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

For improving the graphitization of isotropic carbon, ethyl acetoacetate aluminium diisopropoxide and aluminium oxide were used as catalysts. Their effect was investigated and the corresponding mechanism was discussed. The results showed that the isotropic carbon was graphitized greatly by the addition of ethyl acetoacetate aluminium diisopropoxide when the heat-treatment temperature was over 1850 degrees C, and slightly by the addition of aluminium oxide at 1900 degrees C. The mechanism is considered to be that the aluminium compound formed from ethyl acetoacetate aluminium diisopropoxide reacted with C to give Al4C3 and with increasing temperature the Al4C3 decomposed to form Al(g) and C-Gr which was graphitized. Additionally, Al-containing gases and CO2(g) were the reactants of the reaction between aluminium oxide and C. This showed only a little effect on the graphitization of isotropic carbon when the heat-treating temperature was 1900 degrees C. (C) 1999 Elsevier Science Ltd. All rights reserved.