The density functional theory (DFT) is applied to predict elemental mercury (Hg-0) adsorption on CoMnO3 surface for the first time. GGA/PBE functional were selected to determine the potential Hg capture mechanisms. The results show that Hg has good affinity with CoMnO3 surfaces with chemical adsorption. The adsorption energy of Hg-0-CoMnO3 (1 0 0), Hg-0-CoMnO3 (1 0 1) and Hg-0-CoMnO3 (1 1 0) are -85.225, -72.305 and -70.729 kJ/mol, respectively. The Hg-Mn and Hg-Co mechanisms were revealed on low index surfaces. Hg-0 was oxidized to its valence state of 0.236 on Mn site in CoMnO3 (1 0 0) surface. The Hg-Co interaction mechanism occurred on Hg-0-CoMnO3 (1 0 1) and Hg-0-CoMnO3 (1 10) with 0.209e(-) and 0.189e(-) transformation, respectively. The PDOS analysis shows that Hg-Mn interaction depends on the hybridization of Hg(s- and d-orbitals) and Mn (s-, p- and d- orbitals). However, Hg-Co interaction stems from s- and d- orbitals of Hg, which only overlapping with d- and p- orbital of Co. Both the adsorption energy and electronic structure analysis indicated that CoMnO3 catalyst performed excellent in Hg-0 oxidation. Exposing CoMnO3 (1 0 0) is most favorable in Hg-0 control, which provides theoretical instruction on certain crystal plane synthesis in experiment. (C) 2017 Elsevier B.V. All rights reserved.