二维金属-有机框架材料的制备、表征及其在异相催化中的应用进展

金属-有机框架纳米片(Metal-organic framework nanosheets, MONs)是近年来受到广泛关注的一类二维多孔材料,具有超薄厚度、比表面积大、结构可调节及大量可接触的不饱和配位点等优点,被应用于分离、导电、传感、催化等诸多领域中.综述了近年来国内外在MONs的制备、表征及其异相催化相关研究进展.MONs的制备包括"自上而下"和"自下而上"两种策略,自上而下策略操作简单,主要是通过物理化学手段将块状MOFs剥离成MONs;自下而上策略适用范围广,可通过控制实验条件合成MONs.另外,从结构组成、微观形貌、宏观性质等方面对MONs的表征方法和技术进行了讨论.介绍了MONs异相催化主要在有机转化中的应用,包括催化氧化反应、Knoevenagel反应、CO₂环加成反应及氢化反应等.最后指出了MONs研究所面临的机遇和挑战.

Preparation and Characterization of Two-Dimensional Metal-Organic Framework Nanosheets,and Their Application Progress in Heterogeneous Catalysis

Two-dimensional metal-organic framework nanosheets(MONs)are a type of 2 D porous materials that have received extensive attention in recent years. With ultra-thin thickness, abundant accessible unsaturated coordination sites,large specific surface area,advantages of adjustable structure,etc.,MONs are widely applied in many fields such as separation,conduction,sensing,and catalysis. This article mainly reviews the preparation,characterization and application in heterogeneous catalysis of MONs in recent years.The preparation of MONs includes two strategies,namely top-down and bottom-up. The top-down strategy is simple to operate,mainly involves exfoliation of layered bulk MOFs through physical or chemical means to into MONs. The bottom-up strategy involves direct assembly of 2 D MONs from metal ions and organic linkers under controlled experimental conditions. The characterization methods and techniques of MONs are discussed from the aspects of structure composition,microscopic morphology,and macroscopic properties.In addition,the application of MONs in heterogeneous catalysis,mainly organic conversion,is introduced,including catalytic oxidation reaction, Knoevenagel reaction, CO₂ cycloaddition reaction, hydrogenation reaction,etc. Finally,the opportunities and challenges in the field of MONs are pointed out.