Non-precious metal-based catalysts for the acidic oxygen evolution reaction (OER) offer great potential due to their continuously improving performance, earth abundance and low cost. However, their catalytic activity and stability remain inadequate for practical applications. Here we implement an interfacial modulation strategy by coating cobalt oxide (e.g., Co₃O₄) nanocrystals with a single-metal-atom–modified, nitrogen-doped carbon (MNC) layer, and further optimize the interface between Co₃O₄ and MCN through single atom metal regulation. Across the series, Co₃O₄/MnNC exhibits a trend-like optimum, delivering overpotentials of 296 and 401 mV at 10 and 100 mA·cm^–2, respectively, and showing excellent durability with only a 36 mV increase after 240 h at 10 mA·cm^–2. Combining X-ray absorption fine structure (XAFS) characterization and density functional theory (DFT) calculations, the Co–N–Mn structure is identified as the active site, while the coating layer suppresses surface structural relaxation of Co₃O₄, thereby improving the structural stability. Moreover, in situ XAFS investigations confirm the formation of a stable Co–N–Mn interfacial structure under operational conditions. These results offer interfacial modulation as an effective route for high-performance, earth-abundant OER catalysts in acidic media.

Bimetallic catalysts are extensively utilized in heterogeneous catalysis due to their superior performance. The catalytic efficiency of these catalysts is influenced by various factors, particularly their structure and active sites, which are often overlooked in terms of mechanism and evolution. Herein, we present AuCuO/Al₂O₃, which feature active CuO island structures on its surface, demonstrating exceptional catalytic oxidative dehydrogenation performance with isopropanol. Compared with untreated AuCu/Al₂O₃, AuCuO/Al₂O₃ shows significantly enhanced activity, with nearly an order of magnitude improvement in catalytic performance at low temperatures. This enhancement is attributed to the element segregation process and the positive effect of Cu structures on catalytic activity. Theoretical simulations reveal that Cu and Au elements migrate in opposite directions, leading to the formation of CuO islands. In-situ transmission electron microscopy (TEM) images under oxidizing and thermal conditions elucidated the evolution of these structures. This work uncovers the evolution mechanism of active structures and interfaces in bimetallic catalysts, offering insights into the construction of interfacial sites and optimization of catalyst structures for high-performance applications.