Sulfur-resistant methanation over MoO3/CeO2–ZrO2 catalyst: Influence of Ce-addition methods

In this paper, Ce0.2Zr0.8O2 composite supports were prepared by different Ce-addition methods including impregnation of cerium (CeZr-imp), impregnation of citric acid and cerium (CeZr-CA) simultaneously and deposition precipitation method (CeZr-DP), respectively. The as-prepared supports were applied to prepare 10 wt% MoO3/Ce0.2Zr0.8O2 catalysts for sulfur-resistant methanation. The N2 adsorption/desorption, X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron (XPS), temperature-programmed reduction by hydrogen (H2-TPR) were undertaken to get textural properties, morphological information and structures of the catalysts. The results showed that MoO3 was highly dispersed on the surface of these three supports and Ce was mostly of coexisted in Ce4+/Ce3+ redox pairs. Compared with Mo/CeZr-imp, the CO conversion increased by 10% and 15% for Mo/CeZr-CA and Mo/CeZr-DP, respectively. This was mainly attributed to the larger specific surface area, Ce3+concentration and content of active MoS2 on the surface of catalysts.