N-Containing Carbons Derived from Microporous Coordination Polymers for Use in Post-Combustion Flue Gas Capture

Herein, novel carbons that, owing to a high density of micropores (up to 79%) and N-content (up to 14.9%), offering exciting potential for post-combustion CO2 capture are reported. Given that little is known about how starting materials impact the structure and performance of carbons, three different microporous materials are pyrolyzed. These include a Co-(metal-organic framework) (MOF), a Co-MOF-polymer composite, and a coordination polymer derived from the same monomer and cobalt ions. Notably, the cobalt, which is required to drive the polymerization, is subsequently leached from the carbons via acid for its reuse in MOF synthesis. Next, various metrics including CO2 capacity, selectivity, isosteric heat of adsorption, breakthrough time and cyclability are assessed. The acid treated carbons adsorb 0.21, 0.99, and 1.11 mmol CO2 g(-1), respectively, (313 K, 0.15 bar) with CO2/N-2 selectivity ranging from 37 to 52. Due to superior capacity, the polymer-derived carbons also reveal impressive breakthrough times in simulated flue gas mixtures (15% CO2/85% N-2, 80% RH, 313 K) ranging from 33 to 40 min g(-1). Similar performance is also observed under dry conditions and after pre-saturation with water for 1.5 h. Remarkably, no loss in working capacity is observed after 100 CO2 TSA cycles (313 K/393 K).