Construction of a highly heteroatom-functionalized covalent organic framework and its CO2 capture capacity and CO2/N2 selectivity

Abstract

In this study, the triazine-based covalent organic framework (TMFPT-COF) with a 2D structure was successfully constructed by the condensation reaction of 2,4,6-tris-(3-methoxy-4-formylphenyl)- 1,3,5-triazine (TMFPT) and hydrazine hydrate as building units under solvothermal conditions. The TMFPT-COF possessed high crystallinity, and superior chemical and thermal stabilities. The Braunauer-Emmett-Teller (BET) specific surface area up to 1407 m2 g−1 was obtained for the framework material with a pore volume of 0.97 cm3 g−1. With abundant microporous structure and large specific surface area together with heteroatom-rich environment, the obtained framework showed a strong affinity for CO2 with considerably high enthalpy (34.1 kJ/mol). The resulting COF also exhibited moderate selective CO2/N2 adsorption with selectivity factor of 19 (Henry) and 17 (IAST) (1 bar, 273 K). Remarkably, TMFPT-COF was proposed to serve as a candidate with the potential in the practical application for selective CO2 adsorption.