Synergistic In Situ Exsolved Ru Metal and Lattice‐Confined Single‐Atoms for High‐Performance Direct‐Methane Solid Oxide Fuel Cells

ABSTRACT Direct‐methane solid oxide fuel cells (DM‐SOFCs) hold significant promise as a high‐efficiency, low‐emission power‐generation technology capable of utilizing abundant methane via established natural gas infrastructure. Yet, poor methane catalysis and coking on conventional Ni‐based anodes limit performance. While steam addition in fuel promotes methane conversion and mitigates coking, the resulting methane‐steam reforming (MSR) and coke gasification reactions compete with electro‐oxidation for anodic active sites, limiting DM‐SOFCs performance enhancement. This trade‐off can be addressed by applying an anode catalyst layer (ACL) with high MSR activity. Here, we demonstrate a perovskite‐supported Ru dual‐site catalyst as an ACL, achieved by reducing SrTi 0.9 Ru 0.1 O 3‐δ , featuring both surface‐exsolved Ru nanoparticles and lattice‐confined Ru single atoms. Surface Ru nanoparticles preferentially activate CH 4 dehydrogenation, while atomic Ru, coupled with perovskite‐bulk oxygen vacancies, promote H 2 O dissociation. This synergy yields superior MSR activity relative to single nano metallic Ru site catalysts. As an DM‐SOFCs ACL, the catalyst enables a 1.34‐fold increase in power output (1.221 W cm −2 at 650°C) and robust durability (210 h at 600°C). This work provides the first atomic‐level evidence of synergistic catalysis between exsolved metal and lattice‐confined single atoms in exsolvable perovskite, establishing a new design paradigm for DM‐SOFC anode catalyst.