Unlocking the scale-up of the benchmark MIL-53(Al) MOFs

Abstract Environment-friendly synthesis of metal-organic frameworks (MOFs) is crucial to meet growing industrial demand. Here, we present a generalized and scalable route for the production of the prototypical Al-OH chain-based microporous and flexible MIL-53 (MIL = Materials Institut Lavoisier) with various functional groups. Until recently, the scale-up of these robust and cost-effective Al-MOFs was hindered by challenges associated with their synthesis and purification, restricting their practical deployment. In this work, we optimized a reflux-based aqueous synthesis method and efficient unreacted linker removal process to yield either nano-sized or micron-sized particles. This approach affords high-purity MOFs and enables large-scale production with a high space-time yield (ca. 200 kg/m³/day), paving the way for broader implementation. As a proof of concept, we successfully produced MIL-53(Al)-NH 2 up to 300 g scale maintaining high quality and adsorption properties comparable to those achieved at smaller scale. Finally, shaping was performed using wet granulation method and the obtained spherical beads exhibited excellent mechanical strength and adsorption performances.