Facile synthesis of microporous carbon xerogels for highly selective CO2 adsorption

Microporous carbon xerogels (CXs) were successfully fabricated via a facile one-pot strategy using eutectic salt mixture (KCl and ZnCl2) as dual activator and catalyst. Their pore structures, morphology, and selective CO2 adsorption behaviors were thoroughly studied by varying the contents of eutectic salt mixture. The presented CXs herein showed excellent CO2 adsorption selectivities, and the CX-4 with optimum salt concentration (12.9%) exhibited the highest CO2 adsorption capacity of 4.39 mmol g−1 at 273 K, which was ascribed to their special microscopic pore structure. Compared with the reported carbon materials, the optimum CX-4 exhibits a comparable or superior CO2 adsorption performance under similar conditions, showing great potential for efficient CO2 capture and separation from flue gas and natural gas.