Selectivity engineering in hydroxyalkoxylation of phenol by ethylene carbonate using calcined hydrotalcite

Abstract

The high consumption of mono-ethylene glycol phenyl ether in various sectors requires clean and green synthesis. Herein, we report an efficient, selective and green route of hydroxylation using calcined hydrotalcite (CHT) for the preparation of mono-ethylene glycol phenyl ether. Various types of solid base catalysts were prepared and well characterized by TGA–DSC, FTIR, XRD, CO₂-TPD, NH₃-TPD, SEM and BET surface area. The catalyst CHT (3:1) possesses very high activity for hydroxyalkoxylation of phenol and ethylene glycol with 96% conversion at 180 °C in 2 h with catalyst loading of 0.03 g cm⁻³. The insight of reaction reveals that it is kinetically controlled with second-order reaction and follows power law model. The apparent activation energy for the reaction is 21.3 kcal mol⁻¹. The catalyst is highly reusable and shows green chemistry prospective and gives excellent results up to four runs.