Hierarcal porous polystyrene-based activated carbon spheres for CO2 capture

Activated carbon spheres with high specific surface area and hierarcal porous texture were prepared from polystyrene-based macroreticular resin spheres by air pre-oxidization and steam activation. The as-prepared carbon spheres had a specific surface area of 1274.95 m 2 g − 1 , total pore volume of 1.09 cm 3 g − 1 and micropore volume of 0.47 cm 3 g − 1 . Moreover, these carbon spheres showed a hierarcal porous texture composed of ultrafine micropores (0.5-1 nm), micropores (1–2 nm), mesopores (10–50 nm) and macropores (50–100 nm). A CO 2 adsorption capacity of 2.82 mmol g − 1 for carbon spheres can be obtained at 30 ℃ and 1 atm. Further, after introducing nitrogen-containing functional groups by gaseous ammonia at 600 ℃, these carbon spheres exhibited a high CO 2 adsorption capacity of 3.2 mmol g − 1 . In addition, excellent cyclic stability, low hygroscopicity and regenerability temperature suggested these carbon spheres were favorable for CO 2 capture.