Effect of transition and non-transition metals during the synthesis of carbon xerogels

The aim of this present study was to synthesis transition and non-transition metal-doped carbon xerogels by soft templating approach using resorcinol, p-cresol and formaldehyde as the organic precursors along with poly (ethylene oxide)/poly (propylene oxide)/poly (ethylene oxide) (PEO/PPO/PEO) triblock copolymers and cetylpyridinium chloride as the template materials. The effects of metal ions on the surface area as well as the morphology of the resultant carbon materials were evaluated by using metal ions, such as, manganese, cobalt, copper, calcium, strontium and barium during the formation of RF (resorcinol-formaldehyde) gel. Resorcinol/formaldehyde molar ratio (R/F molar ratio), initial pH of the resol solution and percentage of the metal salts with respect to resorcinol (w/w) were also chosen as effective independent experimental variables. For non-transition metals the highest BET surface area (968 m(2)/g) was obtained for 5% strontium at pH 8 in the presence of cetylpyridinium chloride as the surfactant, whereas manganese doped carbon xerogel give the highest surface area (1038 m(2)/g) among the all transition metal doped carbon materials under the optimum condition of 0.35 (1:2.85) resorcinol/formaldehyde molar ratio, initial pH of resol solution 3.0, and 11% (w/w) Mn2+ salt. The materials were characterized by FE-SEM, HR-TEM, pore size and surface area analysis. (C) 2010 Elsevier Inc. All rights reserved.