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

Abstract

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)0.95Fe1.6Ni0.2Nb0.2O5+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.