The hydrogenation of C, CO, and CO2 has been studied on polycrystalline cobalt foils using a combination of UHV studies and atmospheric pressure reactions in temperature range from 475 to 575 K at 101 kPa total pressure. The reactions produce mainly methane but with selectivities of 98, 80, and 99 wt% at 525 K for C, CO, and CO2, respectively. In the C and CO2 hydrogenation the rest is ethane, whereas in CO hydrogenation hydrocarbons up to C4 were detected. The activation energies of methane formation are 57, 86, and 158 kJ/mol from C, CO, and CO2, respectively. The partial pressure dependencies of the CO and CO2 hydrogenation indicate roughly first order dependence on hydrogen pressure (1.5 and 0.9), negative first order on CO (-0.75) and zero order on CO2 (-0.05). Post reaction spectroscopy revealed carbon deposition from CO and oxygen deposition from CO2 on the surface above 540 K. The reduction of cobalt oxide formed after dissociation of C-O bonds on the surface is proposed to be the rate limiting step in CO and CO2 hydrogenation.