甲苯选择性氧化制备苯甲醛多相光催化剂研究进展

Progress on Heterogeneous Photocatalysts for Selective Oxidation of Toluene into Benzaldehyde

苯甲醛作为重要精细化学品,广泛地应用于医药(如合成头孢菌素)、香精香料、农药和染料等领域。由于光催化甲苯选择性氧化制苯甲醛具有反应条件温和、成本低和绿色环保等优势,其受到了研究者的关注。然而光催化甲苯选择性氧化催化剂存在高活性与高选择性不能兼得等问题,限制其实际应用。本文结合目前光催化甲苯选择性氧化可能机理,分别从强化载流子的分离、甲苯分子的吸附、活性物种的产生等方面对多相光催化甲苯选择性氧化的最新研究进展进行总结。同时,从光催化机理的深入研究、高效光催化剂的理性设计、光催化甲苯与其它小分子氧化偶联制备高附加值化学品新工艺以及光催化反应过程的放大个角度对光催化甲苯选择性氧化领域进行了展望。

As an important fine chemical,benzaldehyde is widely used in medicine(such as synthetic cephalosporins),flavors and fragrances,pesticides,dyes,and other fields.Due to the advantages of mild reaction conditions,low cost,and environmental protection,the strategy of photocatalytic selective oxidation of toluene to benzaldehyde has attracted much attention from scientists.However,the photocatalytic toluene selective oxidation suffered from shortcomings to achieve a high toluene conversion rate and benzaldehyde selectivity,which limits its practical application.In this review,the latest research progress on developing efficient photocatalysts by means of enhancing carrier separation,toluene molecule adsorption,and generation of active species was summarized based on the possible reaction mechanism.At the end of this review,we give a short prospect from the following aspects:an in-depth study of photocatalytic mechanism,rational design of high-efficiency photocatalysts,design of novel processes to realize the oxidative coupling reaction between toluene and other small molecular to produce value-added organics and design of an efficient photocatalytic reactor to amplify the reaction processes.