▎ 摘　　要

Besides carbon solubility, the carbide formation possibility is another important factor to differentiate various substrate materials in graphene growth. A recent experiment indicates that the formation of transition metal carbides (TMCs) can suppress carbon precipitation. In this study, Mo2C, a representative of TMCs, is used to study the effects of carbide formation in graphene growth from first principles. Carbon diffusion in Mo2C bulk turns out to be very difficult and it becomes much easier on the Mo2C(001) surface. Therefore, carbon precipitation suppression and graphene growth can be realized simultaneously. A direction depended diffusion behavior is observed on the Mo2C(101) surface, which makes it less favorable for graphene growth compared to the (001) surface.