Voltage-driven reduction method to optimize in-situ exsolution of Fe nanoparticles at Sr2Fe1.5+xMo0.5O6-δ interface

Improving the catalytic activity of perovskite electrodes by loading metal nanoparticles through interface engineering is one of the research hotspots in the field of CO2 electrolysis in solid oxide electrolytic cell (SOEC). The challenge is to improve the stability and carbon resistance of the metal-oxide interface while reducing time costs and improving scalability. We used applied voltage-driven reduction and non-stoichiometric doping to make Fe nanoparticles uniformly and firmly anchored on the surface of Sr2Fe1.5+xMo0.5O6-δ (SF1.5+xM, x = 0, 0.025, 0.05, 0.075, 0.1) within 180 s, optimized the distribution of Fe nanoparticles on the surface of SF1.5+xM, and thus constructed a metal-oxide interface with high activity and high stability, effectively preventing the sintering and carbon deposition of metal particles. When the electrode composition is SF1.575 M, the CO yield is 4.0 mL·min-1·cm-2, while the polarization impedance is 0.155 Ω·cm-2, at 850 °C, 1.6 V. It can be said that voltage-driven reduction is an effective and efficient method applied to interface engineering.