Japanese Patent No. 6059140 has been issued (Novel Catalyst Mixtures). Electrochemical devices comprising electro-catalyst mixtures include at least one Catalytically Active Element and, as a separate constituent, one Helper Catalyst. The electrocatalysts can be used to increase the rate, modify the selectivity or lower the overpotential of chemical reactions. These electrocatalysts are useful for a variety of chemical reactions including, in particular, the electrochemical conversion of CO2.