Catalytic tertiary butylation of phenol over sulfonated mesoporous polymer catalyst (MP-SO3H): Exceptional selectivity towards 2,4-di-t-Butylphenol

摘要

The alkylation of phenol with alcohols/olefins is an important reaction to transform lignin based phenolics to useful chemicals. In the present study, the sulfonated mesoporous polymers exemplified the exceptional selectivity towards 2,4-DTBP. This remarkable activity of the material is well correlated with its textural properties. The characterization data reveals that the presence of intrinsic mesoporosity, high acid strength, uniform distribution of acidic sites over high surface area are the prerequisites to facilitate this unusual selectivity to 2,4-DTBP. The various micro and mesoporous catalysts have been screened to compare the catalytic activity of MP-SO3H. The MP-SO3H-8 surpassed the catalytic activity of all the catalysts screened. The MP-SO3H-8 exhibits 99.5% phenol conversion and 78% selectivity to 2,4-DTBP. To the best of our knowledge, this is the highest yield ever achieved to 2,4-DTBP till date. In addition, leaching & recyclability studies prove that the material is stable to retain its catalytic activity up to three recycles.