Ab initio thermodynamic and kinetic modeling of molecular adsorption and reaction properties on PuO2(111) surface under exposure to environmental gases

IF 2.1 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science Pub Date : 2024-03-16 DOI:10.1016/j.susc.2024.122482

Jinfan Chen , Jun Tang , Pengchuang Liu , Ruizhi Qiu

{"title":"Ab initio thermodynamic and kinetic modeling of molecular adsorption and reaction properties on PuO2(111) surface under exposure to environmental gases","authors":"Jinfan Chen , Jun Tang , Pengchuang Liu , Ruizhi Qiu","doi":"10.1016/j.susc.2024.122482","DOIUrl":null,"url":null,"abstract":"<div>Adsorption and reaction properties of environmental gases including O2, H2, and H2O on the PuO2(111) surface were studied via density functional theory simulations along with thermodynamic and kinetic analysis. Simulation results show that the stoichiometric PuO2(111) remains intact under O2 atmosphere and extremely low or high O2 pressure is required to form oxygen vacancy or adsorbed-O on the surface. The H2O prefers to stay as molecular state when adsorbing on PuO2(111) and a relatively high humidity is required for H2O to be stably binding on the surface. For H2 interaction with PuO2, the dissociative adsorption of H2 molecule induces reduction of Pu(IV) ions to Pu(III), and remains thermodynamically stable at H2 pressure as low as ∼10−35 bar under room temperature. Kinetic modeling shows that at temperature below 350 K, the PuO2(111) surface is mainly covered by OH species when exposing to H2 environment while bare metal sites appear with increased temperature and reaction time.</div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1000,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Surface Science","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0039602824000335","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}

引用次数: 0

Abstract

Adsorption and reaction properties of environmental gases including O₂, H₂, and H₂O on the PuO₂(111) surface were studied via density functional theory simulations along with thermodynamic and kinetic analysis. Simulation results show that the stoichiometric PuO₂(111) remains intact under O₂ atmosphere and extremely low or high O₂ pressure is required to form oxygen vacancy or adsorbed-O on the surface. The H₂O prefers to stay as molecular state when adsorbing on PuO₂(111) and a relatively high humidity is required for H₂O to be stably binding on the surface. For H₂ interaction with PuO₂, the dissociative adsorption of H₂ molecule induces reduction of Pu(IV) ions to Pu(III), and remains thermodynamically stable at H₂ pressure as low as ∼10⁻³⁵ bar under room temperature. Kinetic modeling shows that at temperature below 350 K, the PuO₂(111) surface is mainly covered by OH species when exposing to H₂ environment while bare metal sites appear with increased temperature and reaction time.

Abstract Image

查看原文本刊更多论文

暴露于环境气体时 PuO2(111) 表面分子吸附和反应特性的 Ab initio 热力学和动力学建模

通过密度泛函理论模拟以及热力学和动力学分析，研究了环境气体（包括 O2、H2 和 H2O）在 PuO2(111) 表面的吸附和反应特性。模拟结果表明，在 O2 气氛下，化学计量的 PuO2(111) 保持不变，需要极低或极高的 O2 压力才能在表面形成氧空位或吸附-O。H2O 吸附在 PuO2(111) 上时更喜欢保持分子状态，因此需要相对较高的湿度才能使 H2O 稳定地结合在表面。在 H2 与 PuO2 的相互作用中，H2 分子的离解吸附导致 Pu(IV) 离子还原为 Pu(III)，并且在室温下 H2 压力低至 ∼10-35 bar 时保持热力学稳定。动力学模型显示，在温度低于 350 K 时，PuO2(111)表面在暴露于 H2 环境时主要被 OH 物种覆盖，而随着温度和反应时间的增加，会出现裸金属位点。

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

Surface Science 化学-物理：凝聚态物理

CiteScore

3.30

自引率

5.30%

发文量

137

审稿时长

25 days

期刊介绍： Surface Science is devoted to elucidating the fundamental aspects of chemistry and physics occurring at a wide range of surfaces and interfaces and to disseminating this knowledge fast. The journal welcomes a broad spectrum of topics, including but not limited to: • model systems (e.g. in Ultra High Vacuum) under well-controlled reactive conditions • nanoscale science and engineering, including manipulation of matter at the atomic/molecular scale and assembly phenomena • reactivity of surfaces as related to various applied areas including heterogeneous catalysis, chemistry at electrified interfaces, and semiconductors functionalization • phenomena at interfaces relevant to energy storage and conversion, and fuels production and utilization • surface reactivity for environmental protection and pollution remediation • interactions at surfaces of soft matter, including polymers and biomaterials. Both experimental and theoretical work, including modeling, is within the scope of the journal. Work published in Surface Science reaches a wide readership, from chemistry and physics to biology and materials science and engineering, providing an excellent forum for cross-fertilization of ideas and broad dissemination of scientific discoveries.