Rational design of Cu(I)-anchored porous covalent triazine framework (CTF) for simultaneous capture and conversion of CO2 at ambient conditions

Abstract

The selective carbon capture and utilization (CCU) as a C1 source is sought to be an important step towards environmental remediation and sustainable production of useful chemicals. In this context, herein, we report the strategic integration of noble metal-free Cu(I) catalytic sites with a nitrogen-rich, CO2-philic, bipyridine functionalized covalent triazine framework (bipy-CTF) by a post-synthetic approach. The Cu(I)@bipy-CTF showed very good performance for simultaneous capture and fixation of CO2 into α-alkylidene cyclic carbonates (α-aCCs), high-value commodity chemicals at ambient conditions. Further, the Cu(I) anchored bipy-CTF showed high CO2 affinity with the interaction energy of 44.09 kJ/mol attributed to the presence of CO2-philic, basic nitrogen sites. The presence of both CO2-philic nitrogen and alkynophilic Cu(I) sites decorated in the 1D channels of bipy-CTF provided a good catalytic activity for the chemical fixation of carbon dioxide from dilute gas (13 % CO2) to yield α-aCCs at atmospheric pressure (balloon) of CO2. Notably, Cu(I)@bipy-CTF showed high recyclability and chemical stability for multiple catalytic cycles. Overall, the present work represents a rare example of a COF-based recyclable catalyst for CO2 fixation from dilute gas into valuable chemicals under mild conditions.