The key challenge for CO2 methanation, an eight-electron process under kinetic limitation, relies on the design of non-noble metal catalysts so as to achieve high activity at low reaction temperatures. In this work, four Ni-based catalysts with different supports were prepared and tested for CO2 methanation at 250-550 degrees C in a fixed bed quartz reactor and further characterized to reveal the structure-function relationship. The Ni-based catalysts followed an activity order of Ni/CeO2 > Ni/Al2O3 > Ni/TiO2 > Ni/ZrO2, especially at temperatures lower than 350 degrees C. H-2-TPR and TPD results indicated that the interaction between nickel and support was strong and the metallic nickel was well dispersed in the Ni/Al2O3 catalyst, while more amount of CO2 was adsorbed on the weak basic sites in the Ni/CeO2 catalyst. By establishing the correlation between the catalytic performance and the catalyst structure, it was found that the Ni nanoparticles and basic support serve as H-2 and CO2 active centers respectively and cooperatively catalyze CO2 methanation, resulting in high low-temperature reaction activity. [GRAPHICS] .