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

[Display omitted] •N-doped porous carbons were synthesized from K2CO3 activation of polyacrylonitrile fiber.•Fibrous structures are mostly maintained for as-synthesized carbons.•The obtained carbon exhibits high CO2 uptake, 5.84 mmol/g at 0 °C and 1 bar.•The adsorbents also exhibit various good CO2 adsorption properties.•Combined effect of textual properties and N functionalities decides CO2 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 CO2 adsorption and separation process. Herein, N-doped porous carbon with an abundance of nitrogen groups (N doping > 15 wt%), a preservedfibril morphology, aBET surface area of 2434 m2/g together with a pore volume of 1.23 cm3 g−1 was produced from polyacrylonitrile fiber via chemical activation of K2CO3. The optimal porous carbon fiber sample has CO2 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 CO2 over N2. 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 CO2 capture performance.