Polyol-Assisted Palladium Nanoparticle Synthesis and Its Application in Hydrogenation Reaction: A Mini Review

The polyol process, developed over the past four decades, has emerged as a versatile soft chemical route for the synthesis of metal nanoparticles with broad technological relevance. It offers several advantages, including low cost, operational simplicity, and proven scalability for industrial application. Among its key uses, polyol-assisted nanoparticles play a critical role in selective catalytic hydrogenation in the petrochemical and fine chemical industries. Nevertheless, synthesis becomes more challenging when substrates possess multiple functional groups, requiring high selectivity. In this context, palladium nanoparticles prepared via the polyol method have demonstrated notable efficiency in hydrogenation reactions. This review highlights the polyol-mediated synthesis of Pd nanoparticles, considering first-row transition metals to provide a broader perspective. In particular, biphasic systems that enable efficient phase separation and recovery have been broadly demonstrated. Overall, this review emphasizes the potential of polyol-derived nanoparticles in selective organic transformations, particularly hydrogenation processes.