Understanding the catalytic activity of nanoporous gold: Role of twinning in fcc lattice.
Understanding the catalytic activity of nanoporous gold: Role of twinning in fcc lattice.
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DOI：
10.1063/1.4994701
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发表时间：
2017-07
期刊：
影响因子：
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通讯作者：
M. Krajčí;S. Kameoka;A. Tsai
中科院分区：
文献类型：
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作者：
M. Krajčí;S. Kameoka;A. Tsai
通过Al2Au脱合金制备的纳米多孔金（NPG）表现出对CO氧化的高催化活性与NPG的面心立方晶格中的孪晶缺陷密度之间的相关性。还发现在NPG的内表面上，非常常见的孪晶缺陷可以产生紧密堆积的六配位催化活性Au原子行，表示为W链。在这项工作中，使用密度泛函理论的方法，我们调查的能量条件，形成，热稳定性，和这些活性位点的化学反应。分子氧化学吸附在各种表面网站的可能性进行了详细研究。色散相互作用的贡献也被认为是。NPG中活性六配位原子的计算表面密度与负载型金纳米颗粒催化剂的表面密度、分子氧的放热化学吸附以及CO氧化反应途径的能量分布表明，通过孪生产生的六配位位点可以显著地促进NPG的催化活性。
Nanoporous gold (NPG) prepared by de-alloying Al2Au exhibits correlation between the high catalytic reactivity towards CO oxidation and the density of twinning defects in the fcc lattice of NPG. It was also discovered that on the internal surface of NPG, quite common twinning defects can create close-packed rows of six-coordinated catalytically active Au atoms denoted as W-chains. In this work, using density functional theory methods, we investigate energy conditions for formation, thermal stability, and chemical reactivity of these active sites. The possibility of dioxygen chemisorption on various surface sites is studied in detail. A contribution from the dispersion interactions is also considered. The calculated surface density of the active six-coordinated atoms in NPG comparable with that of supported gold nanoparticle catalysts, exothermic chemisorption of dioxygen, and the energy profiles of reaction pathways for CO oxidation indicate that the six-coordinated sites created by twinning can significantly contribute to the catalytic activity of NPG.