Adsorption and dissociation of H2 on PuO2 (110) surface: A density functional theory study

Abstract

The adsorption and dissociation of H2 on PuO2 (110) surface have been investigated by density functional theory corrected for onsite Coulombic interactions (GGA + U). In order to find out the energetically more favorable adsorption site and optimum dissociation path, adsorption energy of hydrogen on various sites and the dissociation energy barrier are derived and compared. The results show that H2 molecules are weakly adsorbed on PuO2 (110) surface, while H atoms are strongly bonded at the top of O atom sites. One possible dissociation pathway of H2 molecule is investigated using the climbing nudged-elastic-band (cNEB) approach. Favorable dissociation energy barrier is 0.48 eV. The calculated barriers show that the dissociation of H2 molecule on PuO2 (110) surface is kinetically the most favorable and can occur even below room temperature.