Promoting exsolution of RuFe alloy nanoparticles on SrFeRuMoO via repeated redox manipulations for CO electrolysis.

Metal nanoparticles anchored on perovskite through in situ exsolution under reducing atmosphere provide catalytically active metal/oxide interfaces for CO electrolysis in solid oxide electrolysis cell. However, there are critical challenges to obtain abundant metal/oxide interfaces due to the sluggish diffusion process of dopant cations inside the bulk perovskite. Herein, we propose a strategy to promote exsolution of RuFe alloy nanoparticles on SrFeRuMoO perovskite by enriching the active Ru underneath the perovskite surface via repeated redox manipulations. In situ scanning transmission electron microscopy demonstrates the dynamic structure evolution of SrFeRuMoO perovskite under reducing and oxidizing atmosphere, as well as the facilitated CO adsorption at RuFe@SrFeRuMoO interfaces. Solid oxide electrolysis cell with RuFe@SrFeRuMoO interfaces shows over 74.6% enhancement in current density of CO electrolysis compared to that with SrFeRuMoO counterpart as well as impressive stability for 1000 h at 1.2 V and 800 °C.