HIGHLIGHTS• The advantages of macroporous metal-organic frameworks (MOFs) in comparison with micro-and mesoporous MOFs are discussed.• A range of synthetic methods for the fabrication and characterisation of hierarchical MOFs with macroporosity are reviewed.• The applications, advancements, and challenges of each method are compared and assessed in detail.ABSTRACT Introduction of multiple pore size regimes into metalorganic frameworks (MOFs) to form hierarchical porous structures can lead to improved performance of the material in various applications.In many cases, where interactions with bulky molecules are involved, enlarging the pore size of typically microporous MOF adsorbents or MOF catalysts is crucial for enhancing both mass transfer and molecular accessibility. In this review, we examine the range of synthetic strategies which have been reported thus far to prepare hierarchical MOFs or MOF composites with added macroporosity. These fabrication techniques can be either pre-or post-synthetic and include using hard or soft structural template agents, defect formation, routes involving supercritical CO 2 , and 3D printing. We also discuss potential applications and some of the challenges involved with current techniques, which must be addressed if any of these approaches are to be taken forward for industrial applications.

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