Nitrogen and sulfur co-doped microporous carbon prepared by a couple of activating and functionalized reagents for efficient CO2 capture and selective CO2/CH4 separation

Abstract

The increasing global warming and energy shortage have stimulated the worldwide explorations into effective adsorbents for the applications in the carbon dioxide capture and nature gas uprating. It is always a challenge in solving the problem of “trade-off” effect between gas adsorption capacity and selectivity. In this work, we provide a simple, green and cost-effective route to synthesize N, S co-doped microporous carbon adsorbent, selecting anthracite as carbon source, Na2S2O3 and NaNH2 as a couple of activating and functionalized reagents. The resultant carbon adsorbent exhibits a well-developed microporosity structure and a desirable functional heteroatoms series doping. The synergistic effect of these properties on carbon endows a high CO2 adsorption capacity (3.73 mmol g−1) and a good selectivity (7.80,7.03, 5.58, 4.93 and 4.40) for binary CO2/CH4 mixture (10/90, 15/85, 30/70, 40/60 and 50/50) separation at ambient conditions. The effective dynamic breakthrough behavior further demonstrates its adaptability in commercial applications. This work has developed a promising solution for converting anthracite into a high-value product for environmental and energy applications.