Study on the Adsorption Properties and Mechanisms of CO on Nickel Surfaces Based on Density Functional Theory

In this work, the adsorption of CO onto the surface of the transition metal Ni at different coverage levels was explored based on the density functional theory (DFT). The corresponding periodic slab plate models were established, and the adsorption parameters and CO electronic states on different nickel surfaces under different coverage (0.11 mL, 0.25 mL and 0.5 mL) were calculated. The results showed that the most stable adsorption sites on Ni (111) and Ni (100) crystal surfaces were valley sites, while the most stable adsorption sites on a Ni (110) surface was a short bridge site. By comparing the energy of the same adsorption sites, it was found that the adsorption of CO on a Ni (100) crystal surface was superior to the other two surfaces. Furtherly, from the perspective of the electronic structure, the density of states (DOSs) of Ni atoms and CO molecules were calculated before and after adsorption. The density of states showed that the main factor of surface adsorption generation originates from hybridization among the orbitals. This article provides insight into the mechanisms of the nickel adsorption of CO.