title: Methane Activation Mediated by a Series of Cerium-Vanadium Bimetallic Oxide Cluster Cations: Tuning Reactivity by Doping.
abstract: The reactions of cerium-vanadium cluster cations Cex Vy Oz (+) with CH4 are investigated by time-of-flight mass spectrometry and density functional theory calculations. (CeO2 )m (V2 O5 )n (+) clusters (m=1,2, n=1-5; m=3, n=1-4) with dimensions up to nanosize can abstract one hydrogen atom from CH4 . The theoretical study indicates that there are two types of active species in (CeO2 )m (V2 O5 )n (+) , V[(Ot )2 ](.) and [(Ob )2 CeOt ](.) (Ot and Ob represent terminal and bridging oxygen atoms, respectively); the former is less reactive than the latter. The experimentally observed size-dependent reactivities can be rationalized by considering the different active species and mechanisms. Interestingly, the reactivity of the (CeO2 )m (V2 O5 )n (+) clusters falls between those of (CeO2 )2-4 (+) and (V2 O5 )1-5 (+) in terms of C-H bond activation, thus the nature of the active species and the cluster reactivity can be effectively tuned by doping.
authors.affiliation: The Institute for Chemical Physics, Key Laboratory of Cluster Science, School of Chemistry, Beijing Institute of Technology, 100081, Beijing, P.R. China. majiabi@bit.edu.cn.
authors.forename: Jia-Bi
authors.initials: JB
authors.lastname: Ma
authors.affiliation: State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, P.R. China.
authors.forename: Jing-Heng
authors.initials: JH
authors.lastname: Meng
authors.affiliation: State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, P.R. China. shengguihe@iccas.ac.cn.
authors.forename: Sheng-Gui
authors.initials: SG
authors.lastname: He
keywords: cluster compounds; density functional calculations; mass spectrometry; methane; radical ions