Improvement of graphitization of isotropic carbon by Al2O3 formed from aluminium chelate compound

For improving the graphitization of isotropic carbon, ethyl acetoacetate al uminium diisopropoxide and aluminium oxide were used as catalysts. Their ef fect was investigated and the corresponding mechanism was discussed. The re sults showed that the isotropic carbon was graphitized greatly by the addit ion of ethyl acetoacetate aluminium diisopropoxide when the heat-treatment temperature was over 1850 degrees C, and slightly by the addition of alumin ium oxide at 1900 degrees C. The mechanism is considered to be that the alu minium compound formed from ethyl acetoacetate aluminium diisopropoxide rea cted with C to give Al4C3 and with increasing temperature the Al4C3 decompo sed to form Al(g) and C-Gr which was graphitized. Additionally, Al-containi ng gases and CO2(g) were the reactants of the reaction between aluminium ox ide and C. This showed only a little effect on the graphitization of isotro pic carbon when the heat-treating temperature was 1900 degrees C. (C) 1999 Elsevier Science Ltd. All rights reserved.