Catalytic decomposition of ethylene on nanocrystalline cobalt

Marcin Podsiadły ,  Urszula Narkiewicz ,  Walerian Arabczyk ,  Iwona Pełech 

Technical University of Szczecin, Institute of Chemical and Environment Engineering, Pulaskiego 10, Szczecin 70-322, Poland

Abstract

Nanocrystalline ferromagnetic metals (such as Fe, Co and Ni) have many applications in magnetic data storage, magnetic toners in xerography, magnetic inks and ferrofluids. However, nanocrystalline metals are very sensitive to rapid environmental degradation. This attribute significantly limits the scope of their potential industrial applications. Encapsulation of nanocrystals with graphitic layers is a way to protect metal crystals from negative environmental influence. Also, carbon coatings can endow these particles with biocompatibility and make carbon-encapsulated particles useful in bio-engineering applications, such as drug delivery, biosensors, magnetic hyperthermia and magnetic contrast agents for magnetic resonance imaging.

Carbon-coated cobalt nanoparticles were successfully synthesized by catalytic ethylene decomposition. Nanocrystalline cobalt was prepared by cobalt hydroxide precipitation, followed by calcination and reduction. A small amount of structural promoters was added. The process of cobalt oxide reduction and cobalt carburisation was carried out in a thermobalance. The carburisation process was performed under pure ethylene flow in the temperature range 340 - 400°C. After carburisation process the samples were cooled under helium flow or reduced under hydrogen flow in the temperature range 500 - 560°C. The phase composition of the samples was determined using XRD technique. The phases in carbon-coated nanocapsules turned out to be fcc-Co and hcp-Co. The HRTEM method was used to study the morphology of the samples after carburisation. Both carbon-coated cobalt nanocapsules and carbon nanotubes were found in the samples.

The financial support of the Scientific Network "Nanomaterials as Catalysts for New, Environmentally Friendly Processes" for the participation of the corresponding author in the EMRS Fall Meeting'06 is gratefully acknowledged.

 

Related papers
  1. Welcome address
  2. Carbon nanotubes applications for drug and gene delivery
  3. Europejska Platforma Technologiczna Nanomedycyny
  4. ZrO2:Tb nanopowders obtained by coprecipitation method
  5. ZnFe2O4/ZnO core-shell particles obtained by coprecipitation route
  6. Raman scattering from ZnO doped with Fe, Mn and Co nanoparticles
  7. Hydrothermal Synthesis of ZnAl2O4 Spinel
  8. Comparison of Au/ZrO2 materials prepared by precipitation and impregnation methods
  9. Low-frequency Raman scattering from transition-metal-doped ZnO nanoparticles
  10. Surface chemistry of Pr-doped nanocrystalline zirconia
  11. Kinetics of the formation of nanocrystalline magnetite in a carbon matrix
  12. Effect of iron addition on the properties of ZnO obtained by precipitation
  13. Iron-carbon nanofillers for polymers
  14. Poisoning of iron catalyst with sulfur
  15. FMR study of carbon coated cobalt nanoparticles dispersed in paraffin
  16. Temperature dependence of the FMR spectra of polymer composites with nanocrystalline α-Fe/C filler
  17. Ferromagnetic resonance from nanoparticle agglomerates in nonmagnetic matrices
  18. Magnetic resonance study of PTMO - block - PET copolymer filled with a mixture of Fe3O4 and Fe3C nanoparticles at low concentration
  19. Surface diffusion of potassium from iron catalyst
  20. Studies of the initial stage of the carburisation of nanocrystalline iron with methane
  21. KINETICS OF CARBON DEPOSIT FORMATION FROM DECOMPOSITION OF METHANE ON NANOCRYSTALLNE IRON SURFACE
  22. Temperature dependence of microwave resonance absorption studies of α-iron and iron carbide nanoparticle agglomerates in a diamagnetic matrix
  23. Nanocrystallline iron-carbon fillers for polymers
  24. Preparation of the Nanocrystalline Iron Carbide in Reaction of Iron with Methane or Methane/Hydrogen Mixture

Presentation: Poster at E-MRS Fall Meeting 2006, Symposium B, by Iwona Pełech
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-02-01 12:33
Revised:   2009-06-07 00:44