Enhancing low pressure CO2 adsorption of solvent-free derived mesoporous carbon by highly dispersed potassium species

Abstract

Highly dispersed potassium species were introduced on a mesoporous carbon surface following an oxidation and subsequent ion exchange protocol. The samples were characterized and their CO₂ adsorption performance was systematically evaluated by both static and dynamic adsorption tests. It was found that the generated surface functionality can be tuned by controlling the reaction temperature and/or using different oxidant(s), and thus potassium species can be introduced in an adjustable way without significant alteration on the textural properties of the samples. Although adsorption at atmospheric pressure was not influenced, low pressure CO₂ uptake and adsorption selectivity were considerably enhanced by potassium introduction owing to the highly dispersed potassium species. A high CO₂ adsorption capacity of 5.9 wt% was achieved at 25 °C and 0.15 bar with excellent cyclic stability, and the adsorbents can be readily regenerated at 115 °C under N₂ purging.