Hydrothermal synthesis of nitrogen-doped ordered mesoporous carbon via lysine-assisted self-assembly for efficient CO 2 capture.

Nitrogen-doped ordered mesoporous carbons (NOMCs) were synthesized by single-step hydrothermal self-assembly using F127 as a soft template, hexamine as a formaldehyde source, l-lysine as a polymerization catalyst, and 3-aminophenol as both carbon and nitrogen sources. The microstructure of the NOMCs was characterized by XRD, N 2 adsorption/desorption, TEM, FTIR, and XPS. The results indicated that the obtained NOMCs exhibited a large specific surface area, uniform pore size distribution and highly ordered 2-D hexagonal mesostructure ( P 6 mm ). Besides, the nitrogen was uniformly doped into the carbon framework in the form of various nitrogen species. The adsorption isotherms of CO 2 and N 2 were also determined and could be well fitted by a DSL model. The capture capacity of CO 2 was affected by both the nitrogen content and mesostructure of the adsorbents. Overall, NOMC-L-0.5 displayed excellent CO 2 capture capacity (0 °C, 3.32 mmol g -1 ; 25 °C, 2.50 mmol g -1 ), and still demonstrated great regenerability with only 2% loss after several CO 2 adsorption/desorption cycles. Moreover, the CO 2 /N 2 selectivity calculated by IAST was as high as 43.2 at 25 °C in a typical composition of flue gas (binary mixtures with 15% CO 2 ). The superior adsorption performance enables NOMCs to be a promising CO 2 adsorbent in practical applications.