Entropy‐Controlled Exsolution of Highly Dispersed Nickel‐Based Active Metals From Spinel Oxide via Optimizing Metal‐Support Interaction for Dry Reforming of Methane

ABSTRACT Sintering and coking are critical barriers to achieving high performance in dry reforming of methane (DRM) catalysts. A finely dispersed and thermostable Ni‐based catalyst is the key to address these issues. By leveraging the intrinsic superiorities of high‐entropy oxides in high‐temperature stability and low atomic diffusivity, in this study, a highly dispersed Ni‐based catalyst is synthesized via an entropy‐controlled exsolution of active components. By increasing the number of transition‐metal elements in spinel oxides, the active metal‐support interaction (MSI) can be continuously strengthened, which controls the exsolution and thermal stability of Ni‐based active metal in harsh reaction conditions of DRM. An optimized medium‐entropy spinel (Mg _0.4 Ni _0.2 Co _0.2 Zn _0.2 )Al ₂ O ₄ with the exsolution of finely dispersed Ni–Co nanoparticles displayed superior activity and stability in thermal DRM at 800°C and photothermal DRM. This entropy‐controlled MSI and exsolution principle provides a significant strategy for designing robust catalysts resistant to sintering and coking for high‐temperature reactions like DRM in thermal and photothermal systems.