A detailed study has been conducted on the effects of carbon surface oxides and added potassium salts on the hydrogenolysis of carbon. Carbon surface oxides were decomposed and desorbed in the forms of CO and CO₂. The resulting surface carbons were much more reactive than the well crystallized carbons as measured by temperature-programmed reaction in 101 kPa H₂. The activation energies for CH₄ formation were estimated as 75-85 kJ/mole and they were about the same order of magnitude for Ni catalysed carbidic carbon hydrogenation. Added potassium salt accelerated the formation of CH₄ at low temperatures. It seems to be enhanced desorption of carbon surface oxides by the potassium-surface oxide interaction.