engineered magnetic nanoparticles as recyclable brønsted acid catalysts: advances in particle design and applications in organic transformations

The development of functionalized magnetic nanoparticles (mnps) as heterogeneous catalysts represents a significant advancement in sustainable chemical synthesis. among these, mnps functionalized with brønsted acid groups, particularly sulfonic acids, phosphonic acids, and acidic ionic liquids, have emerged as a versatile class of catalysts that combine the efficiency of homogeneous acids with the practical benefits of magnetic recoverability. these systems address critical challenges in traditional acid catalysis, including catalyst separation, waste generation, and energy-intensive recovery processes. by leveraging the unique properties of magnetic cores (e.g., fe3o4, cofe2o4) and tailored acid-functionalized shells, researchers have created robust catalytic platforms applicable to diverse organic transformations, from biomass valorization to pharmaceutical synthesis. this review aims to provide a comprehensive overview of recent developments in the synthesis, characterization, and catalytic applications of magnetic nanoparticles functionalized with brønsted acid groups.