A critical review on recent trends in metal-organic framework-based composites as sustainable catalysts for environmental applications

There is a growing demand for environmental sustainability mainly due to the increased industrialization leading to the emissions of harmful substances and other contaminations that affect the planet's ecological balance. One of the promising approaches is via catalytically converting such contaminants and pollutants to less harmful or valuable products using metal organic frameworks (MOFs). These are group of materials which are porous, crystalline and are formed via strong coordination bonds between organic ligands and inorganic metal ions/clusters, thereby resulting to a periodic network structure. They possess unique properties including large surface area, open metal sites, multi-functionalization and changeable structures. Notably, MOFs can be combined with nanomaterials, polyoxometalates (POMs) and derived porous carbon materials to form synergistic MOF-based composites with intrinsic properties of both the MOFs and the composite material. Hence, this review focuses on the emerging and sustainable catalytic applications of MOF-based composites. Additionally, detailed reaction mechanisms of MOF-based composites considering both kinetic and thermodynamic implications, have been elaborated. Finally, discussions centered around the challenges limiting the utilization of MOF-based composites and future research directions, have been provided. This review promises to be useful for researchers and professionals interested in promoting environmental sustainability and sustainable development goals (SDGs) using MOF-based catalysts.