Ca/Cu Co-doped SmFeO3as a Fuel Electrode Material for Direct Electrolysis of CO2 in SOECs

The electrochemical conversion of CO(2)to CO by using solid oxide electrolysis cell (SOEC) is an attractive technology for sustainable utilization of greenhouse gas to chemicals. In this work, Ca and/or Cu doped SmFeO(3)perovskite materials in the form of Sm1-xCaxFe1-yCuyO3-delta(x= 0,y= 0;x= 0.1,y= 0;x= 0,y= 0.1;x= 0.1,y= 0.1) are evaluated as SOEC fuel electrode for direct electrolysis of CO2. The Ca and Cu co-doped sample Sm0.9Ca0.1Fe0.9Cu0.1O3-delta(SCFCO) presents the highest electrical conductivity value of 15.18 S cm(-1)among all of the samples under CO(2)atmosphere at 700 degrees C. The electrochemical impedance spectroscopy analysis reveals that the CO(2)dissociative adsorption and charge transfer of Ca and Cu co-doped fuel electrode are significantly enhanced, resulting in the greatly decrease in polarization resistance compared with that of the undoped sample. The current density of an electrolyte-supported single cell with the SCFCO fuel electrode reaches as high as 1.20 A cm(-2) at the applied voltage of 1.5 V and 800 degrees C, which is 60% higher than that of the SmFeO3-delta fuel electrode. Furthermore, the cell shows an impressive stability for the durability test, indicating the excellent electrocatalysis performance and coking tolerance of SCFCO as a promising fuel electrode material for direct electrolysis of CO2.