Adsorption Study of Water Vapor Molecule on Metal Pu Surface by Quantum Mechanism Computation

Employing density functional method(B3LYP) with the relativistic effective core potential(RECP) for Pu atom and all-electron basis set aug-cc-pVTZ for O and H atoms,the equilibrium geometrical structures of PuO2 molecule were optimized.In addition,four structures for Pu-water were proposed and studied.The results indicate that water molecule tends to dissociate to form more stable structure with Pu.Due to the lager difference of electronegativity for Pu and O atoms,the stable structure is from the interaction of Pu and O atoms.The thermodynamic functions of adsorption and dissociation reactions of Pu and H2O were calculated according to electronic-vibration approximation.The results show that the water vapor molecule can't adsorb on Pu surface even at low temperature,in contrast,dissociation reactions of H2O on Pu surface can occur spontaneously.