Stable and Highly Dispersed Nickel Catalysts on Ce-Zr-O Solid Solutions for CO2 Methanation

To improve the low-temperature activity and anti-sintering ability of Ni-based catalyst for CO2 methanation, nickel catalysts supported on ZrO2, CeO2 and Ce-Zr-O solid solutions are prepared via citrate complexation-impregnation method, and characterized by BET, TPR, CO2-TPD, H-2-TPD, XRD, XPS, TEM and ICP. The relationship between the structure and catalytic performance is also investigated systematically. The results show that Ni/Ce0.2Zr0.8O2 catalyst exhibits the highest CO2 conversion of 71 % at 250 degrees C and the highest stability, which is mainly attributed to the high dispersion of active metal nickel and its small particle size. The optimized interaction between Ce-Zr-O solid solution and Ni is in favor of the high dispersion and the stability of Ni nanoparticles on the surface, and enhances the sintering resistance of Ni catalyst. In addition, the similar TOF values of catalysts in different supports indicate that for improving low-temperature activity of this system, the dispersion of Ni NPs is critical.