Rodrigues Clarissa Perdomo, Zonetti Priscila da Costa, Appel Lucia Gorenstin
Divisão de Catálise e Processos Químicos, Instituto Nacional de Tecnologia, Av. Venezuela 82/518, Saúde, Rio de Janeiro, RJ, CEP 21081-312, Brazil.
Chem Cent J. 2017 Apr 4;11(1):30. doi: 10.1186/s13065-017-0249-5.
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/AlO, CeZrO and ZrO. 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 HO 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 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 HO dissociation, the oxidation of the catalyst producing H, 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.
丙酮是一种重要的溶剂,广泛应用于药物和聚合物的合成。目前,丙酮主要通过异丙苯法生产,该方法使用苯和丙烯作为化石原料。苯酚是这种合成方法的副产物。然而,这种酮可以由乙醇(一种可再生原料)一步生成。这项工作的目的是描述三种不同催化剂的物理化学性质对该反应各步骤的影响。此外,有助于改进对这种合成机理的描述。采用Cu/ZnO/AlO、CeZrO和ZrO研究了由乙醇合成丙酮的过程。结果表明,为了促进含氧化合物的吸附并避免乙醇脱水,需要对催化剂的酸度进行微调。催化剂的还原性和H₂O解离活性越高,丙酮的选择性就越高。对于氧化物而言,这些性质与氧空位的存在有关。在程序升温表面反应(TPSR)过程中产生的H₂表明了这种合成的氧化还原特性。由乙醇合成丙酮的主要步骤包括乙醛的生成、该醛氧化为乙酸盐物种(这会使催化剂还原)、H₂O解离、催化剂氧化生成H₂,最后是酮化反应。这些信息将不仅支持开发用于由乙醇合成丙酮的活性催化剂,还支持开发用于异丁烯和丙烯合成的活性催化剂,在这些合成中丙酮是中间体。图形摘要:由乙醇合成丙酮