ZrO2 was prepared via precipitation method and then used as the support of Mo catalysts for CO methanation in the presence of H2S. The impact of post precipitation procedures of ethanol-washing and digestion(aging in hot ethanol)on the evolution of textural, structural and morphological properties of zirconia was investigated. The physicochemical properties of ZrO2 supports and MoO3/ZrO2 catalysts were characterized by nitrogen adsorption-desorption, XRD, TEM and XPS. The results indicated that the post precipitation treatment was an effective means to achieve zirconia support with large specific surface area, and uniform and small particle size. The catalytic performance of the MoO3/ZrO2 catalysts was improved with ZrO2 prepared by digesting at high temperature, which could be related to the degree of sulfidation of Mo species and the enhancement of dispersed MoS2 active sites. © 2017, Chemical Industry Press. All right reserved.