In Situ Exsolution of Core‐Shell Structured NiFe/FeOx Nanoparticles on Pr0.4Sr1.6(NiFe)1.5Mo0.5O6‐δ for CO2 Electrolysis

Abstract Solid oxide electrolysis cells (SOECs) have potential for efficient conversion of CO 2 to valuable chemical fuels at low cost. However, the performance and commercial viability of the existing SOECs is still hindered by the poor durability and electro‐catalytic activity of the cathode for CO 2 electrolysis. Here, the findings in preparation and characterization of a Ni‐free SOEC cathode materials composed of a Pr 0.4 Sr 1.6 (NiFe) 1.5 Mo 0.5 O 6‐δ (PSNFM) double perovskite matrix decorated with exsolved core‐shell structured NiFe/FeO x (NFA@FeO) nanoparticles are reported. A single cell with the PSNFM‐NFA@FeO cathode demonstrates a high current density of 1.58 A cm −2 for CO 2 electrolysis at a cell voltage of 1.4 V at 800 °C. The excellent electro‐catalytic activity of PSNFM‐NFA@FeO is attributed to the in situ exsolved NFA@FeO nanoparticles and the additional oxygen vacancies generated within the PSNFM substrate, creating plentiful NFA@FeO/PSNFM interfaces active for CO 2 adsorption and electrolysis. Moreover, the FeO shell on the NFA also contains a lot of oxygen vacancies, which can effectively extend the active sites from the NFA@FeO/PSNFM interfaces to the entire surface of the NFA@FeO nanoparticles, greatly enhancing the kinetics of adsorption, dissociation, and reduction of CO 2 .