Tailoring the textural properties of activated carbon xerogels by chemical activation with KOH

11 pages, 10 figures, 3 tables.-- Printed version published Nov 1, 2008.Resorcinol–formaldehyde xerogels synthesised with different resorcinol/sodium carbonate molar ratios were chemically activated either after drying or after drying and pyrolysis, using potassium hydroxide. It was found that organic (i.e. dried) and carbon (i.e. pyrolysed) xerogels behave differently when subjected to chemical activation. In the case of carbon xerogels, the increase in the microporosity takes place without any significant modification to the meso/macroporosity formed during the synthesis step, leading to micro–mesoporous or micro–macroporous materials with a larger micropore volume. Furthermore, control of the microporosity is possible because its development depends on the amount of KOH used. However, when organic xerogels are activated, mainly microporous materials with BET specific surface areas of up to 2000 m2 g−1 are obtained, there hardly remaining any of the meso/macroporosity formed during the gel synthesis. Thus, the combination of different synthesis conditions and chemical activation with potassium hydroxide allows the textural properties of carbon xerogels to be tailored at both micropore and meso/macropore levels.L.Z. acknowledges the support received from the CSIC I3P Programme cofinanced by the European Social Fund. N.J. is grateful to the F.R.S.-F.N.R.S. (Belgium) for a postdoctoral fellowship. The Belgian authors thank the Fonds de Bay, the Fonds de Recherche Fondamentale Collective, the Ministère de la Région Wallonne and the Interuniversity Attraction Pole (IAP) for their financial support, and acknowledge the involvement of their laboratory in the Network of Excellence FAME of the European Union Sixth Framework Program.Peer reviewe