Experimental and theoretical studies of the reaction between cationic vanadium oxide clusters and acetylene  

作　　者：YIN Shi MA YanPing DU Lin HE ShengGui GE MaoFa 

机构地区：[1]Beijing National Laboratory for Molecular Sciences (BNLMS), and State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China [2]Graduate University of the Chinese Academy of Sciences, Beijing 100039, China

出　　处：《Chinese Science Bulletin》2008年第24期3829-3838,共10页

基　　金：Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (Grant Nos.KJCX2-YW-N24,and KZCX2-YW-205);the Hundred Talents Funds,National Natural Science Foundation of China (Grant Nos.20577052,20673123 and 20703048);National Basic Research Program of China (Grant No.2006CB403701 and 2006CB932100)

摘　　要：The time of flight mass spectrometer coupled with a laser ablation/supersonic expansion cluster source and a fast flow reactor was adopted to study the reactivity of cationic vanadium oxide clusters(VmOn+) toward acetylene(C2H2) molecules under gas phase(P,～ 1.14 kPa),under near room temperature(T,～ 350 K) conditions.Association products,VmOnC2H2+(m,n = 2,4;2,6;3,7―8;4,9―11;5,12―13;6,13―16,and 7,17),are observed.The oxidation of C2H2 by(V2O5)+n(n = 1―3) is experimentally identified.The reactivity of(V2O5)+ n decreases as n increases.Density functional theory(DFT) calculations were carried out to interpret the reaction mechanisms.The DFT results indicate that a terminal oxygen atom from V2O5+ can transfer overall barrierlessly to C2H2 at room temperature,which is in agreement with the experimental observation.Other experimental results such as the observation of V2O6C2H+2 and non-observation of V2O7,8C2H+2 in the experiments are also well interpreted based on the DFT calculations.The reactivity of vanadium oxide clusters toward acetylene and other hydrocarbons may be considered in identifying molecular level mechanisms for related heterogeneous catalysis.The time of flight mass spectrometer coupled with a laser ablation/supersonic expansion cluster source and a fast flow reactor was adopted to study the reactivity of cationic vanadium oxide clusters （VinOS,） toward acetylene （C2H2） molecules under gas phase （P, - 1.14 kPa）, under near room temperature （T, - 350 K） conditions. Association products, VmOnC2H2^＋ （m,n = 2,4; 2,6; 3,7-8; 4,9-11; 5,12-13; 6,13-16, and 7,17）, are observed. The oxidation of C2H2 by （V2Os）n^＋ （n = 1 -3） is experimentally identified. The reactivity of （V2O5）n^＋ decreases as n increases. Density functional theory （DFT） calculations were carried out to interpret the reaction mechanisms. The DFT results indicate that a terminal oxygen atom from V2O5^＋ can transfer overall barrierlessly to C2H2 at room temperature, which is in agreement with the experimental observation. Other experimental results such as the observation of V206C2H2^＋ and nonobservation of V2O7,8C2H2^＋ in the experiments are also well interpreted based on the DFT calculations. The reactivity of vanadium oxide clusters toward acetylene and other hydrocarbons may be considered in identifying molecular level mechanisms for related heterogeneous catalysis.

关 键 词：钒 氧化物 速流电抗器 DFT 

分 类 号：O64[理学—物理化学]