UV-Ozone Cleaning of Supported Poly(vinylpyrrolidone)-Stabilized Palladium Nanocubes: Effect of Stabilizer Removal on Morphology and Catalytic Behavior
UV-Ozone Cleaning of Supported Poly(vinylpyrrolidone)-Stabilized Palladium Nanocubes: Effect of Stabilizer Removal on Morphology and Catalytic Behavior
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DOI：
10.1021/la201007m
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发表时间：
2011-06-21
期刊：
影响因子：
3.9
通讯作者：
Kiwi-Minsker, Lioubov
中科院分区：
文献类型：
--
作者：
Crespo-Quesada, Micaela;Andanson, Jean-Michel;Kiwi-Minsker, Lioubov
合成了聚乙烯吡咯烷酮（PVP）稳定的Pd纳米立方体，沉积在碳基载体上，随后用UV-臭氧（UVO）处理，以消除仍然存在于表面上的痕量PVP。立方体，是一个物理上不利的形状，是非常容易重组，以尽量减少界面自由能，从而允许评估其形态稳定性在紫外线清洗。采用X射线光电子能谱（XPS）、X射线衍射（XRD）和原位衰减全反射红外光谱（ATR-IR）等技术对PVP的去除过程进行了监测。使用高分辨率扫描电子显微镜（SEM）成像来评估纳米立方体的形态。在乙炔的氢化中也研究了PVP去除的效果，显示出活性增加了4倍。这种方法可以应用于其他常见形状的纳米颗粒，暴露不同的晶面，以研究化学反应的结构敏感性。
Poly(vinylpyrrolidone) (PVP)-stabilized Pd nanocubes were synthesized, deposited on a carbon-based support, and subsequently treated with UV-ozone (UVO) in order to eliminate the traces of PVP still present on the surface. Cubes, being a thermodynamically unfavorable shape, are very prone to restructuring to minimize the interfacial free energy and thus allow the assessment of their morphological stability during UVO cleaning. The process of PVP removal was monitored by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and in situ attenuated total reflection infrared spectroscopy (ATR-IR). High-resolution scanning electron microscopy (SEM) imaging was used to evaluate the morphology of the nanocubes. The effect of PVP removal was also studied in the hydrogenation of acetylene, showing a 4-fold increase of activity. This method can be applied to nanoparticles of other common shapes, which expose different crystal planes, in order to study the structure sensitivity of chemical reactions.