Performance of Cerium Oxides from Different Preparation Methods for Desulfurizing Hot Coal Gas

Abstract

Four CeO2 samples were prepared by pyrolysis of cerium hydroxide, cerium nitrate, cerium oxalate, and cerium perchlorate. The structures of CeO2 samples were characterized by means of X-ray diffraction and nitrogen adsorption-desorption. Temperature-programmed reduction and thermogravimetry tests were carried out to evaluate the reduction and sulfurization behaviors of the CeO2 samples. The results indicate that the samples, prepared from different precursors, have larger surface areas and pore specific volumes, smaller average crystallite sizes, and better reducibilities (except the sample from cerium perchlorate) than the CeO2 reagent. The sulfurization performances of CeO2 samples are directly correlated with the reduction degrees of CeO2 samples. Compared with fresh CeO2 samples, reduced ones have better sulfurization performances. Among the four CeO2 samples, the one prepared from cerium nitrate, with the best reducibility, exhibits the best performance in sulfurization.