Chen Lin, Janssens Ton V W, Grönbeck Henrik
Department of Physics and Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
Umicore Denmark ApS, Nøjsomhedsvej 20, DK-2800 Kgs. Lyngby, Denmark.
Phys Chem Chem Phys. 2019 Jun 7;21(21):10923-10930. doi: 10.1039/c9cp01576k. Epub 2019 May 15.
A general challenge in density functional theory calculations is to simultaneously account for different types of bonds. One such example is reactions in zeolites where both van der Waals and chemical bonds should be described accurately. Here, we use different exchange-correlation functionals to explore O dissociation over pairs of Cu(NH) complexes in Cu-Chabazite. This is an important part of selective catalytic reduction of NO using NH as a reducing agent. The investigated functionals are PBE, PBE+U, PBE+D, PBE+U+D, PBE-cx, BEEF and HSE06+D. We find that the potential energy landscape for O activation and dissociation depends critically on the choice of functional. However, the van der Waals contributions are similarly described by the functionals accounting for this interaction. The discrepancies in the potential energy surface are instead related to different descriptions of the Cu-O chemical bond. By investigating the electronic, structural and energetic properties of reference systems including bulk copper oxides and (CuO) enzymatic crystals, we find that the PBE+U approach together with van der Waals corrections provides a reasonable simultaneous accuracy of the different bonds in the systems.
密度泛函理论计算中的一个普遍挑战是要同时考虑不同类型的键。一个这样的例子是沸石中的反应，其中范德华力和化学键都需要被准确描述。在这里，我们使用不同的交换关联泛函来研究铜离子交换菱沸石中铜（氨）络合物对之间的氧解离。这是以氨作为还原剂选择性催化还原一氧化氮的一个重要部分。所研究的泛函有PBE、PBE+U、PBE+D、PBE+U+D、PBE-cx、BEEF和HSE06+D。我们发现氧活化和解离的势能面严重依赖于泛函的选择。然而，考虑这种相互作用的泛函对范德华力贡献的描述相似。势能面的差异反而与铜 - 氧化学键的不同描述有关。通过研究包括块状氧化铜和（氧化铜）酶晶体在内的参考体系的电子、结构和能量性质，我们发现PBE+U方法与范德华力校正一起能合理地同时准确描述体系中不同的键。
