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Abstract
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Over recent years, the group of scientists has exhibited a great interest in the design and deployment of chemicals and processes that pose a minimal threat to the environment. This urge stems from a critical need to mitigate pollution and reduce environmental risks associated with chemical processes. Consequently, technological advancements and scientific research are increasingly leaning towards adopting renewable resources and reusable catalysts1,2. Separation and recovery in homogeneous catalysis systems have historically been challenging processes. However, the advent of magnetic nanoparticles as catalysts heralds a significant shift in addressing these issues effectively. These nanoparticles offer many benefits including recyclability, and low reaction times owing to their super-paramagnetic behavior3,4. This method not only simplifies isolation but also augments the efficacy of the catalyst recovery process, which in turn enhances the purity of the end products5– 7. Therefore, magnetic separation occurs as an intriguing alternative to filtration or centrifugation, because it reduces loss of catalyst and makes the recovery and reusability of catalyst easier by magnetic force after the reaction8– 12. Polyoxometalates (POMs) are a class of solid acid catalysts that have garnered substantial attention due to their potential to serve as economically and environmentally friendly catalysts. Characterized by their unique structural and electronic properties, POMs have been instrumental in various fields including medicine, separation science, and catalysis. Furthermore, these compounds are known to be non-porous solid acids, possessing a low surface area which restricts their efficacy in catalytic processes. Moreover, their high solubility in water and various solvents poses a challenge in separating them from reaction products, often leading to significant losses during recycling processes13,14. To counter these drawbacks, researchers have embarked on strategies to enhance the stability of POMs. One effective approach has been the immobilization of POMs onto materials with high surface areas, which not only increases their efficacy but also facilitates easier separation from reaction mixtures, thus minimizing loss during recycling15. Several materials have been identified as suitable candidates for this process. These include active carbon16, chitosan17, GO18, MCM-4119, polymers20, and ZrO2 21.
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