2D Metal–Organic Frameworks as Multifunctional Materials in Heterogeneous Catalysis and Electro/Photocatalysis

• Published in: Advanced materials (Weinheim) 2019-10, Vol.31 (41), p.e1900617-n/a
• Main Authors: Dhakshinamoorthy, Amarajothi, Asiri, Abdullah M., Garcia, Hermenegildo
• Format: Article
• Language: English
• Subjects: 2D materials; Catalysis; Catalysts; electrocatalysis; Electrocatalysts; heterogeneous catalysis; High aspect ratio; Metal-organic frameworks; Multifunctional materials; Photocatalysis; Thin films; Two dimensional materials
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201900617

Metal–organic frameworks (MOFs) are composed of particles with 3D geometry and are currently among the most widely studied heterogeneous catalysts. To further increase their activity, one of the recent trends is to develop related 2D materials with a high aspect ratio derived from a large lateral size and a small thickness. Here, the use of these 2D MOFs as catalysts, electrocatalysts, and photocatalysts is summarized, illustrating the advantages of these 2D materials compared to analogous 3D MOFs. The state of the art is summarized in tables and, when possible, pertinent turnover number (TON) and frequency (TOF) values. This enhanced activity of 2D MOFs derives from the accessibility of the active sites, the presence of a higher density of defects, and exchangeable coordination positions around the MOFs, as well as from their ability to form thin films on electrodes or surfaces. The importance of providing convincing evidence of the stability of 2D MOFs under reaction conditions and general characterization data of the used 2D material after catalysis is highlighted. In the last part, views regarding challenges in the field and new developments that can be expected are presented. 2D MOFs often exhibit higher catalytic activity compared to their respective 3D solids due to the absence of diffusion limitation to reach active sites, easy accessibility to active sites, and high population of active sites. The use of these 2D MOFs as catalysts, electrocatalysts, and photocatalysts is reviewed, illustrating their advantages compared to the analogous 3D MOFs.