Realizing Efficient Activity and High Conductivity of Perovskite Symmetrical Electrode by Vanadium Doping for CO2 Electrolysis.

Solid oxide electrolysis cells (SOECs) show significant promise in converting CO₂ to valuable fuels and chemicals, yet exploiting efficient electrode materials poses a great challenge. Perovskite oxides, known for their stability as SOEC electrodes, require improvements in electrocatalytic activity and conductivity. Herein, vanadium(V) cation is newly introduced into the B-site of Sr₂Fe_1.5Mo_0.5O_6-δ perovskite to promote its electrochemical performance. The substitution of variable valence V⁵⁺ for Mo⁶⁺ along with the creation of oxygen vacancies contribute to improved electronic conductivity and enhanced electrocatalytic activity for CO₂ reduction. Notably, the Sr₂Fe_1.5Mo_0.4V_0.1O_6-δ based symmetrical SOEC achieves a current density of 1.56 A cm^-2 at 1.5 V and 800 °C, maintaining outstanding durability over 300 h. Theoretical analysis unveils that V-doping facilitates the formation of oxygen vacancies, resulting in high intrinsic electrocatalytic activity for CO₂ reduction. These findings present a viable and facile strategy for advancing electrocatalysts in CO₂ conversion technologies.