Deactivation aspect of BEA zeolite in microwave assisted synthesis of 2-cyclohexyl-4-methyl phenol by cyclohexylation of p-cresol

Autor: B. M. Chandra Shekara, B. S. Jai Prakash, Yajnavalkya S. Bhat
Rok vydání: 2012
Předmět:
Zdroj: Journal of Porous Materials. 20:827-837
ISSN: 1573-4854
1380-2224
DOI: 10.1007/s10934-012-9658-y
Popis: Selective synthesis of 2-cyclohexyl-4-methyl phenol (2-CH-4-MP) by liquid phase alkylation of p-cresol with cyclohexanol and cyclohexene over BEA zeolite has been investigated under microwave as well as conventional heating. Significant acceleration of reaction rate was observed under microwave heating. However, no difference in conversion or selectivity was noticed between the two modes of heating. Various reaction parameters like catalyst amount, mole ratio of reactants, temperature and reaction time showed a significant influence on the distribution of products. With cyclohexanol as alkylating agent, initially formed cyclohexene and O-alkylated product were converted to 2-CH-4-MP with increase in temperature, catalyst amount and reaction time. When cyclohexene is used directly as alkylating agent, C-/O-product ratio also increased with increase in temperature, catalyst amount and reaction time. However, in both the cases, selectivity to 2-CH-4-MP was almost same. Deactivation of BEA zeolite was observed during the reaction possibly due to coking constituents. In an attempt to stabilize the catalytic activity of BEA zeolite, it was dealuminated to different extents by treating with 0.1, 0.2 and 0.5 M solutions of p-toluene sulphonic acid. The catalytic activity and deactivation behaviour of dealuminated samples in the alkylation reaction were investigated.
Databáze: OpenAIRE
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