First-principles investigation of water adsorption on FeCrAl (1 1 0) surfaces

Using the first-principles calculations, the adsorption of the water on the FeCrAl surfaces is studied based on the density functional theory. The atomic structure of various configurations of water adsorption on the (1 1 0) surface is studied. Compared with the Zr (0 0 0 1) system which is widely used as the reactor cladding material, the FeCrAl (1 1 0) surface shows lower adsorption energy. The calculated results show that top site adsorption is energy favorable compared with the hollow and bridge sites. Besides, the charge transfer induced by the adsorption of water is studied as well as the electron density. It is found that charge accumulation happens around water molecules while charge depletion occurs the around surface metal atoms after the water adsorption. The surface element effect on the on the adsorption has been studied in details, and the Cr element on the surface shows stronger interaction with water compared with the Fe or Al elements. Furthermore, the water dissociation calculations show that the FeCrAl alloy has similar energy barrier value on the (1 1 0) surface compared with the pure Fe(1 1 0) surface. FeCrAl alloy has exhibited excellent potential serving as a good candidate for the cladding materials from the aspect of water adsorption.