Solid-State Electrolyte Catalysis for Methane and Oxygen Synthesis. Annual Report No. 1, August 1, 1987-August 31, 1988

摘要

The performance of an oxygen-ion-conducting electrochemical cell for enhancing the conversion of CO2 to CH4 and O2 has been investigated. The approach involves the use of an oxide-ion conducting solid electrolyte in an electrochemical reactor configuration to carry out surface catalysis for the breakage of carbon-oxygen bonds as well as formation of carbon-hydrogen bonds, and removal of oxygen by ionic migration through the solid electrolyte. Experiments with CO2-H2 reaction mixtures on Ni and Pt catalyst electrodes in contact with a zirconia solid electrolyte have shown that CO2 is converted to CH4 at an increased rate under DC biased conditions. The solid state electrochemical approach resulted in enhancements of up to two orders of magnitude in the methanation rate of CO2, despite the use of a configuration that was not optimized. The mechanistic sequence of the reaction involves the formation of CO, which is reduced to Cs, which is then hydrogenated to CH4.