Periodic density functional theory study of propane oxidative dehydrogenation over V2O5(001) surface
Periodic density functional theory study of propane oxidative dehydrogenation over V2O5(001) surface
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V2O5(001)表面丙烷氧化脱氢的周期密度泛函理论研究
DOI：
10.1021/ja0611745
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发表时间：
2006-08-30
影响因子：
15
通讯作者：
Fan, Kang-Nian
中科院分区：
文献类型：
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作者：
Fu, Hui;Liu, Zhi-Pan;Fan, Kang-Nian
采用周期密度泛函理论（DFT）方法研究了丙烷在V2 O 5（001）单晶上的氧化脱氢反应。确定了丙烷转化为丙烯的能量学和途径。结果表明：（1）丙烷的C-H键可以被表面的端基氧原子和桥连氧原子激活，激活能相近;在末端O位点，自由基和氧代插入途径都可能用于C-H键活化，而在桥接O位点只有氧代插入机制是可行的。(ii)与末端O位相比，桥O位的丙氧基更容易生成丙烯，这是因为桥O位的丙氧基结合较弱。结果表明，单晶V_2O_5（001）不是一种好的催化剂，因为其末端O太活泼，不能释放丙烯。预期用于ODH反应的有效催化剂必须在活化C-H键的能力和释放丙烯的能力之间做出折衷。
The oxidative dehydrogenation (ODH) of propane on single-crystal V2O5( 001) is studied by periodic density functional theory (DFT) calculations. The energetics and pathways for the propane to propene conversion are determined. We show that (i) the C-H bond of propane can be activated by both the terminal and the bridging lattice O atoms on the surface with similar activation energies. At the terminal O site both the radical and the oxo-insertion pathways are likely for the C-H bond activation, while only the oxoinsertion mechanism is feasible at the bridging O site. (ii) Compared to that at the terminal O site, the propene production from the propoxide at the bridging O site is much easier due to the weaker binding of propoxide at the bridging O. It is concluded that single-crystal V2O5( 001) is not a good catalyst due to the terminal O being too active to release propene. It is expected that an efficient catalyst for the ODH reaction has to make a compromise between the ability to activate the C-H bond and the ability to release propene.