烧结
材料科学
催化作用
纳米材料基催化剂
放热反应
化学工程
微晶
纳米纤维
扫描透射电子显微镜
纳米技术
纳米颗粒
透射电子显微镜
复合材料
冶金
化学
生物化学
有机化学
工程类
作者
Jun Wang,Suting Liu,Mingyu Tang,Wanlin Fu,Yunpeng Wang,Kuibo Yin,Yunqian Dai
出处
期刊:Small
[Wiley]
日期:2023-04-24
卷期号:19 (34)
被引量:3
标识
DOI:10.1002/smll.202300547
摘要
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.
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