First-Principles Study on Adsorption Reaction of Oxygen Molecules on Fe (110) Crystal Surface

The adsorption reaction between oxygen (O2) molecule and ferrum (Fe) (110) crystal surface in the oxidation process of Fe surface was studied by using the first-principles method. The differential charge density analysis of the adsorption sites of oxygen molecule on Fe (110) crystal surface, the calculation of adsorption energy at different sites and the analysis of electronic density of states showed that the stable adsorption position of oxygen molecule was parallel to Fe (110) crystal surface, and the oxygen atom tended to adsorb at the triangular gap of Fe atoms. The electronic structure of the adsorption system showed that the 2p electron orbital of oxygen atom plays a major role in the adsorption, and only O-Fe electron interaction exists when oxygen molecule is adsorbed in the parallel orientation, which makes the whole Fe (110) crystal surface lose electrons, increase the system potential and the risk of electrochemical corrosion. The research conclusions can provide theoretical support for the further insight in the oxidation corrosion mechanism of nuclear metal surface.