Thermal Reduction of Cu2+ in presence of Ag+ in Clinoptilolite: Structural Study by EXAFS and HR-XRD

  • B. Concepción-Rosabal IMRE, Universidad de La Habana, La Habana, Cuba
  • I. Rodríguez-Iznaga IMRE, Universidad de La Habana, La Habana, Cuba
  • V. Petranovskii CNyN, Universidad Nacional Autónoma de México, Ciudad de México, México
  • F. Chavez-Rivas Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional (IPN), Ciudad de México, México
  • S. J.A. Figueroa Brazilian Synchrotron Light Laboratory (LNLS)/Brazilian Center of Energy and Materials (CNPEM), Campinas, Brazil
  • A. Pentón-Madrigal Facultad de Física- IMRE, Universidad de La Habana, La Habana, Cuba

Abstract

Extended X-ray absorption fine structure (EXAFS) and high resolution X-ray diffraction (XRD) experiments were carried out on Cu2+-Ag+ bimetallic system exchanged and then thermally reduced in natural clinoptilolite (CLI) from Tasajeras deposit (Cuba). The EXAFS signals of the bimetallic systems showed changes in the Cu2+ coordination as a result of their reduction at 150oC, which doesn't happen to CuCLI monometallic one. The presence of silver facilitates the reduction of Cu2+ in bimetallic systems forming only clusters. At higher reduction temperature (450oC) all mono- and bi-metallic samples exhibit mainly metallic particles of Cu and Ag with higher aggregation. These results are confirmed by XRD studies. Aggregation of reduced copper species is restricted in the presence of silver.

Published
Dec 14, 2019
How to Cite
CONCEPCIÓN-ROSABAL, B. et al. Thermal Reduction of Cu2+ in presence of Ag+ in Clinoptilolite: Structural Study by EXAFS and HR-XRD. Revista Cubana de Física, [S.l.], v. 36, n. 2, p. 119-124, dec. 2019. ISSN 2224-7939. Available at: <http://www.revistacubanadefisica.org/index.php/rcf/article/view/2019v36n2p119>. Date accessed: 29 may 2020.
Section
Original Articles