Preparation and catalytic performance of a carbon-based solid acid catalyst with high specific surface area

A carbon-based solid acid catalyst was prepared by incomplete carbonization of H ₃PO ₄-impregnated pulp fibers followed by sulfonation. XRD, FT-IR, BET, TGA, and acid density test were employed to characterize the structure and performance of the catalyst. Results showed that the catalyst was amorphous carbon composed of aromatic carbon sheets with -COOH, -OH and -SO ₃H groups. Previous impregnation with H ₃PO ₄ could promote porosity formation of the catalyst. The optimized carbonization temperature and time for the catalyst were 250 °C and 1.5 h. The -SO ₃H density and specific surface area for the catalyst prepared under the optimized conditions were 1.1 mmol g ^-1 and 118 m ² g ^-1, respectively. Compared to HZSM-5, Amberlyst-15 and previous reported carbon catalysts, the catalyst showed higher catalytic activity for transesterification of methyl acetate with n-butanol as hydrophobic reaction. The catalyst had good thermal stability, which could bear 200 °C without decomposition. The catalyst retained satisfactory catalytic activity for transesterification of methyl acetate after 8 reaction cycles.