金属有机骨架基绿色催化剂在醇氧化反应中的研究应用

Metal‐organic‐framework‐based materials as green catalysts for alcohol oxidation

醇的选择性氧化是一类非常重要的有机合成反应,因其能够生产多种高值化学品和重要的化工原料,被广泛应用于全合成、精细化工与医药等领域.目前虽已开发出多种可将醇转化为醛、酮或酸等产物的催化体系,但仍普遍存在反应条件苛刻、转化率低和选择性差等问题,且大多数催化氧化体系还涉及使用危险性氧化剂、添加剂或有毒试剂,导致产生大量有害废弃物和造成环境污染,因此开发高效、安全且环境友好的用于醇氧化绿色催化剂具有重要意义.金属有机骨架(MOFs)是一类由有机配体和金属离子/团簇组装而成的具有重复网络结构的多孔晶体材料,具有比表面积大、孔结构可调、活性位点丰富以及易于回收再利用等优点,在醇类绿色催化氧化领域中表现出巨大潜力,受到了研究者的广泛关注.MOFs还可作为载体与其它催化活性组分进行复合构筑MOFs基复合材料,或作为前驱体通过热处理等手段获得多种MOFs衍生物材料,这两类MOFs基材料在保留MOFs材料高比表面积、大孔隙率等特征的基础上,进一步集成了多元活性位点和良好结构稳定性等优势.本综述总结和讨论了近年来MOFs基材料作为绿色催化剂在醇催化氧化领域的代表性研究进展.按照MOFs基材料种类(纯MOFs、MOFs复合材料和MOFs衍生物)和反应类型(热催化、光催化和电催化)进行系统分类,并依据MOFs基材料属性(MOFs金属节点种类、MOFs基复合材料负载活性组分种类、MOFs衍生物金属中心种类以及光催化改性策略种类)对各章节内容进行了分类介绍,同时围绕材料基本合成工艺、催化反应条件及催化性能、底物普适性、醇氧化机理和材料稳定性等方面对多种所涉及的MOFs基材料进行了详细介绍,并从计算角度出发介绍了密度泛函理论(DFT)在MOFs基材料催化醇类氧化方面的应用.此外,还充分讨论了MOFs基材料作为醇氧化用绿色催化剂的基本特征、设计原则、合成策略和催化机制,并针对潜在的科学挑战提出了相应的解决方案.本文旨在介绍当前醇类氧化用MOFs基绿色催化剂及催化体系的研究现状,为高效、绿色、安全、稳定的催化新体系开发提供设计思路和理论依据,进一步推动MOFs基催化剂在醇氧化领域的规模化推广与应用.总体而言,虽然目前MOFs基材料在稳定性、规模化生产等方面仍面临诸多挑战,但随着研究的进一步深入, MOFs基催化剂在醇类绿色催化氧化领域将展现出更广阔的应用前景.

The selective oxidation of alcohols is widely regarded as one of the most important reactions inorganic synthesis. Although efficient and environmentally friendly catalysts for alcohol oxidationare highly desirable, their development remains an enormous challenge. Metal‐organic framework(MOF)‐based catalysts have demonstrated great potential in the catalytic oxidation of alcohols andhave remarkably progressed in the past few decades owing to their advantages of large surfacearea, tunable porous structure, abundant accessible active sites, and ease of reuse and recycling. Inthis review, recent representative results of the catalytic oxidation of alcohols by MOF‐based materialsare summarized and classified according to the type of material and reaction, such as pristineMOFs, MOF composites, and MOF derivatives for traditional thermal catalysis, photo‐assisted catalysis,and electro‐assisted catalysis. Each catalytic system is described in detail from multiple aspects,including the materials synthesis process, catalytic performance, alcohol oxidation mechanisms,and material stability. Thus, the aims of this review are to identify potentially efficient, green,and reusable MOF‐based catalytic systems and to provide new insights for the further developmentof catalytic alcohol oxidation to obtain the target organics.