Theoretical Study of the Aggregation and Dissociation of Water Molecules on the ZrCo(110) Surface

The oxidation reaction between zirconium cobalt alloy ZrCo , as a tritium storage material, and gas water molecules usually leads to the poisoning and deactivation of the material surface, which greatly affects the safe operation of fusion reactors. In this article, first-principles calculation methods based on density functional theory DFT was employed to study the adsorption and dissociation behavior of various water molecule clusters on the ZrCo 110 surface. The result shows that 6H(2)O cluster forms a cyclic adsorption configuration on the surface through hydrogen bonding. As the cluster size increases, the adsorption energy of newly added molecule gradually decreases, and water clusters gradually evolve into complex double-layer water molecule adsorption configurations due to surface spatial effects. Moreover, protons can rapidly transfer between different water molecules by the hydrogen bonding in water clusters. On the other hand, water molecules are prone to chemical bond cleavage at the active sites on the ZrCo 110 surface, where the product OH mainly interacts with surface Zr atoms, while the product H adsorbs on Zr2Co threefold hollow sites. Therefore, hydrogen bonding plays a very important role in the oxidation and corrosion behavior of ZrCo 110 surface by water molecules.