Pore structure of carbons coated on ceramic particles

Pore structure of carbon coated on ceramic particles by carbonization of precursor in a powder mixture at 900degreesC was studied by focusing on the effects of substrate ceramics (MgO, TiO2 and various phases of Al2O3) and of carbon precursor (poly(vinyl alcohol) (PVA), poly(ethylene terephthalate) (PET) and hydroxyl propyl cellulose (HPC)). By dissolving substrate MgO particles, carbon coated was found to have a high BET surface area, more than 1000m(2)/g, which was almost the same as the value estimated from apparent surface area measured on carbon-coated MgO particles under the assumption of zero surface area of the substrate. The carbon separated was found to be rich in micropores from the analyses by DFT method and alpha(s) plot. The dependence of the BET surface area on the amount of carbon coated on TiO2 with a high surface area was the same for three carbon precursors, although the carbon yields from the precursors were slightly different. Porous Al2O3 substrates, gamma-Al2O3 as-received and that formed from Al(OH)(3) during carbonization, gave a high BET surface area, but dense Al2O3, alpha-Al2O3, gave a low surface area. (C) 2004 Elsevier Ltd. All rights reserved.