A Hollow Spherical Hydrotalcite-Based Catalyst for One-Step Ethoxylation of Butyl Acetate to Oligo-Ethylene Glycol Butyl Ether Acetates

Abstract

Abstract A novel hollow spherical hydrotalcite-based catalyst was developed for the direct ethoxylation of butyl acetate (BAC) to synthesize oligo-ethylene glycol butyl ether acetates (oligo-EBACs). This catalyst, which retains the intrinsic structural characteristics of hydrotalcite, was prepared via a secondary crystallization method. In comparison with conventional layered double hydroxide (LDH) materials, the as-synthesized catalyst achieves a higher conversion of BAC and a superior catalytic activity toward ethylene oxide (EO), along with a narrow adduct distribution of ethylene glycol butyl ether acetate (EBAC). When Cat-H as the catalyst, reaction temperature of 170 °C, reaction pressure of 0.4 MPa, and a molar ratio of n(BAC)/n(EO) = 4:1, the BAC conversion reached 26.2%, the EO catalytic activity was 0.248 g/(g·min), and the selectivities for 1-EBAC, 2-EBAC, and 3-EBAC were 44.39%, 26.14%, and 13.26%, respectively. After four consecutive recycling runs of the Cat-H, the conversion of BAC and the selectivities of other target products show a marginal decline.