Hierarcal porous polystyrene-based activated carbon spheres for CO2 capture

Abstract 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 m2 g− 1, total pore volume of 1.09 cm3 g− 1 and micropore volume of 0.47 cm3 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 CO2 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 CO2 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 CO2 capture.