Adsorptivities of Extremely High Surface Area Activated Carbon Fibres for CH 4 and H 2

Abstract

Activated carbon fibres with extremely high surface areas (ACFs) were prepared by CO₂ re-activation using pitch-based ACFs having an original surface area of 1730 m²/g. The highest surface area of the re-activated ACFs was 2930 m²/g as determined from an α_S-plot analysis of the nitrogen adsorption isotherm measured at 77 K. The ACF with the highest surface area showed excellent adsorptivity towards supercritical CH₄ and H₂. The amounts of CH₄ and H₂ adsorbed were enhanced by 52% and 30%, respectively, as a result of re-activation.