Effect of the ZrO2 Crystal Phase on Performance over a CuCeZrO Catalyst for Dehydrogenative Condensation of Ethanol to Ethyl Acetate.

Abstract

Ethyl acetate is an important chemical, and ethanol dehydrogenative condensation with 95.6% atomic economy is a promising synthetic route. CuZrO-based catalysts are widely applied in this reaction; however, the effect of the ZrO2 crystal phase in the CuCeZrO catalyst upon reaction deserves to be explored further. Herein, the ZrO2 crystal phase in the CuCeZrO catalyst was regulated by controlling the calcination temperature, and a high temperature (≥600 °C) is conducive to the transformation of the tetragonal phase to the monoclinic phase. Additionally, monoclinic ZrO2 (m-ZrO2) with limited density of the strong base is found to be more beneficial to the selective production of ethyl acetate from ethanol, while tetragonal ZrO2 (t-ZrO2) with abundant strongly basic sites is more inclined to the formation of butanol and its downstream esters. This work not only improves our understanding of the crystal phase effect in a CuCeZrO catalytic system but also paves the way for the development of more efficient catalysts for ethyl acetate production.