Hydrogen and CO2 storage in high surface area covalent triazine–based frameworks

Abstract

Hydrogen storage and CO2 capture are of great importance for efficient fuel usage and environmentally clean methods. Here, we report a series of 7,7,8,8-tetracyanoquinodimethane-derived covalent triazine frameworks (TCNQ-CTFs) with different specific surface areas for hydrogen and CO2 storage. Such TCNQ-CTFs exhibit maximum H2 and CO2 adsorption capacities up to 2.79 wt% (77 K, 1 bar) and 5.99 mmol/g (273 K, 1 bar), respectively, which are the highest values among reported covalent triazine frameworks.Theory simulation by using the Grand Canonical Monte Carlo (GCMC) method revealed that abundant nitrogen and defects induced by annealing treatment are the reasons for the high adsorption capacity of the material. This work not only contributes a superior material for both hydrogen and CO2 storage under ambient conditions but also deepens the knowledge on its adsorption mechanism, thus guiding people to engineer more efficient storage materials.