Exsolved Alloy‐Perovskite Heterostructure Enables Efficient and Robust CH 4 ‐CO 2 Solid Oxide Fuel Cells

ABSTRACT Carbon deposition on conventional Ni‐based cermet anodes remains a critical challenge, severely compromising the efficiency and durability of solid oxide fuel cells (SOFCs) operating via dry reforming of methane (DRM). Herein, we report a novel RhFe (RF) alloy‐decorated perovskite anode, synthesized through in situ exsolution from Sr 1.9 Fe 1.5‐x Mo 0.5 Rh x O 6−δ (x = 0.1, 0.2, and 0.3, denoted as SFMR10, SFMR20, and SFMR30, respectively). This architecture combines the high DRM activity of the alloy‐perovskite heterointerface with the structural stability conferred by the embedded heterostructure. At 800°C, with a CH 4 ‐CO 2 (1:1) feed, the optimized RF@SFMR20 anode‐based single cell achieves a peak power density of 0.86 W cm −2 and maintains stable output for over 200 h, rivaling most previously reported anodes for DRM‐SOFCs. Combined experimental and theoretical analyses reveal that the RF alloy‐SFMR perovskite heterostructure, featuring a strong metal‐support interaction, exhibits a lower energy barrier for DRM compared to pristine Sr 2 Fe 1.5 Mo 0.5 O 6 (SFM). These findings demonstrate a strongly coupled alloy‐perovskite heterostructure as a promising strategy for enabling sustainable operation of DRM‐SOFCs.