Highly stable and efficient catalyst fabricated with in situ exsolved Co-Fe bimetallic nanoparticles anchored on (Ba0.9K0.1)0.9Co0.5Fe0.4Nb0.1O3-δ for CO2 electrolysis

Solid oxide electrolysis cells (SOECs), featuring high current density and Faradaic efficiency, have been extensively recognized for CO 2 electrolysis abilities. However, it is a challenge to find high performance electrode materials with excellent catalytic activity and preferable stability. Herin, hetero-structured perovskite with exsolved Co-Fe nanoparticles is developed via in - situ reduction of the (Ba 0.9 K 0.1 ) 0.9 Co 0.5 Fe 0.4 Nb 0.1 O 3- δ ((BK) 0.9 CFNb). The corresponding SOEC R-(BK) 0.9 CFNb/LSGM/LSCF achieves excellent electrochemical performance with a current density of 0.813 A cm −2 at 1.5 V and 800 °C, which is 30 % higher than the counterpart with untreated (BK) 0.9 CFNb cathode. Its high catalytic activity is attributed to electron feeding effect of in situ exsolved Co-Fe nanoparticles and enhanced CO 2 adsorption with high concentration of oxygen vacancies in perovskite substrate surface. Moreover, the R-(BK) 0.9 CFNb-cell shows much better stability than parent (BK) 0.9 CFNb-cell, which is ascribed to the structural anchoring of the alloy nanoparticles. This study provide an attractive strategy for the future development of SOECs.