氧化酯化反应催化剂的研究进展

Research progress on oxidative esterification catalysts

本工作综述了近年来醛或醇氧化酯化催化剂的研究进展,介绍了均相催化剂和非均相催化剂的研究情况,其中均相反应体系,催化剂不易分离且能耗较大,价格普遍偏高,适用于氧化酯化的均相反应体系难以工业化。非均相反应体系在工业化方面具有很大优势,催化剂分离简单易还原、可回收再利用等,但同样存在稳定性较差及收率较低的问题。分析了贵金属催化剂和非贵金属催化剂的合成、结构及催化醛氧化酯化性能,总结了部分催化剂催化醛氧化酯化的反应机理。通过各种制备方法调控催化剂的结构、形貌、比表面积,进而暴露大面积活性面及延长催化剂的使用寿命来提高催化剂的经济效益。展望了氧化酯化反应催化剂的研究方向,贵金属催化剂由于成本限制,非贵金属催化剂将是未来醛氧化酯化领域重点研究的方向。要点:(1)综述了醛与醇一步氧化酯化催化剂的研究进展。(2)重点介绍了均相催化剂与非均相催化剂的研究情况。(3)展望了氧化酯化反应催化剂的研究方向。

Ester is an important chemical intermediate, which is usually oxidized by aldehyde or alcohol to prepare acids or derivatives of acids, and ester is prepared by esterification, but the conventional process is complicated, and the energy consumption is very high. How to produce esters efficiently and clean is a common problem to be solved urgently in the industrial synthesis of ester. One-step oxidative esterification of aldehydes with alcohols to esters is a simple, clean and efficient green synthesis method. The activity and lifetime of catalysts are particularly important in this process, which mainly depends on the design and preparation of catalysts. In this work, the recent development of catalysts for oxidative esterification of aldehydes was reviewed. Homogeneous catalysts and heterogeneous catalysts were mainly introduced. In the homogeneous reaction system, the catalyst was not easy to be separated, the price was generally high and had large energy consumption. Therefore, the homogeneous reaction system which was suitable for oxidative esterification was difficult to be industrialized. However, the heterogeneous reaction system had great advantages in industrialization. The catalyst was simple to separate and easily degradable, and can be recycled and reused, but also had problems such as poor stability and low yield. The synthesis, structure and catalytic performance of noble metal catalysts and non-noble metal catalysts for oxidative esterification of aldehydes were analyzed and the reaction mechanism of partial catalysts was summarized. The structure, morphology and specific surface area of the catalysts were adjusted by various preparation methods to expose a large area of the active surface, prolong the service life of the catalyst, and improve the economic efficiency of the catalysts. In addition, the research direction of catalysts for oxidative esterification was prospected. Noble metal catalysts were limited in terms by the cost, no-noble metal catalysts will be the focus of future research for the oxidative esterification of aldehyde with alcohols. Key learning points:(1) Research progress on catalysts of one-step oxidative esterification of aldehydes with alcohols to esters.(2) The research situation of homogeneous catalysts and heterogeneous catalysts was mainly introduced.(3) Research direction of catalysts for oxidative esterification was prospected.