Reduction of CO/sub 2/ to methanol and methane by photo and dark reactions on semiconductor and metal electrodes. Annual report, February 15, 1986-February 28, 1987

The electrochemical reduction of aqueous CO/sub 2/ was studied using Ru cathodes. The rate of methane formation is controlled by temperature, electrolyte pH, and impurities in the electrolyte. Electrode surfaces are deactivated at t greater than 80 C by formation of surface carbon. Methane formation is observed for potentials negative of -0.40V (SCE) at pH 4.0- is a poison for the methane reaction.