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Porous carbons derived from polysaccharides (cellulose, chitosan, and alginic acid) have been prepared by heat treatment under N2 atmosphere and activated at high temperature under ammonia gas atmosphere. The CO2 adsorption capacities of prepared porous carbon materials and their dependence on the surface area and pore volume were investigated. The surface area of pristine carbon from cellulose, chitosan, and alginic acid at 800 °C was measured as 406.5, 206.8, and 258.2 m2/g with the pore volume of 0.27, 0.14, and 0.15 cm3/g, respectively. The surface area and pore volume of carbons derived from cellulose, chitosan, and alginic acid further increased up to 976.6, 883.4, and 1031.9 m2/g and 0.54, 0.45, and 0.65 cm3/g, respectively, after the activation at high temperature under ammonia gas environment. The CO2 adsorption capacities of pristine carbons were measured as high as 1.85 mmol/g and further increased up to 2.44 mmol/g by ammonia activation.

Microporous and mesoporous carbons have been prepared by a soft template method using 2,2′-biphenol as a precursor. The porosity of carbons could be controlled by varying the amount of block copolymer used as a soft template and the specific surface areas measured were as high as 648 m2/g with a pore volume of 0.43 cm3/g. The surface areas of prepared carbons were further increased up to 1778 m2/g with a pore volume of 0.75 cm3/g after heat treatment under ammonia gas environment. Although the prepared pristine carbons had lower surface areas than commercial activated carbon, they exhibited higher carbon dioxide (CO2 ) adsorption capacity. The CO2 adsorption capacity of ammonia-activated carbons further increased up to 2.98 mmol/g at ambient temperature and pressure.