Pure Ni nanoparticles with ultrafine size (2.3 ± 0.4 nm) embedded on rGO present ultrahigh catalytic activity (1600 mA mg-1), excellent stability (1020 mA mg-1 retained after 1000 cycles), and a saturation concentration (4 M) of methanol for methanol oxidation reactions, which is better than that of all previously reported Ni-based catalysts.