Sugunan, S; Suja, H; Deepa, C S; Sreeja Rani, K; Ouseph, M V(Indian Journal of Chemistry, November , 2002)
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Abstract:
Surface acidity of phosphate modified La2O3,CeO2 and SnO2 has been estimated by titrimetric Method using Hammett Indicators.Mixed Oxides of tin and lanthanum have also been prepared and subjected to phosphate modification.Surface characterizartion of the samples has been carried out using XRD, surface area,thermal analysis and IR spectroscopy.
Phosphate content in the samples has been chemically estimated. The catalytic activity for benzylation and esterification reaction has also been investigated.
Sugunan, S; Renuka, N K(Indian Journal of Chemistry, February , 2001)
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Abstract:
Vapour phase methylation of phenol is carried out over La2O3 supported vanadia systems of various composition. The structural features and physico chemical characterisation of the catalysts are investigated. Orthovanadates are formed in addition to surface vanadyl species on the metal oxide support. No V2O5 crystallites are detected. The acid base properties of the oxides are studied by Hammett indicator method and decomposition of cyclohexanol.The data are correlated with the catalytic activity and selectivity of the products. Ring alkylation is found to be predominant over these catalysts.
Iron and mixed iron aluminium pillared montrnorillonites prepared by partial hydrolysis method were subjected to room temperature
exchange with transition metals of the first series. The resulting materials were characterised by different spectroscopic techniques
and surface area measurements. About 1-3% transition metals were incorporated into the porous network. The structural
stability of the porous network was not affected by exchange. XRD and AI NMR spectroscopy evidenced the presence of iron
substituted Al13 like polymers in FeAl pillared systems. Acidity and basicity benefited much as a result of metal exchange. Acidity
and basicity were quantified by model reactions, viz., cumene cracking and cyclohexanol decomposition respectively. The presence
of basic sites in otherwise acidic pillared clays, though diminutive in amount can be of much importance in acid base catalysed
reactions.