高等学校化学学报 ›› 2017, Vol. 38 ›› Issue (9): 1611-1618.doi: 10.7503/cjcu20170189

• 物理化学 • 上一篇    下一篇

Ru修饰前后Pd(111)面的性质及对糠醛吸附的比较研究

钱梦丹, 罗伟, 倪哲明(), 夏盛杰, 薛继龙, 蒋军辉   

  1. 浙江工业大学化学工程学院, 杭州310014
  • 收稿日期:2017-03-29 出版日期:2017-09-10 发布日期:2017-08-25
  • 作者简介:联系人简介: 倪哲明, 女, 博士, 教授, 博士生导师, 主要从事计算化学及纳米无机光催化材料研究. E-mail: jchx@zjut.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 21503188)和浙江省大学生科技创新活动计划(新苗人才计划)项目资助

Comparative Study on the Properties and Adsorption of Furfural of Pd(111) Surface Before and After Ru Modification

QIAN Mengdan, LUO Wei, NI Zheming*(), XIA Shengjie, XUE Jilong, JIANG Junhui   

  1. College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
  • Received:2017-03-29 Online:2017-09-10 Published:2017-08-25
  • Contact: NI Zheming E-mail:jchx@zjut.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No;21503188) and the College Students Technology Innovation Plan of Zhejiang Province(Xin Miao Talent Plan), China

摘要:

采用密度泛函理论研究了Pd(111)面和Ru-Pd(111)面的性质及对糠醛的吸附. 原子尺寸因素、 相对键长、 形成能及d带中心等计算结果表明, Ru-Pd(111)面比Pd(111)面稳定且活性强, Ru的修饰优化了Pd(111)面的几何构型. 糠醛在Pd(111)面及Ru-Pd(111)面的初始吸附位分别为P(top-bridge)位及P(Pd-fcc-Ru-fcc)位时, 吸附能最大, 吸附构型最稳定. 由电荷布局和差分电荷密度可得, 糠醛在 Ru-Pd(111)面上电荷转移数更多, 相互作用更强烈, 因此吸附能更大. 分析态密度可知, 产生吸附的主要原因是位于-7.34 eV处至费米能级处的p, d轨道杂化. 吸附于Ru-Pd(111)面后糠醛分子的p轨道向低能级偏移程度更明显, 使Ru改性后的Pd催化剂具有更好的催化活性.

关键词: 密度泛函理论, 糠醛, Pd(111)面, Ru-Pd(111)面, 吸附

Abstract:

The properties of Pd(111), Ru-Pd(111) surfaces and their adsorption of furfural were investigated via periodic density functional theory(DFT) calculations. The results of atomic size factor, relative bond length, formation energy and d-band center showed that Ru-Pd(111) surface was more stable and active than Pd(111), Ru modification could improve the geometric configuration. For the adsorption of furfural on Pd(111) and Ru-Pd(111) surfaces, the results showed that when the initial adsorption at P(top-bridge) or P(Pd-fcc-Ru-fcc) site, the adsorption energy was the highest and the adsorption configuration was the most stable. After analyzing Mulliken atomic charge population and the deformation density, it was found that for the adsorption of furfural on Ru-Pd(111) surface, the number of charge transferred was more and the interaction was stronger, therefore it’s adsorption energy was higher. The result of state density indicated that the main reason for the adsorption was that the p and d orbitals hybridization existed at -7.34 eV relative to Fermi level. Meanwhile, the p-orbital of furfural shifted to the low-level was more obvious on Ru-Pd(111) surface, so Pd catalyst after Ru modification had better catalytic activity.

Key words: Density functional theory, Furfural, Pd(111) surface, Ru-Pd(111) surface, Adsorption