Tuning the charge states of CrW{sub 2}O{sub 9} clusters deposited on perfect and defective MgO(001) surfaces with different color centers: A comprehensive DFT study

Journal Article · Sat May 07 00:00:00 EDT 2016 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4947549· OSTI ID:22657966

Zhu, Jia; Zhang, Hui; Tong, Yawen; Wang, Chengxing ^[1]; Wang, Bin; Huang, Xin ^[2]; Zhang, Yongfan ^[2]

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1. College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022 (China)
2. College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108 (China)

The structures and electronic properties of bimetallic oxide CrW{sub 2}O{sub 9} clusters supported on the perfect and defective MgO(001) surfaces with three different color centers, F{sub S}{sup 0}, F{sub S}{sup +}, and F{sub S}{sup 2+} centers, respectively, have been investigated by density functional theory calculations. Our results show that the configurations, adsorption energies, charge transfers, and bonding modes of dispersed CrW{sub 2}O{sub 9} clusters are sensitive to the charge states of the F{sub S} centers. Compared with the gas-phase configuration, the CrW{sub 2}O{sub 9} clusters supported on the defective surfaces are distorted dramatically, which exhibit different chain structures. On the perfect MgO surface, the depositions of clusters do not involve obvious charge transfer, while the situation is quite different on the defective MgO(001) surfaces in which significant electron transfer occurs from the surface to the cluster. Interestingly, this effect becomes more remarkable for electron-rich oxygen vacancies (F{sub S}{sup 0} center) than that for electron-poor oxygen vacancies (F{sub S}{sup +} and F{sub S}{sup 2+} centers). Furthermore, our work reveals a progressive Brønsted acid sites where spin density preferentially localized around the Cr atoms not the W atoms for all kinds of F{sub S}-centers, indicating the better catalytic activities can be expected for CrW{sub 2}O{sub 9} cluster on defective MgO(001) surfaces with respect to the W{sub 3}O{sub 9} cluster.

• OSTI ID: 22657966
• Journal Information: Journal of Chemical Physics, Vol. 144, Issue 17; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CHARGE STATES
COLOR CENTERS
DENSITY FUNCTIONAL METHOD
DEPOSITION
DEPOSITS
ELECTRON TRANSFER
EXPERIMENTAL DATA
MAGNESIUM OXIDES
SURFACES