Nitrogen-Doped Coal Tar Pitch Based Microporous Carbons with Superior CO2 Capture Performance

Abstract

Coal tar pitch based nitrogen-doped porous carbons were developed by FeCl3 activation for enhanced CO2 capture. The carbon materials, synthesized with different FeCl3/carbon precursor mass ratios and activation temperatures, exhibit high porosity, especially microporosity, and nitrogen species contents, leading to superior CO2 adsorption capacities in the range of 3.71–4.58 mmol g–1 and 5.68–7.18 mmol g–1 at 25 and 0 °C under 1 bar, respectively. In particular, N-AC-600-2 and N-AC-600-3 materials show the highest uptakes of CO2 at 25 and 0 °C, respectively, which rank among the best porous carbon sorbents. The nitrogen-doping and porosity of the fabricated carbons have combined impact on CO2 adsorption. In addition, both excellent regenerability and high CO2/N2 selectivity were achieved, making these carbon materials promising candidates for large-scale CO2 adsorption.