Synthesis And Characterisation Of Halloysite Nanotubes Supported Nickel Catalysts For Hydrogenation Of Benzene
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Date
2017-06
Authors
Yusli, Farhana
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Two series of halloysite nanotubes supported nickel catalysts (Ni-HNT) were
prepared using classical and non-classical methods via impregnation technique. The
Ni content was varied between 2-14 wt% in both series of Ni-HNT catalysts.
Catalysts were characterized via Atomic Absorption Spectroscopy (AAS), Scanning
Electron Microscope (SEM), N2-adsorption desorption analysis, X-ray Diffraction
(XRD), High Resolution Transmission Electron Microscope (HRTEM), Hydrogen
Temperature-Programmed Desorption (H2-TPD), Hydrogen Chemisorption and
Hydrogen Temperature-Programmed Reduction (H2-TPR) techniques. The SEM
analysis showed that Ni particles were scattered depending on the different wt% of
Ni regardless of the preparation methods. XRD results reveal the presence of NiO
particles for the catalysts prepared via classical technique and the presence of Ni
metal particles for the non-classical technique. The SEM analysis showed that the Ni
species were deposited in the lumen of HNT as well as on its surface. The H2-TPD
and H2 chemisorption analyses suggested that different active sites and Ni particle
sizes may affect the desorption and adsorption of H2 respectively. Besides, the H2-
TPR analysis indicates the different strength of interaction of the Ni-HNT catalysts
as well as the availability of unreduced Ni species. For the classical catalysts, it was
found that the 9.3 wt% Ni-HNT/C showed the best conversion of benzene to
cyclohexane throughout the temperature range studied. This is due to the good
dispersion and less agglomeration of the Ni particles as confirmed by SEM and XRD
results.
Description
Keywords
Characterisation of halloysite nanotubes , hydrogenation of benzene