CO and CO2 methanation was investigated over Ni catalysts supported on different supports such as Al2O3, SiO2, TiO2, CeO2, and ZrO2. Among them, Ni/CeO2 was determined to be the most active for CO and CO2 methanation. These catalytic activities increased with increasing surface area of CeO2. To increase the specific catalytic activity for CO and CO2 methanation, various Ni-CeO2 catalysts with different Ni contents were prepared using co-precipitation method. The optimum Ni content was determined for both reactions. The prepared catalysts were characterized with inductively coupled plasma-atomic emission spectroscopy, N-2 physisorption, temperature-programmed reduction, temperature-programmed desorption, and X-ray diffraction. The high Ni dispersion and strong CO2 adsorption appeared to be responsible for the high catalytic activity for CO and CO2 methanation. This Ni-CeO2 can be applied to the low-temperature CO and CO2 methanation reactor to achieve high single-pass conversions of CO and CO2. (C) 2016 Elsevier B.V. All rights reserved.