College of Science, China University of Petroleum , Qingdao, Shandong 266580, P.R. China.
J Phys Chem A. 2013 Jun 20;117(24):5161-70. doi: 10.1021/jp4021454. Epub 2013 Jun 5.
The activation of ethanol and methanol by VO2(+) in gas phase has been theoretically investigated by using density functional theory (DFT). For the VO2(+)/ethanol system, the activation energy (ΔE) is found to follow the order of ΔE(C(β)-H) < ΔE(C(α)-H) ≈ ΔE(O-H). Loss of methyl and glycol occurs respectively via O-H and C(β)-H activation, while acetaldehyde elimination proceeds through two comparable O-H and C(α)-H activations yielding both VO(H2O)(+) and V(OH)2(+). Loss of water not only gives rise to VO(CH3CHO)(+) via both O-H and C(α)-H activation but also forms VO2(C2H4)(+) via C(β)-H activation. The major product of ethylene is formed via both O-H and C(β)-H activation for yielding VO(OH)2(+) and VO2(H2O)(+). In the methanol reaction, both initial O-H and C(α)-H activation accounts for formaldehyde and water elimination, but the former pathway is preferred.
采用密度泛函理论（DFT）对气相中 VO2(+) 对乙醇和甲醇的活化进行了理论研究。对于 VO2(+)/乙醇体系，发现活化能（ΔE）的顺序为 ΔE(C(β)-H) < ΔE(C(α)-H) ≈ ΔE(O-H)。甲基和乙二醇分别通过 O-H 和 C(β)-H 活化而失去，而乙醛的消除则通过两个相当的 O-H 和 C(α)-H 活化进行，生成 VO(H2O)(+) 和 V(OH)2(+)。失去水不仅通过 O-H 和 C(α)-H 活化导致 VO(CH3CHO)(+)的形成，而且还通过 C(β)-H 活化形成 VO2(C2H4)(+)。乙烯的主要产物是通过 O-H 和 C(β)-H 活化形成的，生成 VO(OH)2(+) 和 VO2(H2O)(+)。在甲醇反应中，初始的 O-H 和 C(α)-H 活化都导致甲醛和水的消除，但前者途径更占优势。
