Abstract: A sol-gel process was employed to prepare SiC precursors, using tetraethyl orthosilicate (TEOS) and sucrose as raw materials. And oxalic acid, ferric nitrate, and nickel nitrate were added respectively as catalyst for hydrolysis and polymeration reactions. The effects of catalyst, reaction temperature, and reaction time on the gel formation were studied. The results showed that ferric nitrate was optimal for gel formation. SiC of 133 m2·g-1 was obtained by further carbonthermal reduction of the xerogel from the sol-gel system involved ferric nitrate, at 1350 ℃ in an Ar flow for 10 h. Such SiC was then used as catalyst support for CO oxidation. Wet impregnation method was adopted to obtain Pt/SiC catalyst. The as-prepared Pt/SiC catalyst showed good activity and stability for CO oxidation. It was also found that its performance could be improved significantly with the synergistic action of Ni promoter.

Key words: Sol-gel, Silicon carbide, High surface area, CO oxidation, Support