Yu Wang, Paul Paciok, Lukas Pielsticker, Wei Wang, Alexander Spriewald Luciano, Min Ding, Lorena Glatthaar, Walid Hetaba, Yanglong Guo*, Jaime Gallego*, Bernd M. Smarsly* and Herbert Over*,
{"title":"从显微镜观察 LaFe0.9Ru0.1O3 包晶中的钌溶出现象","authors":"Yu Wang, Paul Paciok, Lukas Pielsticker, Wei Wang, Alexander Spriewald Luciano, Min Ding, Lorena Glatthaar, Walid Hetaba, Yanglong Guo*, Jaime Gallego*, Bernd M. Smarsly* and Herbert Over*, ","doi":"10.1021/acs.chemmater.4c01084","DOIUrl":null,"url":null,"abstract":"<p >Metal exsolution is a smart strategy that allows modification and enrichment of a material’s surface with highly active catalytic phases, thus offering the possibility to fine-tune the surface chemical composition. We study the exsolution of Ru from a perovskite solid solution LaFe<sub>0.9</sub>Ru<sub>0.1</sub>O<sub>3</sub> (LFRO) to form Ru nanoparticles and their passivation by a conforming LaO<sub><i>x</i></sub> layer by applying a variety of <i>in situ</i> techniques, including TEM and XPS, in combination with <i>ex situ</i> infrared and Raman spectroscopy, but most notably by utilizing the catalytic propane combustion to probe the formation of the passivating LaO<sub><i>x</i></sub> layer. During the Ru exsolution process, Ru<sup>3+</sup> in LFRO is reduced first to the Ru<sup>β</sup> species and subsequently into a Ru<sup>0</sup> species, evidencing the exsolution of Ru particle. The transformation of Ru<sup>3+</sup> → Ru<sup>β</sup> proceeds already below 300 °C and is correlated with the formation of oxygen vacancies under a reductive atmosphere. The subsequent transformation of Ru<sup>β</sup> toward Ru<sup>0</sup> needs at least a reduction temperature of 400 °C that is likely to be determined by the diffusion of Ru<sup>3+</sup> from the near-surface region of LFRO toward the surface. Only above 600 °C ruthenium cations from the bulk of LFRO are exsolved, leading to the further growth of Ru particles. Around 600 °C, the exsolution of Ru particles is accompanied by the formation of a covering LaO<sub><i>x</i></sub> layer. We propose that La segregation and precipitation as surface LaO<sub><i>x</i></sub> are driven by the overstoichiometry of La in LFRO after Ru exsolution.</p>","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":7.2000,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Microscopic Insight into Ruthenium Exsolution from LaFe0.9Ru0.1O3 Perovskite\",\"authors\":\"Yu Wang, Paul Paciok, Lukas Pielsticker, Wei Wang, Alexander Spriewald Luciano, Min Ding, Lorena Glatthaar, Walid Hetaba, Yanglong Guo*, Jaime Gallego*, Bernd M. Smarsly* and Herbert Over*, \",\"doi\":\"10.1021/acs.chemmater.4c01084\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >Metal exsolution is a smart strategy that allows modification and enrichment of a material’s surface with highly active catalytic phases, thus offering the possibility to fine-tune the surface chemical composition. We study the exsolution of Ru from a perovskite solid solution LaFe<sub>0.9</sub>Ru<sub>0.1</sub>O<sub>3</sub> (LFRO) to form Ru nanoparticles and their passivation by a conforming LaO<sub><i>x</i></sub> layer by applying a variety of <i>in situ</i> techniques, including TEM and XPS, in combination with <i>ex situ</i> infrared and Raman spectroscopy, but most notably by utilizing the catalytic propane combustion to probe the formation of the passivating LaO<sub><i>x</i></sub> layer. During the Ru exsolution process, Ru<sup>3+</sup> in LFRO is reduced first to the Ru<sup>β</sup> species and subsequently into a Ru<sup>0</sup> species, evidencing the exsolution of Ru particle. The transformation of Ru<sup>3+</sup> → Ru<sup>β</sup> proceeds already below 300 °C and is correlated with the formation of oxygen vacancies under a reductive atmosphere. The subsequent transformation of Ru<sup>β</sup> toward Ru<sup>0</sup> needs at least a reduction temperature of 400 °C that is likely to be determined by the diffusion of Ru<sup>3+</sup> from the near-surface region of LFRO toward the surface. Only above 600 °C ruthenium cations from the bulk of LFRO are exsolved, leading to the further growth of Ru particles. Around 600 °C, the exsolution of Ru particles is accompanied by the formation of a covering LaO<sub><i>x</i></sub> layer. We propose that La segregation and precipitation as surface LaO<sub><i>x</i></sub> are driven by the overstoichiometry of La in LFRO after Ru exsolution.</p>\",\"PeriodicalId\":33,\"journal\":{\"name\":\"Chemistry of Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":7.2000,\"publicationDate\":\"2024-06-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemistry of Materials\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acs.chemmater.4c01084\",\"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://pubs.acs.org/doi/10.1021/acs.chemmater.4c01084","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}
Microscopic Insight into Ruthenium Exsolution from LaFe0.9Ru0.1O3 Perovskite
Metal exsolution is a smart strategy that allows modification and enrichment of a material’s surface with highly active catalytic phases, thus offering the possibility to fine-tune the surface chemical composition. We study the exsolution of Ru from a perovskite solid solution LaFe0.9Ru0.1O3 (LFRO) to form Ru nanoparticles and their passivation by a conforming LaOx layer by applying a variety of in situ techniques, including TEM and XPS, in combination with ex situ infrared and Raman spectroscopy, but most notably by utilizing the catalytic propane combustion to probe the formation of the passivating LaOx layer. During the Ru exsolution process, Ru3+ in LFRO is reduced first to the Ruβ species and subsequently into a Ru0 species, evidencing the exsolution of Ru particle. The transformation of Ru3+ → Ruβ proceeds already below 300 °C and is correlated with the formation of oxygen vacancies under a reductive atmosphere. The subsequent transformation of Ruβ toward Ru0 needs at least a reduction temperature of 400 °C that is likely to be determined by the diffusion of Ru3+ from the near-surface region of LFRO toward the surface. Only above 600 °C ruthenium cations from the bulk of LFRO are exsolved, leading to the further growth of Ru particles. Around 600 °C, the exsolution of Ru particles is accompanied by the formation of a covering LaOx layer. We propose that La segregation and precipitation as surface LaOx are driven by the overstoichiometry of La in LFRO after Ru exsolution.
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.