Microenvironment Modulation in Metal–Organic Framework-Based Catalysis

ConspectusThe fine design and regulation of catalysts play critical roles in the development of catalysis. The microenvironment, which gives rise to unique spatial structures and electronic properties around catalytic sites, has been proven to dramatically regulate catalytic behavior in enzymes and homogeneous catalysis. However, understanding the microenvironment modulation (MEM) of catalytic sites remains challenging and very limited in heterogeneous catalysis mainly due to the lack of structural precision and/or tailorability of traditional solid catalysts. Among diverse materials, metal–organic frameworks (MOFs), a class of porous crystalline solids, have been intensively studied as heterogeneous catalysts in recent years. The atomically precise and well tunable structures of MOFs make them an ideal platform for rationally regulating the microenvironment surrounding catalytic sites. Accordingly, their well-defined structures hold great promise for elucidating how the microenvironment modulation affects the resulting catalytic performance. Nevertheless, the investigations of accurate control over the microenvironment of catalytic sites in MOFs for modulated catalysis are still very limited. Therefore, it is of great importance to summarize the related results and provide in-depth insights into microenvironment modulation in MOF-based catalysis, accelerating the future development of this emerging research topic.In this Account, we have presented a summary of our recent attempts to optimize the catalytic performance of MOF-based materials via microenvironment modulation. In view of the unique component and structural advantages of MOFs, we deliver the general fundamentals for rational control over the microenvironment in MOF-based catalysis. Initially, the great opportunities brought about by MOFs for accurate control over microenvironment engineering, including the origin of abundant active sites, flexible regulation strategies, and well-defined structure, are introduced in detail. In the next section, we focus on the specific strategies of microenvironment modulation in MOF-based catalysis, which dominate the molecular/electron-transfer process and regulate the intrinsic activity of catalytic sites. Meanwhile, the related chemical basis and underlying structure–property relationship behind the enhanced catalytic performance will be highlighted. Finally, the major challenges and future outlooks on the microenvironment modulation in MOF-based catalysis will be further discussed. It is expected that this Account would provide an understanding of the importance of microenvironment modulation around catalytic sites in MOF-based catalysts and afford significant inspiration toward enhanced performance by microenvironment engineering in heterogeneous catalysis.