The Ni nanoparticles of narrow size distribution supported on silica were prepared using different alkanol solvents (ethanol, ethylene glycol and glycerol) by wet impregnation method. The mean size of Ni nanoparticles can be tuned using alkanol as delivery conveyors and removable carbon templates. Compared with conventional catalysts prepared using aqueous solution, the as-obtained catalysts owned smaller and uniform size of metal particle due to confinement effect of carbon templates, especially ethylene glycol and glycerol as solvent (6-8 nm). It was found catalytic activity was dependent on the size of the metal particles. The overall scheme of POM was determined by surface valence states of nickel particles which were affected by nanoparticles size. Inspiringly, the Ni/SiO2 catalyst prepared by glycerol solvent was proved to be more active, giving CH4 conversion of 94%, CO selectivity of 88% due to the higher reducibility, higher metal dispersion and more unsaturated surface atoms contributed by smaller metal nanoparticles. (C) 2016 Published by Elsevier Ltd.