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采用密度泛函理论对NO+CO反应机理在Au(111)面上的反应历程进行详细讨论。通过对表面吸附物种(N、O、NO、CO、N_2、N_2O、CO_2)的吸附行为进行研究,得到最佳活性吸附中心。对三种机理中的基元反应的活化能进行计算分析,结果发现由于NO在Au(111)面上直接分解为N和O需要很高的能垒(599.4 kJ·mol~(-1)),NO+CO反应按照直接分解机理的可能性很小,按照二聚体机理的可能性更大。最佳反应途径是2NO→(NO)2→N2O+O→N2+2O,其中通过O端吸附在Au(111)面上的二聚体(NO)_2是不可避免的中问体。该反应的决速步骤是N_2O~*→N_2~*+O~*,活化能为49.5 kJ·mol~(-1)。
The reaction mechanism of NO + CO reaction on Au (111) surface is discussed in detail by using density functional theory. Adsorption behavior of surface adsorbed species (N, O, NO, CO, N 2, N 2 O, CO 2) was studied to obtain the best active adsorption center. Calculating the activation energies of the elementary reactions in the three mechanisms, we found that NO requires a high energy barrier (599.4 kJ · mol -1) due to the direct decomposition of NO into N and O on Au (111) , NO + CO reaction in accordance with the direct decomposition mechanism is unlikely, according to the dimer mechanism is more likely. The best reaction pathway is 2NO → (NO) 2 → N2O + O → N2 + 2O, in which the dimer (NO) 2 adsorbed on the Au (111) surface via the O side is an inevitable interrogation. The rate-determining step of the reaction is N 2 O * * N 2 ~ * + O *, and the activation energy is 49.5 kJ · mol -1.