Density functional study of H2 molecule and H atom adsorption on α-U(001) surface

Density functional theory method has been employed to investigate the adsorption of H-2 molecule and H atom on alpha-U(001) surface. There exist four initial sites [top (A), triangle-center (B), long-bridge (C), and short-bridge (D)] for H-2 and H atom adsorptions on alpha-U(001) surface. The E-ads (adsorption energy) values on the top sites of H-2-U(001) configurations are around -0.666 eV, and H-2 molecule has been elongated but not broken into H atoms. For the other three sites, the Eads values are around -1.521 eV. The long-bridge site is the most reactive site for H2 decomposing. For the H-U(001) configurations, the Eads are around -2.904 eV. Top site and short-bridge site are the most reactive sites for the H atom react on the alpha-U(001) surface. Our work reveals that the different reactive sites play discrepant effects on hydrogenation process. Geometric deformations, diffusion paths, and partial density of states of H-2-U(001) and H-U(001) configurations have also been analyzed. Copyright (C) 2016 John Wiley & Sons, Ltd.