Metal-supported solid oxide electrolysis cell for direct CO2 electrolysis using stainless steel based cathode

Abstract

Solid oxide electrolysis cells (SOECs) are efficient devices to electrochemically convert CO2 to value-added chemicals, providing a competitive technology to realize carbon neutrality. Herein, a highly efficient and robust metal-supported SOEC is fabricated by bilayer tape-casting and infiltration method for direct CO2 electrolysis. A porous 430 stainless steel framework coated with nanoscale Sm0.2Ce0.8O2-δ (SDC) particles acts as the support and cathode, where the CO2 reduction reaction has been enhanced with the fast conduction of electrons from 430 framework to SDC electrocatalysts. Compared with the traditional cermet- and ceramic-supported SOECs, this metal-supported SOEC exhibits redox stability, minimal ohmic loss and high conductivity. Besides, an enlarged specific surface area and enhanced CO2 adsorption property of the cathode are obtained. The metal-supported SOEC with SDC infiltrated 430 cathode shows excellent current densities at 1.5 V, e.g., 2.13 A cm−2 at 850 °C and 1.38 A cm−2 at 800 °C. Meanwhile, short-term test under various applied voltages and Raman spectra have demonstrated this metal-supported SOEC is quite stable and free from coke deposition. Overall, this novel metal-supported SOEC could be a promising configuration for direct CO2 electrolysis.