In situ exsolved CoFe alloy nanoparticles for stable anodic methane reforming in solid oxide electrolysis cells

Replacing the sluggish oxygen evolution reaction with a favorable methane (CH4) reforming reaction at the anode of solid oxide electrolysis cells (SOECs) can greatly reduce the electrical demand for CO2 electroreduction at the cathode. However, the perovskite anode always displays limited activity and stability for CH4 reforming. Herein, through fine-tuning of the average exsolution energy of the B-site components, high-density CoFe alloy nanoparticles are exsolved on the surface of La0.6Sr0.4Ti0.3Fe0.5Co0.2O3-δ (LSTFC2) anode after reduction, which shows superior anodic CH4 reforming performance, with a CH4 conversion of 86.9% and CO selectivity of 90.1% at 800°C. Moreover, stable operation over 1,250 h with a CO selectivity above 95% is achieved. The electrical energy consumption for CO production decreases from 3.46 kWh m−3 for conventional SOECs to 0.31 kWh m−3 for CH4-assisted SOECs. This work provides an efficient strategy to thermodynamically boost the cathodic CO2 electroreduction performance and simultaneously convert CH4 to syngas at the anode.