Enhancing cathode performance for CO_2 electrolysis with Ce_(0.9)M_(0.1)O_(2-δ)(M=Fe,Co, Ni) catalysts in solid oxide electrolysis cell

Electrochemical conversion with solid oxide electrolysis cells is a promising technology for CO_2 utilization and simultaneously store renewable energy. In this work, Ce_(0.9)M_(0.1)O_(2-δ)(CeM, M=Fe, Co, Ni) catalysts are infiltrated into La_(0.6) Sr_(0.4) Cr_(0.5_ Fe_(0.5) O_(3-δ)–Gd_(0.2) Ce_(0.8) O_(2-δ)(LSCr Fe-GDC) cathode to enhance the electrochemical performance for CO2 electrolysis. Ce Co-LSCr Fe-GDC cell obtains the best performance with a current density of 0.652 A cm-2, followed by Ce Fe-LSCr Fe-GDC and Ce Ni-LSCr Fe-GDC cells with the value of 0.603 and 0.535 A cm~(-2), respectively, about 2.44, 2.26 and 2.01 times higher than that of the LSCr Fe-GDC cell at1.5 V and 800 °C. Electrochemical impedance spectra combined with distributions of relaxed times analysis shows that both CO_2 adsorption process and the dissociation of CO_2 at triple phase boundaries are accelerated by Ce M catalysts, while the latter is the key rate-determining step.