Sulfonated carbon catalysts were prepared by sulfonation of carbonized catkins from willow under different
sulfonated conditions. Such materials were characterized by SEM, EDS, FTIR and TGA. The results indicated
that sulfonated conditions might influence the acid density of the sulfonated carbon catalysts, but did not
influence the microtubular structure. These sulfonated carbon catalysts exhibited high acid capacity, good
thermal stability and better catalytic activity for the glycerol esterification. With a molar ratio of acetic acid to
glycerol of 5:1, a catalyst amount of 5 wt.% and a reaction temperature of 393 K for 2 h, glycerol was almost
completely transformed into a mixture of glycerol esters including monoacetate, diacetate and triacetate.
Controlling of acid density of the catalysts and reaction conditions could obtain highly desired products.
Meanwhile, the hydrophobic property of these sulfonated carbon catalysts led to some tolerance to water.
Moreover, excellent reusability of the catalyst was also confirmed by repeated experiments.