催化学报

催化学报 ›› 2013, Vol. 34 ›› Issue (5): 1002-1012.DOI: 10.1016/S1872-2067(12)60537-3

• 研究论文 • 上一篇    下一篇

Pd(111), Pd(100)及Pd(110)表面H2和O2直接合成H2O2的密度泛函理论研究

田鹏飞, 欧阳李科, 徐新潮, 徐晶, 韩一帆   

  1. 华东理工大学化学工程联合国家重点实验室, 上海 200237
  • 收稿日期:2012-12-30 修回日期:2013-05-20 出版日期:2013-05-06 发布日期:2013-05-06
  • 通讯作者: 韩一帆
  • 基金资助:

    国家自然科学基金(21176071,21106041).谨以此文纪念邓景发院士诞辰八十周年.

Density functional theory study of direct synthesis of H2O2 from H2 and O2 on Pd(111), Pd(100), and Pd(110) surfaces

TIAN Pengfei, OUYANG Like, XU Xinchao, XU Jing, HAN Yi-Fan   

  1. State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2012-12-30 Revised:2013-05-20 Online:2013-05-06 Published:2013-05-06
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21176071, 21106041).

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摘要：

采用周期性密度泛函理论研究了H2和O2在Pd(111),Pd(100)及Pd(110)表面上直接合成H2O2的反应机理,对反应的主要基元步骤进行了计算和分析.结果表明,Pd(111)表面对H2O2直接合成的催化选择性最好,表面原子密度较低的Pd(100)表面和Pd(110)表面上含有O-O键的表面物种解离严重,不利于H2O2的生成.H2O2的选择性与含有O-O键表面物种的O-O键能和表面物种的结合能有关.含有O-O键的表面物种在表面的结合能越大,越容易发生解离,不利于形成H2O2.

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关键词: 钯, 过氧化氢, 氢气, 氧气, 直接合成, 密度泛函理论

Abstract:

The direct synthesis of hydrogen peroxide (H2O2) from hydrogen (H2) and oxygen (O2) on Pd(111), Pd(100), and Pd(110) surfaces was investigated using periodic density functional theory (DFT) calculations. Several elementary steps making up this reaction were postulated and calculated. The Pd(111) surface shows the highest catalytic selectivity for H2O2 among the three surfaces. Open surfaces such as Pd(100) and Pd(110) are not favorable for this reaction because O-O-containing species on these surfaces dissociate easily. The O-O bond energy and the binding energy of O-O-containing surface species are responsible for catalytic selectivity. The higher binding energy of O-O-containing surface species is not favorable for the direct synthesis of H2O2 because the higher binding energy results in lower dissociation barriers.

Key words: Palladium, Hydrogen peroxide, Hydrogen, Oxygen, Direct synthesis, Density functional theory