THERMAL REDUCTION OF Cu IN PRESENCE OF Ag IN CLINOPTILOLITE: STRUCTURAL STUDY BY EXAFS AND HR-XRD.
Cu-Ag bimetallic systems were exchanged and then thermally reduced in natural clinoptilolite (CLI) from Tasajeras deposit (Cuba). The systems were characterized by means of extended X-ray absorption fine structure (EXAFS) and high resolution X-ray diffraction (HR-XRD) experiments. The EXAFS signals...
| Publicado en: | Revista Cubana de Física Vol. 36; no. 2; pp. 119 - 125 |
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| Autores principales: | , , , , , |
| Formato: | Artículo |
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Universidad de La Habana
Dec2019
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=lth&AN=140834123&site=ehost-live header: @attributes: shortDbName: lth uiTerm: 140834123 longDbName: MedicLatina uiTag: AN controlInfo: bkinfo: jinfo: jid: 02539268 UEW jtl: Revista Cubana de Física issn: 02539268 maglogo: N pubinfo: dt: Dec2019 vid: 36 iid: 2 pid: 21208 pub: Universidad de La Habana artinfo: ui: 140834123 ppf: 119 ppct: 6 formats: fmt: @attributes: type: P size: 1.7MB tig: atl: THERMAL REDUCTION OF Cu IN PRESENCE OF Ag IN CLINOPTILOLITE: STRUCTURAL STUDY BY EXAFS AND HR-XRD. aug: au: CONCEPCIÓN-ROSABAL, B. RODRÍGUEZ-IZNAGA, I. PETRANOVSKII, V. CHÁVEZ-RIVAS, F. FIGUEROA, S. J. A. PENTÓN-MADRIGAL, A. affil: Instituto de Ciencia y Tecnología de Materiales (IMRE) - Universidad de La Habana, Cuba Facultad de Física- IMRE, Universidad de La Habana, La Habana, Cuba Centro de Nanociencias y Nanotecnología (CNyN) - Universidad Nacional Autónoma de México. Carretera Tijuana-Ensenada, Km 107. Ensenada, B.C. México Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional (IPN), C.P. 07738, México, D.F., México Brazilian Synchrotron Light Laboratory (LNLS)/Brazilian Center of Energy and Materials (CNPEM), CP 6192, 13083-970, Campinas, SP, Brazil su: Clinoptilolite Extended X-ray absorption fine structure Zeolite Y Agglomeration (Materials) X-ray diffraction Silver Copper compounds Cuba sug: subj: Cuba Clinoptilolite Extended X-ray absorption fine structure Zeolite Y Agglomeration (Materials) X-ray diffraction Silver Copper compounds ab: Cu-Ag bimetallic systems were exchanged and then thermally reduced in natural clinoptilolite (CLI) from Tasajeras deposit (Cuba). The systems were characterized by means of extended X-ray absorption fine structure (EXAFS) and high resolution X-ray diffraction (HR-XRD) experiments. The EXAFS signals of the bimetallic systems showed changes in the Cu coordination as a result of their reduction at 150℃, which doesn't happen to CuCLI monometallic one. The presence of silver facilitates the reduction of Cu in bimetallic systems forming only clusters. At higher reduction temperature (450℃) all mono- and bi-metallic samples exhibit mainly metallic particles of Cu and Ag with higher aggregation. These results are confirmed by HR-XRD studies. Aggregation of reduced copper species is restricted in the presence of silver. Sistemas bimetálicos de Cu-Ag intercambiados y seguidamente reducidos térmicamente en la clinoptilolita natural (CLI) del yacimiento de Tasajeras (Cuba) fueron objeto de experimentos de estructura fina de absorción extendida de rayos X (EXAFS, acrónimo en inglés) y difracción de rayos - X (XRD, acrónimo en inglés) de alta resolución. Las señales de EXAFS de los sistemas bimetálicos mostraron cambios en la coordinación del Cu como resultado de su reducción a 150℃, lo cual no sucede en el sistema monometálico de CuCLI. La presencia de la plata facilita la reducción del Cu en los sistemas bimetálicos, formándose solamente clústeres a esta temperatura. A mayor temperatura de reducción (450℃) todas las muestras mono- y bi-metálicas exhiben principalmente partículas de Cu y Ag metálico con mayor agregación. Estos resultados se confirman por estudios de XRD. La agregación de las especies de cobre reducidas es restringida en presencia de la plata. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y custom: Copyright of Revista Cubana de Física is the property of Universidad de La Habana and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. item: Revista Cubana de Física holder: Universidad de La Habana dt: @attributes: year: 2019 holdings: @attributes: islocal: N |
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