Synthesis and Characterization of Covalent Triazine Frameworks Based on 4,4'-(Phenazine-5,10-diyl)dibenzonitrile and Its Application in CO/CH Separation.

Covalent triazine frameworks (CTFs) have gained recognition as stable porous organic polymers, for example, for CO separation. From the monomer 4,4'-(phenazine-5,10-diyl)dibenzonitrile (pBN), new pBN-CTFs were synthesized using the ionothermal method with a variation in temperature (400 and 550 °C) and the ZnCl-to-monomer ratio (10 and 20). N adsorption yielded BET surface areas up to 1460 mg . The pBN-CTFs are promising CO adsorbents and are comparable to other benchmark CTFs such as CTF-1 with a CO uptake of pBN-CTF-10-550 at 293 K of up to 54 cm g or 96 mg g, with a CO/CH IAST selectivity of 22 for a 50% mixture of CO/CH. pBN-CTF-10-400 has a very high heat of adsorption of 79 kJ mol for CO near zero coverage in comparison to other CTFs, and it also stays well above the liquefaction heat of CO due to its high microporosity of 50% of the total pore volume.