Sugunan, S; Bindhu, J; Disha; Jessey, V(Indian Journal of Chemistry, July , 1997)
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Abstract:
The Lewis acidity of yttrium and dysprosium exchanged
zeolite Y and ZSM-5 has been determined by titration method
using Hammett indicators. The acidity of the Y form increases
with increase in concentration of the rare earth cation in the Y
zeolite. It is independent of the amount of the rare earth ion for
ZSM-5. The data have been correlated with the activity of these
zeolites for the esterification of butanol using acetic acid.
Nishamol, K; Rahna, K S; Sugunan, S(Elsevier, 2004)
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Abstract:
Various compositions of chromium manganese ferrospinels were tested as catalysts for the vapour phase alkylation of aniline with methanol. The samples were prepared by room temperature co-precipitation technique and characterized by various physico-chemical methods. The acidity–basicity determination revealed that the samples possess greater amount of basic sites than acidic sites. All the ferrite samples proved to be selective and active for N-monoalkylation of aniline leading to N-methyl aniline; Cr0.6Mn0.4Fe2O4, Cr0.8Mn0.2Fe2O4 and CrFe2O4 exhibited cent percent selectivity for N-methyl aniline. Neither C-alkylated products nor any other side products were detected for all catalyst samples. The catalytic activity of the samples studied in this reaction is related to their acid–base properties and also on the cation distribution. Under the optimized reaction conditions all the systems showed constant activity for a long duration.