The role of pre-adsorbed hydrogen in facilitating water release at the Li4TiO4 surface: A first-principles study

IF 2.8 2区工程技术 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Nuclear Materials Pub Date : 2025-04-11 DOI:10.1016/j.jnucmat.2025.155823

Zhonghua Lu , Yanli Shi , Yuchen Liu , Huanhuan Liu , Xiuling Wang , Cong Zhang , Gaoyuan Wang , Jianqi Qi , Tiecheng Lu

{"title":"The role of pre-adsorbed hydrogen in facilitating water release at the Li4TiO4 surface: A first-principles study","authors":"Zhonghua Lu , Yanli Shi , Yuchen Liu , Huanhuan Liu , Xiuling Wang , Cong Zhang , Gaoyuan Wang , Jianqi Qi , Tiecheng Lu","doi":"10.1016/j.jnucmat.2025.155823","DOIUrl":null,"url":null,"abstract":"<div><div>Li<sub>4</sub>TiO<sub>4</sub> is recognized as an attractive material for tritium breeding in fusion reactors, owing to its high lithium content. Understanding the process of surface water formation is important for optimizing its tritium release performance. In this work, we conducted first-principles calculations to investigate the transformation of desorbed H<sub>2</sub> to water molecules on the Li<sub>4</sub>TiO<sub>4</sub> surface. This process encompasses the dissociative adsorption of H<sub>2</sub>, the diffusion of hydrogen atoms, the abstraction of a surface oxygen atom to form water molecules, and their subsequent release. The possible adsorption sites, local diffusion pathways, and their corresponding activation energies are identified. We determined that the global energy barrier for the transformation from desorbed H<sub>2</sub> to desorbed H<sub>2</sub>O in the pre-adsorbed hydrogen system is 1.62 eV, approximately 1 eV less than the 2.67 eV observed in the non-adsorbed hydrogen system. This reduction in the energy barrier suggests that pre-adsorbed hydrogen facilitates water release. The decrease in the energy barrier is attributed to the easier formation of oxygen vacancies on the surface in the presence of pre-adsorbed hydrogen. Our results are consistent with experimental observations that pre-adsorbed hydrogen promotes the release of tritiated water.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"612 ","pages":"Article 155823"},"PeriodicalIF":2.8000,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Nuclear Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022311525002168","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

Li₄TiO₄ is recognized as an attractive material for tritium breeding in fusion reactors, owing to its high lithium content. Understanding the process of surface water formation is important for optimizing its tritium release performance. In this work, we conducted first-principles calculations to investigate the transformation of desorbed H₂ to water molecules on the Li₄TiO₄ surface. This process encompasses the dissociative adsorption of H₂, the diffusion of hydrogen atoms, the abstraction of a surface oxygen atom to form water molecules, and their subsequent release. The possible adsorption sites, local diffusion pathways, and their corresponding activation energies are identified. We determined that the global energy barrier for the transformation from desorbed H₂ to desorbed H₂O in the pre-adsorbed hydrogen system is 1.62 eV, approximately 1 eV less than the 2.67 eV observed in the non-adsorbed hydrogen system. This reduction in the energy barrier suggests that pre-adsorbed hydrogen facilitates water release. The decrease in the energy barrier is attributed to the easier formation of oxygen vacancies on the surface in the presence of pre-adsorbed hydrogen. Our results are consistent with experimental observations that pre-adsorbed hydrogen promotes the release of tritiated water.

查看原文本刊更多论文

预吸附氢在促进 Li4TiO4 表面水释放中的作用：第一原理研究

由于Li4TiO4的高锂含量，它被认为是一种有吸引力的聚变反应堆氚增殖材料。了解地表水的形成过程对优化其氚释放性能具有重要意义。在这项工作中，我们通过第一性原理计算来研究解吸H2在Li4TiO4表面向水分子的转化。这个过程包括H2的解离吸附，氢原子的扩散，表面氧原子的抽象形成水分子，以及随后的释放。确定了可能的吸附位点、局部扩散途径及其相应的活化能。我们确定了预吸附氢体系中从解吸H2到解吸H2O的总能垒为1.62 eV，比未吸附氢体系中观察到的2.67 eV低约1 eV。这种能量势垒的减少表明，预吸附的氢促进了水的释放。能量势垒的降低是由于在预吸附氢的存在下，表面上更容易形成氧空位。我们的结果与实验观察一致，预吸附氢促进氚化水的释放。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Nuclear Materials 工程技术-材料科学：综合

CiteScore

5.70

自引率

25.80%

发文量

601

审稿时长

63 days

期刊介绍： The Journal of Nuclear Materials publishes high quality papers in materials research for nuclear applications, primarily fission reactors, fusion reactors, and similar environments including radiation areas of charged particle accelerators. Both original research and critical review papers covering experimental, theoretical, and computational aspects of either fundamental or applied nature are welcome. The breadth of the field is such that a wide range of processes and properties in the field of materials science and engineering is of interest to the readership, spanning atom-scale processes, microstructures, thermodynamics, mechanical properties, physical properties, and corrosion, for example. Topics covered by JNM Fission reactor materials, including fuels, cladding, core structures, pressure vessels, coolant interactions with materials, moderator and control components, fission product behavior. Materials aspects of the entire fuel cycle. Materials aspects of the actinides and their compounds. Performance of nuclear waste materials; materials aspects of the immobilization of wastes. Fusion reactor materials, including first walls, blankets, insulators and magnets. Neutron and charged particle radiation effects in materials, including defects, transmutations, microstructures, phase changes and macroscopic properties. Interaction of plasmas, ion beams, electron beams and electromagnetic radiation with materials relevant to nuclear systems.