{"title":"过氧化物表面铬和钠中毒的起始反应机制","authors":"Mengren Bill Liu, Bilge Yildiz","doi":"10.1021/acs.chemmater.4c01936","DOIUrl":null,"url":null,"abstract":"Perovskite oxides serve as oxygen electrode materials in solid oxide fuel and electrolysis cells. These compounds are susceptible to poisoning by volatile chromium and sulfur species in the gas environment. The reaction mechanism of chromium and sulfur poisoning on perovskite oxide surfaces as a function of surface chemistry has not been resolved to date. Understanding the role of different surface chemistries in this degradation mechanism can help to guide the engineering of more stable surfaces. In this study, we take a state-of-the-art perovskite oxide (ABO<sub>3</sub>), La<sub>0.6</sub>Sr<sub>0.4</sub>Co<sub>0.2</sub>Fe<sub>0.8</sub>O<sub>3</sub> (LSCF), as a model oxygen electrode material. We investigate the onset of poisoning reactions by CrO<sub>3</sub> and SO<sub>2</sub>, and their activity on different surface terminations of LSCF by density functional theory (DFT) calculations and <i>ab initio</i> molecular dynamics (AIMD) simulations. We find that both CrO<sub>3</sub> and SO<sub>2</sub> molecules bind more strongly onto the AO-terminated surfaces than do the BO<sub>2</sub> surfaces. AO-terminated LSCF surfaces, especially the Sr sites, result in more strongly adsorbed species with reduced mobility at the surface. The adsorption of CrO<sub>3</sub> and SO<sub>2</sub> on Sr sites of an AO-terminated LSCF surface forms atomic coordinations similar to SrCrO<sub>4</sub> and SrSO<sub>4</sub>, thereby serving as nucleation sites for the formation of these secondary phases. We find two physical traits, surface oxygen Bader charge and subsurface oxygen 2p-band center, that correlate with the distinctly different adsorption energies of these species on the AO- and BO<sub>2</sub>-terminated surfaces. This indicates that the electrostatic interaction and charge transfer between the adsorbate and the surface play a major role in the onset of these poisoning reactions on perovskite oxides. The results reveal the role of surface chemistry in affecting the thermodynamics and the kinetics of CrO<sub>3</sub> and SO<sub>2</sub> reactions at perovskite oxide surfaces and inform effective strategies for mitigation.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":7.2000,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Onset Reaction Mechanism of Cr and S Poisoning on Perovskite Oxide Surfaces\",\"authors\":\"Mengren Bill Liu, Bilge Yildiz\",\"doi\":\"10.1021/acs.chemmater.4c01936\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Perovskite oxides serve as oxygen electrode materials in solid oxide fuel and electrolysis cells. These compounds are susceptible to poisoning by volatile chromium and sulfur species in the gas environment. The reaction mechanism of chromium and sulfur poisoning on perovskite oxide surfaces as a function of surface chemistry has not been resolved to date. Understanding the role of different surface chemistries in this degradation mechanism can help to guide the engineering of more stable surfaces. In this study, we take a state-of-the-art perovskite oxide (ABO<sub>3</sub>), La<sub>0.6</sub>Sr<sub>0.4</sub>Co<sub>0.2</sub>Fe<sub>0.8</sub>O<sub>3</sub> (LSCF), as a model oxygen electrode material. We investigate the onset of poisoning reactions by CrO<sub>3</sub> and SO<sub>2</sub>, and their activity on different surface terminations of LSCF by density functional theory (DFT) calculations and <i>ab initio</i> molecular dynamics (AIMD) simulations. We find that both CrO<sub>3</sub> and SO<sub>2</sub> molecules bind more strongly onto the AO-terminated surfaces than do the BO<sub>2</sub> surfaces. AO-terminated LSCF surfaces, especially the Sr sites, result in more strongly adsorbed species with reduced mobility at the surface. The adsorption of CrO<sub>3</sub> and SO<sub>2</sub> on Sr sites of an AO-terminated LSCF surface forms atomic coordinations similar to SrCrO<sub>4</sub> and SrSO<sub>4</sub>, thereby serving as nucleation sites for the formation of these secondary phases. We find two physical traits, surface oxygen Bader charge and subsurface oxygen 2p-band center, that correlate with the distinctly different adsorption energies of these species on the AO- and BO<sub>2</sub>-terminated surfaces. This indicates that the electrostatic interaction and charge transfer between the adsorbate and the surface play a major role in the onset of these poisoning reactions on perovskite oxides. The results reveal the role of surface chemistry in affecting the thermodynamics and the kinetics of CrO<sub>3</sub> and SO<sub>2</sub> reactions at perovskite oxide surfaces and inform effective strategies for mitigation.\",\"PeriodicalId\":33,\"journal\":{\"name\":\"Chemistry of Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":7.2000,\"publicationDate\":\"2024-10-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemistry of Materials\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://doi.org/10.1021/acs.chemmater.4c01936\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemistry of Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1021/acs.chemmater.4c01936","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
摘要
过氧化物氧化物是固体氧化物燃料和电解池中的氧电极材料。这些化合物容易受到气体环境中挥发性铬和硫物种的毒害。铬和硫在包晶氧化物表面的中毒反应机制与表面化学的关系迄今尚未解决。了解不同表面化学成分在降解机制中的作用有助于指导更稳定表面的工程设计。在本研究中,我们以最先进的包晶氧化物(ABO3)--La0.6Sr0.4Co0.2Fe0.8O3(LSCF)--为模型氧电极材料。我们通过密度泛函理论(DFT)计算和原子分子动力学(AIMD)模拟,研究了 CrO3 和 SO2 的中毒反应起始点及其在 LSCF 不同表面终端的活性。我们发现,与 BO2 表面相比,CrO3 和 SO2 分子在 AO 端面的结合力更强。AO 端面的 LSCF 表面,尤其是 Sr 位点,会产生更强的吸附物种,同时降低表面的流动性。在 AO 端 LSCF 表面的锶位点上吸附 CrO3 和 SO2 会形成类似于 SrCrO4 和 SrSO4 的原子配位,从而成为形成这些次生相的成核位点。我们发现了两个物理特征,即表面氧巴德电荷和次表面氧 2p 带中心,它们与这些物种在 AO 端面和 BO2 端面截然不同的吸附能相关联。这表明,吸附物与表面之间的静电相互作用和电荷转移在包晶氧化物上这些中毒反应的发生过程中起着重要作用。研究结果揭示了表面化学在影响包晶氧化物表面氧化铬和二氧化硫反应的热力学和动力学方面的作用,并为有效的缓解策略提供了参考。
Onset Reaction Mechanism of Cr and S Poisoning on Perovskite Oxide Surfaces
Perovskite oxides serve as oxygen electrode materials in solid oxide fuel and electrolysis cells. These compounds are susceptible to poisoning by volatile chromium and sulfur species in the gas environment. The reaction mechanism of chromium and sulfur poisoning on perovskite oxide surfaces as a function of surface chemistry has not been resolved to date. Understanding the role of different surface chemistries in this degradation mechanism can help to guide the engineering of more stable surfaces. In this study, we take a state-of-the-art perovskite oxide (ABO3), La0.6Sr0.4Co0.2Fe0.8O3 (LSCF), as a model oxygen electrode material. We investigate the onset of poisoning reactions by CrO3 and SO2, and their activity on different surface terminations of LSCF by density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations. We find that both CrO3 and SO2 molecules bind more strongly onto the AO-terminated surfaces than do the BO2 surfaces. AO-terminated LSCF surfaces, especially the Sr sites, result in more strongly adsorbed species with reduced mobility at the surface. The adsorption of CrO3 and SO2 on Sr sites of an AO-terminated LSCF surface forms atomic coordinations similar to SrCrO4 and SrSO4, thereby serving as nucleation sites for the formation of these secondary phases. We find two physical traits, surface oxygen Bader charge and subsurface oxygen 2p-band center, that correlate with the distinctly different adsorption energies of these species on the AO- and BO2-terminated surfaces. This indicates that the electrostatic interaction and charge transfer between the adsorbate and the surface play a major role in the onset of these poisoning reactions on perovskite oxides. The results reveal the role of surface chemistry in affecting the thermodynamics and the kinetics of CrO3 and SO2 reactions at perovskite oxide surfaces and inform effective strategies for mitigation.
期刊介绍:
The journal Chemistry of Materials focuses on publishing original research at the intersection of materials science and chemistry. The studies published in the journal involve chemistry as a prominent component and explore topics such as the design, synthesis, characterization, processing, understanding, and application of functional or potentially functional materials. The journal covers various areas of interest, including inorganic and organic solid-state chemistry, nanomaterials, biomaterials, thin films and polymers, and composite/hybrid materials. The journal particularly seeks papers that highlight the creation or development of innovative materials with novel optical, electrical, magnetic, catalytic, or mechanical properties. It is essential that manuscripts on these topics have a primary focus on the chemistry of materials and represent a significant advancement compared to prior research. Before external reviews are sought, submitted manuscripts undergo a review process by a minimum of two editors to ensure their appropriateness for the journal and the presence of sufficient evidence of a significant advance that will be of broad interest to the materials chemistry community.