Promoting oxygen evolution reaction by RuO2 nanoparticles in solid oxide CO2 electrolyzer

Electro-reduction of CO2 to CO via high-temperature solid oxide electrolysis cell (HT-SOEC) is an effective approach to reduce CO2 emissions and alleviate global warming effect. Significant efforts have been devoted to developing efficient electrode materials for accelerating the sluggish oxygen evolution reaction (OER) occurred at the SOEC anode. Herein, we report that RuO2 nanoparticles possess excellent OER activity at 800 degrees C and can notably promote the OER performance of strontium doped lanthanum manganite/yttria-stabilized zirconia (LSM/YSZ) anode in solid oxide CO2 electrolyzer. The current density is improved from 0.46 A cm(-2) to 0.74 A cm(-2) at 1.2 V and 800 degrees C after anchoring 6 wt.% RuO2 onto the surface of LSM/YSZ composite electrode, with the greatest enhancement of 60%. Characterizations of X-ray diffraction, X-ray photoelectron spectroscopy, temperature-programmed desorption of oxygen and transmission electron microscopy suggest that the combination of improved oxygen vacancies on the LSM/YSZ backbone and intrinsic OER activity of RuO2 nanoparticles greatly promote the OER performance in solid oxide CO2 electrolyzer.