▎ 摘　　要

In order to realize the sulfur and water resistance and facilitate the CO oxidation reactions, the effects of strain on the adsorption of CO, O 2 , SO2 and H2O molecules on Ni single-atom-catalyst supported by single-carbon-vacancy graphene (Ni-SG) have been studied based on first principles calculations. It shows that the compressive strain increases the adsorption energies of all above mentioned molecules on Ni-SG, where SO2 is adsorbed more strongly on Ni-SG than CO. However, in the presence of tensile strain, the adsorption energies decreases significantly when the molecules (O 2 and SO2) obtain electrons from Ni-SG, while the adsorption energies just slightly decrease when the molecules (CO and H2O) lose electrons to Ni-SG, which finally achieves the preferential adsorption of CO and O 2 molecules on Ni-SG by tensile strain. In addition, with tensile strain increasing to 10%, the rate-limited energy barrier along Eley-Rideal (ER) path monotonically increases from 0.77 eV to 0.98 eV, while the rate-limited energy barrier along Langmuir-Hinshelwood (LH) path monotonically decreases from 0.54 eV to 0.44 eV, indicating that the tensile strain can facilitate the LH mechanism while imped the ER mechanism on Ni-SG. The Hirshfeld charge and orbital levels of O 2 and CO molecules are modulated by the tensile strain, which plays an im-portant role for the decreasing of energy barriers for CO oxidation. Overall, the tensile strain can enhance the sulfur and water resistance of Ni-SG, as well as boost the CO oxidation reactions.(c) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.