Smart Dual-Exsolved Self-Assembled Anode Enables Efficient and Robust Methane-Fueled Solid Oxide Fuel Cells

Abstract

Perovskite oxides have emerged as alternative anode materials for hydrocarbon-fueled solid oxide fuel cells (SOFCs). Nevertheless, the sluggish kinetics for hydrocarbon conversion hinder their commercial applications. Herein, a novel dual-exsolved self-assembled anode for CH4-fueled SOFCs is developed. The designed Ru@Ru-Sr2Fe1.5Mo0.5O6-δ(SFM)/Ru-Gd0.1Ce0.9O2-δ(GDC) anode exhibits a unique hierarchical structure of nano-heterointerfaces exsolved on submicron skeletons. As a result, the Ru@Ru-SFM/Ru-GDC anode-based single cell achieves high peak power densities of 1.03 and 0.63 W cm−2 at 800 °C under humidified H2 and CH4, surpassing most reported perovskite-based anodes. Moreover, this anode demonstrates negligible degradation over 200 h in humidified CH4, indicating high resistance to carbon deposition. Density functional theory calculations reveal that the created metal-oxide heterointerfaces of Ru@Ru-SFM and Ru@Ru-GDC have higher intrinsic activities for CH4 conversion compared to pristine SFM. These findings highlight a viable design of the dual-exsolved self-assembled anode for efficient and robust hydrocarbon-fueled SOFCs.