Recyclable CuMgAl hydrotalcite for oxidative esterification of aldehydes with alkylbenzenes

Abstract

A series of hydrotalcite-like compounds with various Cu:Mg:Al molar ratios were prepared by the coprecipitation method. The catalytic performance for oxidative esterification of aldehydes was investigated. X-ray diffraction, N2 adsorption–desorption (BET), hydrogen temperatureprogrammed reduction (H2-TPR), X-ray photoelectron spectroscopy, the scanning electron microscope (SEM), the transmission electron microscope and atomic absorption spectrometry were used to characterize the catalysts. The results showed that the benzyl benzoate product was obtained in good to excellent yield using tert-butyl peroxybenzoate as oxidant at 90°C under air atmosphere over Cu2Mg1Al1-LDH catalyst. The catalyst can be recovered and used with 45% conversion after recycling five times. The oxidative esterification reaction in the heterogeneous system is environmentally friendly.