Lower Activation Energy for Catalytic Reactions through Host-Guest Cooperation within Metal-Organic Frameworks

Angew Chem Int Ed Engl. 2018 Aug 6;57(32):10107-10111. doi: 10.1002/anie.201803081. Epub 2018 Jun 1.

Abstract

Industrial synthesis is driven by a delicate balance of the value of the product against the cost of production. Catalysts are often employed to ensure product turnover is economically favorable by ensuring energy use is minimized. One method, which is gaining attention, involves cooperative catalytic systems. By inserting a flexible polymer into a metal-organic framework (MOF) host, the advantages of both components work synergistically to create a composite that efficiently fixes carbon dioxide to transform various epoxides into cyclic carbonates. The resulting material retains high yields under mild conditions with full reusability. By quantitatively studying the kinetic rates, the activation energy was calculated, for a physical mixture of the catalyst components to be about 50 % higher than that of the composite. Through the unification of two catalytically active components, a new opportunity opens up for the development of synergistic systems in multiple applications.

Keywords: carbon dioxide fixation; cooperative catalysis; host-guest cooperation; ionic polymers; metal-organic frameworks (MOFs).