First-principles study of water reacting with the (110) surface of uranium mononitride

• Published in: Journal of nuclear materials Vol. 492; pp. 244 - 252
• Main Authors: Bo, Tao, Lan, Jian-Hui, Zhao, Yao-Lin, He, Chao-Hui, Chai, Zhi-Fang, Shi, Wei-Qun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2017; Elsevier BV
• Subjects: ab initio atomistic thermodynamic; Adsorption; Alternative energy sources; Energy; Energy shortages; First principles; Surface adsorption; Surface chemistry; Thermodynamics; Uranium; Uranium mononitride; Water; Surface adsorption; Water; First principles; ab initio atomistic thermodynamic; Uranium mononitride
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2017.05.026

The adsorption and dissociation behaviors of water on the UN (110) surface have been investigated by using DFT + U method in combination with ab initio atomistic thermodynamic simulations. The most stable adsorption site for H, O, and OH adsorption is the uranium bridge site. For a water monomer, the adsorption energies are −0.90, −3.23, and −4.46 eV for the most stable molecular, partially dissociative, and completely dissociative adsorption, respectively. The dissociation of water from H2O to OH and H has a very small energy barrier, while from OH to O and H has a high energy barrier of 1.63 eV. The coverage dependence for molecular adsorption is not obvious, while for partially dissociative and completely dissociative adsorption, the coverage dependence is quite obvious. Besides, we have investigated the adsorption of water under different temperature and pressure conditions by using the “ab initio atomistic thermodynamic” method. [Display omitted]