甲醇在M@CNTs表面吸附和初步裂解机理的DFT研究

基于密度泛函理论(DFT)研究了CH_3OH在M@CNTs(M=Fe、Co、Ni、Cu、Fe_2、Co_2、FeCo)表面吸附和初步裂解机理.在M@CNTs表面CH_3OH裂解存在C-H、C-O、O-H 3条可能路径.我们计算了CH_3OH及中间体在CNTs和M@CNTs表面的吸附能,并计算了3条可能路径下的相关反应热和活化能.计算结果表明,CH_3OH在CNTs和M@CNTs表面是物理吸附,O-H键断裂是最有利的路径,其在不同催化剂表面的活化能顺序是CNTs(1.60 eV)、Cu@CNTs(1.57 eV)、Ni@CNTs(1.38 eV)、Co@CNTs(1.11 eV)、Fe@CNTs(1.10 eV)、Fe_2@CNTs(1.06 eV)、Co_2@CNTs(1.00 eV)、Fe Co@CNTs(0.76 eV),即Fe Co@CNTs可作为CH_3OH初步裂解的有效催化剂.

The Study of the Mechanism of Methanol Cracking on the M@CNTs by DFT

Density functional theory (DFT) is used to study the adsorption and initial cracking mechanism of CH3OH on the surface of M@CNTs (M= Fe, Co, Ni, Cu, Fe2, Co2, FeCo). There are three possible paths of CH3OH cracking on the surface of M@CNTs: C-H, C-O and O-H. In this paper, the adsorption energy of CH3OH and intermediates on CNTs surface and M@CNTs surface were calculated, and the relevant reaction energy and activation energy under three possible paths were calculated. The calculation results show that CH3OH is physically adsorbed on the surface of CNTs and M@CNTs, and O-H bond cleavage is the most favorable path. The order of activation energy on different catalyst surfaces is CNTs (1.60eV), Cu@CNTs (1.57eV), Ni@CNTs(1.38eV), Co@CNTs(1.11eV), Fe@CNTs(1.10eV), Fe2@CNTs(1.06eV), Co2@CNTs(1.00eV), FeCo@CNTs(0.76eV), namely FeCo@CNTs can be used as an effective catalyst for the initial cracking of CH3OH.