Surfactant‐Free Palladium Nanoparticles Encapsulated in ZIF‐8 Hollow Nanospheres for Size‐Selective Catalysis in Liquid‐Phase Solution

Abstract Encapsulation of surfactant‐free Pd nanoparticles (NPs) in the metal–organic framework material ZIF‐8 hollow nanospheres was achieved. Pd@ZIF‐8 hollow nanospheres showed excellent size‐selective catalytic properties in the liquid‐phase hydrogenation of olefins. As a result of the uniform pore size of the ZIF‐8 shell (apertures of 3.4 Å), the catalyst showed high activity for the hydrogenation of 1‐hexene (1.9×8.2 Å) but very low activity for larger molecules such as cis ‐cyclooctene (5.3×5.5 Å), trans ‐stilbene (4.2×11.3 Å), and triphenylethylene (9.1×9.2 Å). Other surfactant‐free noble‐metal nanoparticles could also be employed to produce NPs@MOFs for catalysis.