Enhanced CO2 methanation activity over Ni/CeO2 catalyst by one-pot method

Carbon dioxide hydrogenation for value-added chemicals has been regarded as a promising way for CO 2 utilization. This paper describes the preparation of Ni/CeO 2 catalysts derived from Ce-MOF precursor by impregnation or one-pot method and their application in carbon dioxide methanation. Various techniques were employed to characterize the prepared catalysts, including N 2 adsorption–desorption, X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (SEM), H 2 -temperature programmed reduction (H 2 -TPR), H 2 -temperature programmed desorption (H 2 -TPD) and CO 2 -temperature programmed desorption (CO 2 -TPD). The results showed that compared with commercial CeO 2 and CeO 2 prepared by precipitation, CeO 2 derived from Ce-MOF exhibited more oxygen vacancies and lower temperature reducibility, making it more beneficial for the adsorption and activation of CO 2 . Consequently, nickel supported on rod-shaped CeO 2 derived from Ce-MOF exhibited higher CO 2 conversion and methane selectivity at low temperatures. Furthermore, the Ni/CeO 2 −M-1 catalysts prepared by one-pot method showed superior activity since nickel could be partially incorporated into ceria lattice, leading to the formation of Ce 1-x Ni x O 2-y solid solutions and oxygen vacancies. The effect of nickel loading on the properties of the catalysts by one-pot method was also investigated, and the optimum Ni loading was 15 wt.% owing to the maximum number of oxygen vacancies being reached.