Structural and electronic properties of cobalt carbide Co2C and its surface stability: Density functional theory study

► DFT calculations of the structural and electronic properties of bulk Co2C and the stability of low index Co2C surfaces. ► Co2C is metastable in Fischer-Tropsch synthesis. ► The low index stoichiometric surfaces of Co2C have the decreased stability order of (101) > (011) > (010) > (110) > (100) > (001) = (111). ► Non-stoichiometric terminations of the low index (011) and (111) surfaces might be energetically more favorable under reaction conditions.