Efficient carbon dioxide electrolysis based on ceria cathode loaded with metal catalysts

Fluorite-type heterogeneous catalyst ceria is a mixed conductor and widely used as a hydrocarbon-fueled solid oxide fuel cell anode because of its advantage of anti-carbon deposition, redox stability, and thermal compatibility. However, the electrocatalytic activity of a ceria cathode is limited for the catalysis of electrochemical oxidation or reduction reactions. In this work, catalytic-active iron and nickel catalysts are loaded onto a ceria cathode via an infiltration method to enhance electrode performance. Direct electrolysis of carbon dioxide is performed on ceria cathodes loaded with iron and nickel catalysts in solid oxide electrolyzers, respectively. The polarization resistance of symmetrical cells and electrolysis cells loaded with nickel and iron catalysts is largely improved in comparison with the bare ceria. The current efficiencies for carbon dioxide electrolysis for the iron- and nickel-loaded cathodes are 76 and 80 % at 2.0 V and 800 °C, respectively, approximately 25 % higher than that for the bare ceria cathode.