Polyacrylonitrile-derived nitrogen enriched porous carbon fiber with high CO2 capture performance

• N -doped porous carbons were synthesized from K 2 CO 3 activation of polyacrylonitrile fiber. • Fibrous structures are mostly maintained for as-synthesized carbons. • The obtained carbon exhibits high CO 2 uptake, 5.84 mmol/g at 0 °C and 1 bar. • The adsorbents also exhibit various good CO 2 adsorption properties. • Combined effect of textual properties and N functionalities decides CO 2 uptake. Carbon dioxide capture and storage are considered a creative strategy for eliminating the catastrophic effect of global warming. The main concept in the present paper is to prepare nitrogen (N)-doping microporous carbon fibers and investigate their CO 2 adsorption and separation process. Herein, N -doped porous carbon with an abundance of nitrogen groups (N doping > 15 wt%), a preserved fibril morphology, a BET surface area of 2434 m 2 /g together with a pore volume of 1.23 cm 3 g −1 was produced from polyacrylonitrile fiber via chemical activation of K 2 CO 3 . The optimal porous carbon fiber sample has CO 2 adsorption capacity of up to 3.83 and 5.84 mmol g −1 at 25 and 0 °C under 1 bar, respectively, a fast adsorption rate and high selectivity of the CO 2 over N 2 . It has been found that the maintained fibrous morphology, the micro–mesoporous structure, and plentiful basic N -containing functionalities within the carbon framework all contribute to the outstanding CO 2 capture performance.