Browsing by Author "Kim, T.H."

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Multi-walled carbon nanotube bound nickel Schiff-base complexes as reusable catalysts for oxidation of alcohols
(2012) Rajarao, R.; Kim, T.H.; Bhat, B.R.
Nickel salen and salophen complexes have been covalently anchored on multi-walled carbon nanotubes (MWNTs). The MWNT-supported nickel complexes have been characterized by inductive coupled plasma spectroscopy, FT-IR spectroscopy, UV-Vis spectrophotometry, transmission electron microscopy, and X-ray diffraction. The catalytic performance for the oxidation of primary and secondary alcohols was evaluated using periodic acid as oxidant. Reaction conditions have been optimized for MWNT-supported salen and salophen complexes by considering the effect of parameters such as solvent, reaction time, concentration of catalyst, amount of oxidant, etc. The catalytic activity was higher for supported catalysts than similar homogeneous ones. These supported catalysts were highly stable and reused several times without the loss of catalytic activity. 2012 Taylor & Francis.
Multi-walled carbon nanotube bound nickel Schiff-base complexes as reusable catalysts for oxidation of alcohols
(2012) Rajarao, R.; Kim, T.H.; Badekai Ramachandra, B.R.
Nickel salen and salophen complexes have been covalently anchored on multi-walled carbon nanotubes (MWNTs). The MWNT-supported nickel complexes have been characterized by inductive coupled plasma spectroscopy, FT-IR spectroscopy, UV-Vis spectrophotometry, transmission electron microscopy, and X-ray diffraction. The catalytic performance for the oxidation of primary and secondary alcohols was evaluated using periodic acid as oxidant. Reaction conditions have been optimized for MWNT-supported salen and salophen complexes by considering the effect of parameters such as solvent, reaction time, concentration of catalyst, amount of oxidant, etc. The catalytic activity was higher for supported catalysts than similar homogeneous ones. These supported catalysts were highly stable and reused several times without the loss of catalytic activity. © 2012 Taylor & Francis.
Selective oxidation of methanol to formaldehyde using modified iron-molybdate catalysts
(2004) Kim, T.H.; Ramachandra, B.; Choi, J.S.; Saidutta, M.B.; Choo, K.Y.; Song, S.-D.; Rhee, Y.-W.
Methanol selective oxidation to formaldehyde over a modified Fe-Mo catalyst with two different stoichiometric (Mo/Fe atomic ratio = 1.5 and 3.0) was studied experimentally in a fixed bed reactor over a wide range of reaction conditions. The physicochemical characterization of the prepared catalysts provides evidence that Fe2(MoO4)3 is in fact the active phase of the catalyst. The experimental results of conversion of methanol and selectivity towards formaldehyde for various residence times were studied. The results showed that as the residence time increases the yield of formaldehyde decreases. Selectivity of formaldehyde decreases with increase in residence time. This result is attributable to subsequent oxidation of formaldehyde to carbon monoxide due to longer residence time.