Understanding of CO2 electrochemical reduction reaction process via high temperature solid oxide electrolysers

Abstract

The CO2 electrochemical reduction via SOEC was studied for a range of cathode materials in various operational conditions. The influences of the fuel gas composition, operating potential and temperature on cathode behavior are discussed and compared on different cathodes. The dissociative adsorption and surface diffusion of active species from CO2 reduction reaction was found to contribute dominantly to the LSCM-based cathode working in CO2-CO mixtures. Efforts were also made to obtain a high performance and durable cathode for high temperature CO2 electrolyser by employing a gradient LSCM-YSZ cathode and by adopting wet impregnation in cathode preparation. The latter was to more effective in enhancing the cathode electro-catalytic activity. A competitive cathode to Ni-YSZ cermet was fabricated by infiltrating 0.5wt% Pd and GDC into porous LSCM and YSZ layers.