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 (CH 4 ) reforming reaction at the anode of solid oxide electrolysis cells (SOECs) can greatly reduce the electrical demand for CO 2 electroreduction at the cathode. However, the perovskite anode always displays limited activity and stability for CH 4 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 La 0.6 Sr 0.4 Ti 0.3 Fe 0.5 Co 0.2 O 3-δ (LSTFC2) anode after reduction, which shows superior anodic CH 4 reforming performance, with a CH 4 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 CH 4 -assisted SOECs. This work provides an efficient strategy to thermodynamically boost the cathodic CO 2 electroreduction performance and simultaneously convert CH 4 to syngas at the anode.