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

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. Nitrogen doped carbon derived from 7,7,8,8-tetracyanoquinodimethane covalent triazine frameworks exhibits ultra-high H2 and CO2 adsorption capacities under ambient pressure, which are among the highest level of reported CTF to our knowledge. [Display omitted] •The CNQ-CTF-900shows ultra high specific surface area (4000 m2/g).•The TCNQ-CTF-900 shows a very high carbon dioxide uptake of 5.99 mmol/g (273 K, 1 bar).•TCNQ-CTF-900 exhibits the highest H2 adsorption capacities among all of the reported covalent triazine frameworks thus far.•The high adsorption of the material was also investigated through theoretical calculation.