Thermodynamically and Kinetically Stabilized Pt Clusters Against Sintering on CeO₂ Nanofibers Through Enclosing CeO₂ Nanocubes

Abstract Sintering is a major concern for the deactivation of supported metals catalysts, which is driven by the force of decreasing the total surface energy of the entire catalytic system. In this work, a double‐confinement strategy is demonstrated to stabilize 2.6 nm‐Pt clusters against sintering on electrospun CeO₂ nanofibers decorated by CeO₂ nanocubes (m‐CeO₂). Thermodynamically, with the aid of CeO₂‐nanocubes, the intrinsically irregular surface of polycrystalline CeO₂ nanofibers becomes smooth, offering adjacent Pt clusters with decreased chemical potential differences on a relatively uniform surface. Kinetically, the Pt clusters are physically restricted on each facet of CeO₂ nanocubes in a nanosized region. In situ high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) observation reveals that the Pt clusters can be stabilized up to 800 °C even in a high density, which is far beyond their Tammann temperature, without observable size growth or migration. Such a sinter‐resistant catalytic system is endowed with boosted catalytic activity toward both the hydrogenation of p‐nitrophenol after being aged at 500 °C and the sinter‐promoting exothermic oxidation reactions (e.g., soot oxidation) at high temperatures over 700 °C. This work offers new opportunities for exploring sinter‐resistant nanocatalysts, starting from the rational design of whole catalytic system in terms of thermodynamic and kinetic aspects.