Modification of surface activity of Cu-based amorphous alloys by chemical processes of metal degradation

M. Janik-Czachor, A. Szummer, J. Bukowska, A. Molnar, P. Mack, S. M. Filipek, P. Kedzierzawski, A. Kudelski, M. Pisarek, M. Dolata, M. Varga

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Changes in morphology, local chemical composition, catalytic activity and local surface-enhanced Raman scattering (SERS) activity due to various methods of modification of surfaces of Cu-Zr, Cu-Hf and Cu-Ti amorphous alloys were investigated. Our recent investigations have shown that otherwise detrimental processes of material degradation may help to segregate clusters of Cu and to develop a large specific surface area of Cu on ZrOx or HfOx supports. This transforms the original Cu-based amorphous ribbons of low surface area into efficient and stable catalysts. The following methods of activation based on the degradation processes, and their combinations are presented: ageing/oxidation in air, anodic activation, and pre-treatment with hydrogen (hydrogenation under high hydrogen pressure, or cathodic hydrogen charging). Structural changes in the bulk of the amorphous alloys introduced by the above pre-treatments were examined by XRD. Morphological and chemical changes on the surface were followed microscopically (optical microscopy and high resolution SEM) and by using a high resolution scanning Auger microprobe (SAM) and an X-ray electron microprobe. The amount of segregated Cu on the surface was estimated by an electrochemical method. A test reaction of dehydrogenation of 2-propanol was used to compare the catalytic activity of the materials after different chemical pre-treatments. Proposed mechanisms of changes in the local adsorption properties, local enhancement of Raman spectra and the catalytic activities due to the above combined pre-treatments are discussed.

Original languageEnglish
Pages (from-to)157-170
Number of pages14
JournalApplied Catalysis A: General
Volume235
Issue number1-2
DOIs
Publication statusPublished - Aug 30 2002

Fingerprint

Amorphous alloys
Metals
Degradation
Hydrogen
Catalyst activity
Raman scattering
Chemical activation
2-Propanol
Propanol
Dehydrogenation
Specific surface area
Hydrogenation
Optical microscopy
Aging of materials
Scanning
Adsorption
X rays
Oxidation
Scanning electron microscopy
Catalysts

Keywords

  • Cu-based catalysts
  • Dehydrogenation of alcohols
  • Devitrification
  • SEM/SAM investigations
  • Surface analysis
  • Surface-enhanced Raman scattering

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

Modification of surface activity of Cu-based amorphous alloys by chemical processes of metal degradation. / Janik-Czachor, M.; Szummer, A.; Bukowska, J.; Molnar, A.; Mack, P.; Filipek, S. M.; Kedzierzawski, P.; Kudelski, A.; Pisarek, M.; Dolata, M.; Varga, M.

In: Applied Catalysis A: General, Vol. 235, No. 1-2, 30.08.2002, p. 157-170.

Research output: Contribution to journalArticle

Janik-Czachor, M, Szummer, A, Bukowska, J, Molnar, A, Mack, P, Filipek, SM, Kedzierzawski, P, Kudelski, A, Pisarek, M, Dolata, M & Varga, M 2002, 'Modification of surface activity of Cu-based amorphous alloys by chemical processes of metal degradation', Applied Catalysis A: General, vol. 235, no. 1-2, pp. 157-170. https://doi.org/10.1016/S0926-860X(02)00260-0
Janik-Czachor, M. ; Szummer, A. ; Bukowska, J. ; Molnar, A. ; Mack, P. ; Filipek, S. M. ; Kedzierzawski, P. ; Kudelski, A. ; Pisarek, M. ; Dolata, M. ; Varga, M. / Modification of surface activity of Cu-based amorphous alloys by chemical processes of metal degradation. In: Applied Catalysis A: General. 2002 ; Vol. 235, No. 1-2. pp. 157-170.
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