between their catalytic properties and structures. The key roles of active sites, microenvironment, transmission channels and co-catalytic sites, associated with the synergistic catalysis of biomimetic MOFs, will be addressed. (C) 2018 Elsevier B.V. All rights reserved.