Lu Liu1, Chenghang Zheng2, Junfeng Wang1, Yongxin Zhang2, Xiang Gao 2, Kefa Cen2


School of Energy and Power Engineering, Jiangsu University, Zhenjiang 212013, China
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China



Received: December 26, 2017
Revised: February 27, 2018
Accepted: February 27, 2018
Download Citation: ||https://doi.org/10.4209/aaqr.2017.12.0597  


Cite this article:
Liu, L., Zheng, C., Wang, J., Zhang, Y., Gao, X. and Cen, K. (2018). NO Adsorption and Oxidation on Mn Doped CeO2 (111) Surfaces: A DFT+U Study. Aerosol Air Qual. Res. 18: 1080-1088. https://doi.org/10.4209/aaqr.2017.12.0597


HIGHLIGHTS

  • A DFT+U study of NO adsorption and oxidation on Mn-doped CeO2 surfaces.
  • Report the effect of the high mobility of O anions near Mn anion in oxidation.
  • NO preferentially interacts with O first neighbor of Mn and NO2* is formed.
  • ONOO* species are formed when NO and O2 co-adsorbe on defective surface.
  • Electron transfer occurs from the slab to NO when oxidation of NO is involved.

ABSTRACT


The adsorption of NO molecules on Mn-doped CeO2 (111) surfaces for NO oxidation has been studied by employing the periodic density functional theory plus U (DFT+U) method. Through our calculations, it is demonstrated how Mn-doped CeO2 with superior NO oxidation activity benefits from the high mobility of the oxygen near the Mn cations. On unreduced Mn-doped CeO2 (111) surfaces, the NO molecule preferentially interacted with the first neighboring O of the Mn cation, with the N also bonding to an Mn cation (Eads = –3.30 eV) or Ce cation (Eads = –2.90 eV). When NO adsorbs on the surface of defective Mn-doped CeO2 with O2 adsorbed in advance, an ONOO* four atoms species is formed on the surface (Eads = –2.51 eV and –2.02 eV), which is an intermediate and can decompose into NO2, NO2* and O*. The adsorption structure with higher adsorption energy has a closer geometry to NO2, indicating a deeper oxidation of NO. The calculation results indicate that the presence of Mn only has a strong effect on the nearby oxygen atoms and that the Mn-doped CeO2 surface has similar properties to a noble metal in NO oxidation catalysis. In DOS plots, the spin of the electron state of the adsorption structures involving the oxidation of NO is symmetric, indicating that electron transfer occurs from the slab to NO and strong covalent bonds are formed between N and O on the slab, which can also be confirmed by the charge density difference plots.


Keywords: Adsorption; Ceria; Manganese; NO; Density functional theory.

 



Don't forget to share this article 

 

Subscribe to our Newsletter 

Aerosol and Air Quality Research has published over 2,000 peer-reviewed articles. Enter your email address to receive latest updates and research articles to your inbox every second week.

Latest coronavirus research from Aerosol and Air Quality Research

2018 Impact Factor: 2.735

5-Year Impact Factor: 2.827


SCImago Journal & Country Rank

Aerosol and Air Quality Research (AAQR) is an independently-run non-profit journal, promotes submissions of high-quality research, and strives to be one of the leading aerosol and air quality open-access journals in the world.