We confirmed here that the catalyst preparation methodologies have a significant effect on the activity and stability of Ni/SiO2 catalyst for methanation of syngas (CO + H-2). Catalyst characterizations using X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H-2-TPR) and transmission electron microscope (TEM) were performed to investigate the structure and performance of the catalysts. The activity and stability of catalysts prepared by thermal decomposition and dielectric-barrier discharge (DBD) plasma decomposition of nickel precursor were compared. The plasma decomposition results in a high dispersion, an enhanced interaction between Ni and the SiO2 support, as well as less defect sites on Ni particles. Enhanced resistance to Ni sintering was also observed. In addition, the plasma prepared catalyst effectively inhibits the formation of inactive carbon species. As a result, the plasma prepared catalyst exhibits significantly improved activity with enhanced stability. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.