Decomposition of Methanol on Clean and Oxygen-Predosed V(100): A First-Principles Study

作者：Wang, Hui; He, Chao-zheng; Huai, Li-yuan; Tao, Fu-ming; Liu, Jing-yao^*

来源：Journal of Physical Chemistry C, 2012, 116(48): 25344-25353.

DOI：10.1021/jp307760a

• DENSITY-FUNCTIONAL THEORY
• ELASTIC BAND METHOD
• PARTIAL OXIDATION
• SURFACE
• ADSORPTION
• CATALYST
• FUEL
• SPECTROSCOPY
• METHOXY
• DEHYDROGENATION

The decomposition of CH3OH on clean and oxygen-predosed V(100) surfaces was studied on the basis of periodic density functional calculations and microkinetic modeling. The results indicate that the O-H bond scission of CH3OH is thermodynamically and kinetically favorable on clean V(100) while the C-H and C-O bond scissions are unlikely to occur at low temperature, and as a result, CH3O is the major intermediate in the decomposition process. The C-O bond scission of CH3O to form CH3 is much easier than the C-H bond scission to form HCHO. Hydrogenation of CH3 by the surface hydrogen from dissociating CH3OH and CH3O is responsible for the desorption of CH4 at low and high temperatures, respectively. HCHO further undergoes decomposition or/and coupling to form CO or/and C2H4. When oxygen is preadsorbed on the surface at low coverage, the O-H bond scission of CH3OH is virtually not affected, while the cleavages of the C-O and C-H bonds from CH3O are inhibited in different degrees, leading to the decrease in the ratio of CH4 produced at the low temperature relative to that at the high temperature. All products are delayed in temperature. The results are in good agreement with experimental observations.

• 出版日期2012-12-6
• 单位吉林大学