▎ 摘　　要

The mechanism of CH4 dissociation and carbon nucleation process on the Fe doped Cu(100) surface were investigated systematically by using the density functional theory (DFT) calculations and microkinetic model. The activity of the Cu(100) surface was improved by the doped Fe atom and the atomic Fe on the Fe-Cu(100) surface was the reaction center due to the synergistic effect. In the dissociation process of CH4, CH3 -> CH2 + H was regarded as the rate-determining step. The results obtained from the microkinetic model showed that the coverage of CHx(x = 1-3) was gradually decreased with the temperature increasing and CH3 was always the major intermediate at the broad range of the temperature (from 1035 to 1080 degrees C) and the ratio of H-2/CH4 (from 0 to 5). It is also found that the reaction rates were increased with the temperature increasing. However, the reaction rates were reduced (or increased) at the range of H-2/CH4 = 0-0.2 (or H-2/CH4 > 0.2). It is noted that controlling the H-2 partial pressure was an effective method to regulate the major intermediates and reaction rates of CH4 dissociation and further influence the growing process of graphene. (C) 2017 Elsevier B.V. All rights reserved.