{"title":"Dynamics of CeO2-supported Pt nanoparticles in CO oxidation reaction revealed by millisecond time-resolved HERFD-XANES spectroscopy†","authors":"Junya Ohyama , Mizuki Sato , Masayuki Tsushida , Keisuke Awaya , Masato Machida , Tomoya Uruga , Kotaro Higashi","doi":"10.1039/d4cy01406e","DOIUrl":null,"url":null,"abstract":"<div><div>The dynamics of CeO<sub>2</sub>-supported 1.5 nm Pt nanoparticles (Pt/CeO<sub>2</sub>) during catalysis for CO oxidation at 50 °C were observed. High-energy resolution fluorescence-detected (HERFD) Pt L<sub>3</sub>-edge X-ray absorption near-edge structure (XANES) spectroscopy with millisecond time resolution was used for this observation. A series of time-resolved spectra of Pt/CeO<sub>2</sub> during CO oxidation were fitted by linear combinations of spectra corresponding to bare, CO-adsorbed, and surface-oxidised Pt nanoparticles. The analysis revealed that after O<sub>2</sub> pulse injection into CO-adsorbed Pt nanoparticles, all adsorbed CO was oxidised within 0.5 s, forming a bare Pt surface. Subsequently, the bare Pt surface was oxidised at a much slower rate, approximately 10 s, compared with the oxidation of adsorbed CO. These findings demonstrate the utility of time-resolved HERFD-XANES spectroscopy in studying catalytic processes. This reveals variations in the Pt surface state and the kinetics of CO and Pt oxidation on Pt/CeO<sub>2</sub> during the CO oxidation reaction.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 8","pages":"Pages 2544-2550"},"PeriodicalIF":4.2000,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catalysis Science & Technology","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/org/science/article/pii/S2044475325001200","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The dynamics of CeO2-supported 1.5 nm Pt nanoparticles (Pt/CeO2) during catalysis for CO oxidation at 50 °C were observed. High-energy resolution fluorescence-detected (HERFD) Pt L3-edge X-ray absorption near-edge structure (XANES) spectroscopy with millisecond time resolution was used for this observation. A series of time-resolved spectra of Pt/CeO2 during CO oxidation were fitted by linear combinations of spectra corresponding to bare, CO-adsorbed, and surface-oxidised Pt nanoparticles. The analysis revealed that after O2 pulse injection into CO-adsorbed Pt nanoparticles, all adsorbed CO was oxidised within 0.5 s, forming a bare Pt surface. Subsequently, the bare Pt surface was oxidised at a much slower rate, approximately 10 s, compared with the oxidation of adsorbed CO. These findings demonstrate the utility of time-resolved HERFD-XANES spectroscopy in studying catalytic processes. This reveals variations in the Pt surface state and the kinetics of CO and Pt oxidation on Pt/CeO2 during the CO oxidation reaction.
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