Platinum-Decorated Ceria Enhances CO₂ Electroreduction in Solid Oxide Electrolysis Cells

CO₂ electroreduction by solid oxide electrolysis cells (SOECs) can not only attenuate the greenhouse effect, but also convert surplus electrical energy into chemical energy. The adsorption and activation of CO₂ on the cathode play an important role in the SOEC performance. La_0.6 Sr_0.4 Co_0.2 Fe_0.8 O_3-δ -Ce_0.8 Sm_0.2 O_2-δ (LSCF-SDC; SDC=samarium-doped ceria) is a promising SOEC cathode. However, its electrocatalytic activity still needs to be improved. In this study, Pt/SDC interfaces are constructed by decorating Pt nanoparticles onto the SDC surface. Electrochemical measurements indicate that the polarization resistance of the SOEC is decreased from 0.308 to 0.120 Ω cm² , and the current density is improved from 0.913 to 1.420 A cm^-2 at 1.6 V and 800 °C. Physicochemical characterizations suggest that construction of the Pt/SDC interfaces increases the oxygen vacancy concentration on the cathode and boosts CO₂ adsorption and dissociation, which leads to enhanced CO₂ electroreduction performance in SOECs.