The chemisorption thermodynamics of O$_2$ and H$_2$O on AFM UO$_2$ surfaces unraveled by DFT+U-D3 study

Yang Huang; Le Zhang; Hefei Ji; Zhipeng Zhang; Qili Zhang; Bo Sun; Haifeng Liu; Haifeng Song

paper

The chemisorption thermodynamics of O $_{2}$ and H $_{2}$ O on AFM UO $_{2}$ surfaces unraveled by DFT+U-D3 study

arXiv:2502.08078

Abstract

Unraveling the adsorption mechanism and thermodynamics of O $_{2}$ and H $_{2}$ O on uranium dioxide surfaces is critical for the nuclear fuel storage and uranium corrosion. Based on the first-principles DFT+U-D3 calculations, we carefully test the effect of antiferromagnetic order arrangements on the thermodynamic stability of UO $_{2}$ surfaces and propose the 1k AFM surface computational model. The chemisorption states of O $_{2}$ and H $_{2}$ O on UO $_{2}$ (111) surface, suggested by previous experiments, are accurately calculated for the first time. The adsorption properties of O $_{2}$ and H $_{2}$ O on UO $_{2}$ (111) and (110) surfaces are discussed in detail to reveal the different interaction mechanisms. Combined with ab initio atomistic thermodynamics method, we systematically calculate the chemisorption phase diagram and isotherm of O $_{2}$ and H $_{2}$ O on UO $_{2}$ surfaces. Due to the different intermolecular interactions, the monolayer and multilayer adsorption models are identified for O $_{2}$ and H $_{2}$ O, respectively. This study has comprehensively revealed the different adsorption mechanisms of O $_{2}$ and H $_{2}$ O on UO $_{2}$ surfaces, bridging the electronic structure calculations to the interpretation of experimental results and providing a solid foundation for future theoretical studies of uranium corrosion mechanism in humid air.

The chemisorption thermodynamics of O2​ and H2​O on AFM UO2​ surfaces unraveled by DFT+U-D3 study

Abstract

The chemisorption thermodynamics of O $_{2}$ and H $_{2}$ O on AFM UO $_{2}$ surfaces unraveled by DFT+U-D3 study