High reactivity of nanosized niobium oxide cluster cations in methane activation: A comparison with vanadium oxides

Journal Article · Mon Sep 28 00:00:00 EDT 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4931972· OSTI ID:22489646

Ding, Xun-Lei; Wang, Dan ^[1]; Wu, Xiao-Nan; Li, Zi-Yu; Zhao, Yan-Xia; He, Sheng-Gui ^[2]

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1. Department of Mathematics and Physics, North China Electric Power University, Beinong Road 2, Huilongguan, Beijing 102206 (China)
2. Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

The reactions between methane and niobium oxide cluster cations were studied and compared to those employing vanadium oxides. Hydrogen atom abstraction (HAA) reactions were identified over stoichiometric (Nb{sub 2}O{sub 5}){sub N}{sup +} clusters for N as large as 14 with a time-of-flight mass spectrometer. The reactivity of (Nb{sub 2}O{sub 5}){sub N}{sup +} clusters decreases as the N increases, and it is higher than that of (V {sub 2}O{sub 5}){sub N}{sup +} for N ≥ 4. Theoretical studies were conducted on (Nb{sub 2}O{sub 5}){sub N}{sup +} (N = 2–6) by density functional calculations. HAA reactions on these clusters are all favorable thermodynamically and kinetically. The difference of the reactivity with respect to the cluster size and metal type (Nb vs V) was attributed to thermodynamics, kinetics, the electron capture ability, and the distribution of the unpaired spin density. Nanosized Nb oxide clusters show higher HAA reactivity than V oxides, indicating that niobia may serve as promising catalysts for practical methane conversion.

• OSTI ID: 22489646
• Journal Information: Journal of Chemical Physics, Vol. 143, Issue 12; Other Information: (c) 2015 AIP Publishing LLC; 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
77 NANOSCIENCE AND NANOTECHNOLOGY
ATOMS
CATALYSTS
CATIONS
COMPARATIVE EVALUATIONS
DENSITY
DENSITY FUNCTIONAL METHOD
ELECTRON CAPTURE
HYDROGEN
KINETICS
METALS
METHANE
NANOSTRUCTURES
NIOBATES
NIOBIUM OXIDES
REACTIVITY
SPIN
THERMODYNAMICS
TIME-OF-FLIGHT MASS SPECTROMETERS
VANADIUM OXIDES