The effect of graphitization catalyst on the structure and porosity of SiC derived carbons

A number of carbide-derived carbon (CDC) samples were synthesized through the reaction between alpha-SiC and gaseous chlorine at temperatures 900, 1000 and 1100 degrees C and by varying the amount of catalyst. The chlorides of Cool), Ni(II) and Fe(III) were used as catalytic additives in a range of concentration of 0.1-5 wt%. The structural differences of the obtained carbons were studied by low-temperature nitrogen adsorption, X-ray diffraction and Raman spectroscopy. Results showed that porosity, specific surface area and graphitization degree of the CDC materials is a function of chlorination temperature and catalyst concentration, which agrees with previous results. It was shown that the catalytic graphitization only weakly influences the L. value of the crystallites, which according to the Raman scattering is similar to 4-5 nm in both the highly disordered SiC derived carbons and in fully graphitic carbons made from SiC containing 15 wt% of surface-contacted Co-Ni-Fe catalyst. The surface area of the CDC materials can be controlled in the range of 300-1350 m(2) g(-1), depending on the amount of catalysts used. (C) 2008 Elsevier Ltd. All rights reserved.