Sr(Ti_0·3Fe_0.7)O_3−δ-based perovskite with in-situ exsolved Fe–Ru nanoparticles: A highly stable fuel electrode material for solid oxide electrochemical cells with efficient electrocatalytic CO₂ reduction ability and preferential selectivity

The development of solid-oxide cells requires fuel electrodes capable of promoting highly catalytic activities for CO₂ electrochemical reduction (CO₂R). This study develops a fuel electrode material, Sr(Ti_0·3Fe_0·63Ru_0.07) O_3-δ (STFR) perovskite, enhance with in-situ exsolved Fe–Ru nanoparticles (STFR–FeRu), demonstrating excellent electrochemical catalytic activity for CO₂R, considerable stability, and high selectivity for CO₂ electrolysis. Notably, the study discovered for the first time that STFR–FeRu exhibits significantly enhanced catalytic activity in a CO₂-containing atmosphere compares to that in hydrogen-based fuels. At 800 °C and 1.3 V, La_0·8Sr_0.2Ga_0.8Mg_0·2O_3-δ electrolyte-supported cells with STFR–FeRu fuel electrode, for direct CO₂ electrolysis, realizes a current density of 1.77 A cm⁻². This current density is 50 % higher than that of H₂O electrolysis under the same conditions. Additionally, the cell achieves a current density of 1.54 A cm⁻² for CO₂–H₂O co-electrolysis, with a high CO₂ electrolysis selectivity (CO concentration exceeding 60 % in the electrolysis products).