Metal-organic frameworks: Synthetic methods for industrial production

Metal-organic frameworks (MOFs), which are constructed by metal ions or clusters with organic ligands, have shown great potential in gas storage and separation, luminescence, catalysis, drug delivery, sensing, and so on. More than 20,000 MOFs have been reported by adjusting the composition and reaction conditions, and most of them were synthesized by hydrothermal or solvothermal methods. The conventional solvothermal methods are favorable for the slow crystallization of MOFs to obtain single crystals or highly crystalline powders, which are suitable for the structure analysis. However, their harsh synthesis conditions, long reaction time, and difficulty in continuous synthesis limit their scale-up in industrial production and application. Meanwhile, shaping or processing is also required to bring MOF crystals and powders into the market. Therefore, this review demonstrates the crystallization mechanisms of MOFs to understand how the synthetic parameters affect the final products. Additionally, a variety of promising synthetic routes which can be used for large scale synthesis were reviewed in details. Lastly, the prospects of MOF shaping and processing are provided to promote their industrial application.