posted on 2013-06-20, 00:00authored byLianming Zhao, Min Tan, Juan Chen, Qiuyue Ding, Xiaoqing Lu, Yuhua Chi, Guangwu Yang, Wenyue Guo, Qingtao Fu
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(Cβ–H) <
ΔE(Cα–H) ≈ ΔE(O–H). Loss of methyl and glycol occurs respectively
via O–H and Cβ–H activation, while
acetaldehyde elimination proceeds through two comparable O–H
and Cα–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 Cα–H activation but also
forms VO2(C2H4)+ via Cβ–H activation. The major product of ethylene
is formed via both O–H and Cβ–H activation
for yielding VO(OH)2+ and VO2(H2O)+. In the methanol reaction, both initial O–H
and Cα–H activation accounts for formaldehyde
and water elimination, but the former pathway is preferred.