Chemicals from ethanol: the acetone synthesis from ethanol employing Ce _0.75Zr _0.25O ₂, ZrO ₂ and Cu/ZnO/Al ₂O ₃

Abstract

Acetone is an important solvent and widely used in the synthesis of drugs and polymers. Currently, acetone is mainly generated by the Cumene Process, which employs benzene and propylene as fossil raw materials. Phenol is a co-product of this synthesis. However, this ketone can be generated from ethanol (a renewable feedstock) in one-step. The aim of this work is to describe the influence of physical–chemical properties of three different catalysts on each step of this reaction. Furthermore, contribute to improve the description of the mechanism of this synthesis. The acetone synthesis from ethanol was studied employing Cu/ZnO/Al ₂O ₃, Ce _0.75Zr _0.25O ₂ and ZrO ₂. It was verified that the acidity of the catalysts needs fine-tuning in order to promote the oxygenate species adsorption and avoid the dehydration of ethanol. The higher the reducibility and the H ₂O dissociation activity of the catalysts are, the higher the selectivity to acetone is. In relation to the oxides, these properties are associated with the presence of O vacancies. The H ₂ generation, which occurs during the TPSR, indicates the redox character of this synthesis. The main steps of the acetone synthesis from ethanol are the generation of acetaldehyde, the oxidation of this aldehyde to acetate species (which reduces the catalyst), the H ₂O dissociation, the oxidation of the catalyst producing H ₂, and, finally, the ketonization reaction. These pieces of information will support the development of active catalysts for not only the acetone synthesis from ethanol, but also the isobutene and propylene syntheses in which this ketone is an intermediate.

Graphical abstract

Acetone from ethanol.

Electronic supplementary material

The online version of this article (doi:10.1186/s13065-017-0249-5) contains supplementary material, which is available to authorized users.