Sugunan, S; Seena, C R K(Indian Journal of Chemistry, September , 1999)
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Abstract:
The surface acidity/ basicity of TiO2 (rutile) and its sulphate modified
form have been determined by titration method using Hammett
indicators after activation at different temperatures. The electron
donating properties of these oxides are also studied from the adsorption
of electron acceptors of different electron affinity values. The
data have been correlated with the catalytic activity of these oxides
towards esterification of acetic acid using n-butanol, reduction of
cyclohexanone in isopropanol and oxidation of cyclohexanol in benzophenone.
Catalytic activity for esterification and oxidation reaction
parallels the acidity while that for reduction reaction parallels
the basicity of these oxides.
Sugunan, S; Seena, Kumaree C R(Indian Journal of Chemistry, November , 1999)
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Abstract:
The changes in surface acidity/basicity and catalytic activity of cerium oxide due to surface modification by sulphate ion have been
investigated. Electron donor properties of both the modified and unmodified oxides have been studied using electron acceptors of
various electron affinity values, viz. 7,7,8,8-tetracyanoquinodimethane, 2,3,5,6-tetrachloro--l, 4-benzoquinone. p-dinitrobenzene and
m-dinitrobenzene in order to find out whether the increase in acidity on suphation is due to the generation of new acidic sites or they are
formed at the expense of some of the basic sites. The surface acidity/basicity has been determined using a set of Hammett indicators.
The data have been correlated with the catalytic activity of the oxides for esterification of acetic acid using l-butanol, reduction of
cyclohexanone with 2- propanol and oxidation of cyclohexanol using benzophenone.
Sugunan, S; Sherly, K B; Devika Rani, G(React. Kinet.Catal.Lett., 1993)
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Abstract:
The limit of electron transfer in electron affinity from
the oxide surface to the electron acceptor (EA) are reported
from the adsorption of EA on DY203, mixed oxides
of DY203 with alumina and mixed oxides of Y203 with y-alumina.
The extent of electron transfer is understood
from magnetic measurements.