Constructing highly active alloy-perovskite interfaces for efficient electrochemical CO₂ reduction reaction

The electroreduction of CO₂ through solid oxide electrolysis cells (SOEC) is considered as a promising technology for mitigating climate changes related to global warming. A SOEC system can effectively reduce polarization losses and best utilize process heat to electrolyze CO₂ to produce CO. However, this technology is hindered by the sluggish cathode kinetics, which is mainly due to the poor catalytic activity for the CO₂ reduction reaction. Herein, this work develops an A-site ordered layered perovskite oxide, (PrBa)_0.95Fe_1.6Ni_0.2Nb_0.2O_5+δ (PBFNN), as an efficient cathode catalyst for CO₂-SOEC. FeNi₃ nanoparticles are in situ generated on the surface of perovskite substrate after reduction, the resulting active alloy-perovskite interfaces between FeNi₃ and PBFNN substrate can effectively promote the CO₂ reduction reaction (CO₂RR). The nanoparticles and abundant oxygen vacancies of FeNi₃-PBFNN significantly enhance CO₂ adsorption and activation, which is verified by the CO₂-temperature programmed desorption measurement and density functional theory calculations. Distribution of relaxation time analysis and electrochemical performance characterization indicate that this interface engineering at nanoscale greatly improves the catalytic activity of the cathode for CO₂RR.