An electrochemical device comprises an anode and a cathode. An electrocatalyst mixture is placed between said anode and cathode. The electrocatalyst mixture comprises at least one Catalytically Active Element and, separately, at least one Helper Catalyst comprising an organic molecule, an organic ion, or a mixture of organic molecules and organic ions. The electrocatalyst mixture electrochemically converts carbon dioxide to one or more carbonaceous reaction products via the reaction: CO2+2e−+2H+→carbonaceous reaction products, at overpotentials of 0.9 V or less.