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Investigation into the state and mechanisms of the active metal substitution into the γ-Al₂O₃ support is the basis for design of many catalysts. Periodic density functional theory (DFT) +U calculations were used to investigate the surface properties of transition metals Co³⁺ and Ni³⁺ cations substitute for the Al³⁺ cations of γ-Al₂O₃ (110) surface. It was found that the substitution energy of one Al³⁺ substituted by Co³⁺ and Ni³⁺ are −61 and −57 kJ/mol, respectively. The Co and Ni preferentially substitute the tetrahedral Al sites instead of the octahedral Al sites. Using thermodynamics, the Al atoms in the top layer of γ-Al₂O₃ (110) can be 100% substituted by Co and Ni. Ni is easier to substitute the Al atom than Co. There is no obvious structural distortion that occurs after Co and Ni substituted all the top layer Al atoms. While the band gaps of the substituted surface become narrower, resulting in the increase of surface Lewis acidity. In addition, the oxygen vacancy formation energies of the Co and Ni substituted surface are 268 and 53 kJ/mol, respectively. The results provide interface structure and physical chemistry properties of metal-doped catalysts.