College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, People's Republic of China.
J Chem Phys. 2010 Jan 28;132(4):044111. doi: 10.1063/1.3292028.
The C-N bond breaking of methylamine on clean, carbon (nitrogen, oxygen)-modified Mo(100) [denoted as Mo(100) and Mo(100)-C(N,O), respectively], Mo(2)C(100), MoN(100), and Pt(100) surfaces has been investigated by the first-principles density functional theory (DFT) calculations. The results show that the reaction barriers of the C-N bond breaking in CH(3)NH(2) on Mo(100)-C(N,O) are higher than that on clean Mo(100). The calculated energy barrier can be correlated linearly with the density of Mo 4d states at the Fermi level after the adsorption of CH(3)NH(2) for those surfaces. Moreover, the DFT results show that the subsurface atom, e.g., carbon, can reduce the reaction barrier. In addition, We noticed that the activation energies for the C-N bond breaking on Mo(2)C(100) and MoN(100) are similar to that on Pt(100), suggesting that the catalytic properties of the transition metal carbides and nitrides for C-N bond scission of CH(3)NH(2) might be very similar to the expensive Pt-group metals.
采用第一性原理密度泛函理论（DFT）计算研究了在清洁的 Mo(100)[分别表示为 Mo(100)和 Mo(100)-C(N,O)]、Mo(2)C(100)、MoN(100)和 Pt(100)表面上，甲胺中 C-N 键在氮气、氧改性碳上的断裂反应。结果表明，在 Mo(100)-C(N,O)上 CH(3)NH(2)中 C-N 键断裂的反应势垒高于清洁 Mo(100)上的反应势垒。对于这些表面，在吸附 CH(3)NH(2)后，与费米能级处 Mo 4d 态的密度相关，计算出的能量势垒可以线性相关。此外，DFT 结果表明，亚表面原子（例如碳）可以降低反应势垒。另外，我们注意到，Mo(2)C(100)和 MoN(100)上 C-N 键断裂的活化能与 Pt(100)上的相似，这表明过渡金属碳化物和氮化物对 CH(3)NH(2)中 C-N 键断裂的催化性能可能与昂贵的铂族金属非常相似。
