First principles study of H<sub>2</sub> dissociation, H and O atom diffusion behavior on γ-U (100) surface with Mo doping

<sec>As an important uranium alloy, U-Mo alloy has excellent mechanical properties, structural stability and thermal conductivity, which is nuclear reactor fuel tank armor. However, there exists a serious of fundamental problems need solving for practical applications. easily subjected to surface corrosion small molecules including the H<sub>2</sub>, O<sub>2</sub>, H<sub>2</sub>O, CO<sub>2</sub> . The hydrogen oxidation will have significant influence on it. In order further investigate reaction mechanism, based density functional theory transition state algorithm, first principles calculation γ-U (100) with Mo atom doping coating carried out.</sec><sec>Firstly, minimum energy path H<sub>2</sub> molecule calculated dissociation adsorption Mo-U 4Mo-U surface. Secondly, states H O atoms are studied during diffusing between adjacent most stable sites. Thirdly, bulk phase diffusion investigated relationship analyzed height in diffusion.</sec><sec>The results show that when adsorbed at configuration top horizontal position, needs overcome barrier triggering off H-H bond-broken then bridge site by neighboring atoms. higher than Mo-U. Meanwhile, lower required diffuse Mo-U, so it can be adsorbed, dissociated diffused quickly, forming film Furthermore, both cross into body phase, chemical bonds staying stably finally.</sec><sec>In this paper, we comprehensively analyze initial stage uranium-molybdenum theoretical studies. lay foundation theoretically exploring mechanism They provide support investigating burn-in predicting material properties under extreme special environment, providing reference research resistance alloy.</sec>