Noncrystalline-to-Crystalline Transformations in Pt Nanoparticles
Noncrystalline-to-Crystalline Transformations in Pt Nanoparticles
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DOI：
10.1021/ja405497p
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发表时间：
2013-09-04
影响因子：
15
通讯作者：
Yang, Judith C.
中科院分区：
文献类型：
--
作者：
Li, Long;Wang, Lin-Lin;Yang, Judith C.
我们表明，非晶到结晶过渡的支持Pt纳米粒子（NPs）在亚纳米到纳米尺寸范围内的统计性质，并强烈影响颗粒大小，支持，和吸附物（在这里，我们使用H-2）。与体相不同，非晶相存在于小纳米颗粒中并且在小纳米颗粒中是稳定的，反映了一般介观特征。通过高分辨率透射电子显微镜对>3000个颗粒的观察显示了非晶态到晶态的非突变过渡区;存在无序和有序NP共存的尺寸区域。发生这种转变的NP大小强烈依赖于吸附物和支持，这种效果是一般的后期5D过渡金属。所有结果通过颗粒-载体-吸附物相互作用的统计描述进行协调。
We show that the noncrystalline-to-crystalline transition of supported Pt nanoparticles (NPs) in the subnanometer to nanometer size range is statistical in nature, and strongly affected by particle size, support, and adsorbates (here we use H-2). Unlike in the bulk, a noncrystalline phase exists and is stable in small NPs, reflecting a general mesoscopic feature. Observations of >3000 particles by high-resolution transmission electron microscopy show a noncrystalline-to-crystalline transition zone that is nonabrupt; there is a size regime where disordered and ordered NPs coexist. The NP size at which this transition occurs is strongly dependent on both the adsorbate and the support, and this effect is general for late 5d transition metals. All results are reconciled via a statistical description of particle-support-adsorbate interactions.