与锕系元素二氧化物（111）表面的相互作用。

Interaction of hydrogen with actinide dioxide (111) surfaces.

机构信息

Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom.

Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, Tennessee 37831, USA.

出版信息

J Chem Phys. 2019 Apr 7;150(13):134701. doi: 10.1063/1.5087577.

DOI:10.1063/1.5087577

PMID:30954055

Abstract

The interaction of atomic and molecular hydrogen with actinide dioxide (AnO, An = U, Np, Pu) (111) surfaces has been investigated by DFT+U, where noncollinear 3k antiferromagnetic behaviour and spin-orbit interactions are considered. The adsorption of atomic hydrogen forms a hydroxide group, coupled to the reduction of an actinide ion. The energy of atomic hydrogen adsorption on the UO (0.82 eV), NpO (-0.10 eV), and PuO (-1.25 eV) surfaces has been calculated. The dissociation of molecular hydrogen is not observed, shown to be due to kinetic rather than thermodynamic factors. As a barrier to the formation of a second hydroxyl group, an unusual charge distribution has been shown. This could be a limitation of a (1·1) unit cell method or an artefact of the systems. The recombination of hydrogen ions on the AnO (111) surfaces is favoured over hydroxide formation.

摘要

通过 DFT+U 方法研究了原子和分子氢与锕系二氧化物（AnO，An=U、Np、Pu）（111）表面的相互作用，其中考虑了非共线 3k 反铁磁行为和自旋轨道相互作用。原子氢的吸附形成了氢氧根基团，与锕系离子的还原相耦合。计算了原子氢在 UO（0.82 eV）、NpO（-0.10 eV）和 PuO（-1.25 eV）表面上的吸附能。未观察到分子氢的离解，表明这是由于动力学而不是热力学因素。作为形成第二个羟基的障碍，显示出一种不寻常的电荷分布。这可能是（1·1）单元方法的限制或系统的人为产物。在 AnO（111）表面上，氢离子的复合比氢氧根的形成更有利。