Chapter 6. Rational Design of Covalent Organic Frameworks for High Performance Gas Storage

Abstract

Covalent organic frameworks (COFs) are periodic porous polymers with relatively high crystallinity, which have become a newly emerging family of materials. The COF materials are constructed by covalent bonds (B–O, C–C, C–N etc.) of light elements, and by using various organic building blocks we can create versatile COFs with diverse topology and functionalities. The COFs often possess the characteristics of low density, high porosity and large specific surface area, and have therefore been widely applied in gas adsorption and separation, energy chemistry and the environmental fields. To develop COF materials with appreciable functionalities, extensive experimental and theoretical techniques are being employed. In particular, multiscale simulation methods have been proven to be an efficient tool to design and investigate the properties of new COFs. This article mainly introduces two rational strategies to design new COF materials. One is linker replacement or the node replacement strategy to achieve high performance gas storage COF materials with large surface areas and pore volumes. The other is functional group modification or the metal doping strategy to design functionalized COFs with strong affinity towards gases. For the two design strategies, we also give a corresponding example for further analysis. Finally, we summarize the applications of COFs in hydrogen and methane storage, as well as CO2 capture.