CO2 hydrates may be more suitable for sequestration if they were formed inside the pore spaces of a solid. Sorption/desorption isotherms of CO2 in activated carbon with different amounts of water were collected in a temperature range of 275-281 K. The isotherms show an inflection point indicating that CO2-hydrates form in the pore spaces of the activated carbon, and the formation of CO2-hydrates leads to a high storage capacity of the activated carbon for CO2. However, the molar ratio of H2O/CO2 is far less than the theoretical value, which is attributed to the relatively high solubility of CO2 in water. (c) 2007 Elsevier B.V. All rights reserved.