Hierarchical porous Pd/HS-1 zeolite as an efficient and reusable catalysts for Suzuki-Miyaura reaction.

The Pd/HS-1 catalyst with hollow hexagonal prism structure was prepared and applied to Suzuki coupling reaction, achieving over 99% conversion of bromobenzene in a short period of time. [Display omitted] • Hierarchical porous zeolites were prepared by dissolution recrystallization and then loaded with Pd nanoparticles by impregnation. • The proper acid sites as well as metal-zeolite interactions can modulate the electronic state of Pd, and thus improve the conversion of bromobenzene. • The size of metal nanoparticles plays a decisive role in metal-catalyzed heterogeneous reactions, due to Pd binding energy varied with changed sizes. • 2.0Pd/HS-1 provides excellent catalytic performance in non-toxic reaction media, mild reaction conditions, and short reaction times while achieving recyclability. The Suzuki-Miyaura reaction is one of the most effective routes for the construction of carbon–carbon bonds, due to the obvious advantages of mild reaction conditions, wide range of functional group tolerance, simplicity of operation, and environmental friendliness. However, these reactions highly depend on the development of the active and stable catalysts. Herein, the hollow hexagonal prismatic silicalite-1 (HS-1) zeolite-supported palladium nanoparticles (Pd NPs) were synthesized and applied as a catalyst in Suzuki-Miyaura reaction. The experimental results show that 2.0Pd/HS-1 is an efficient and stable catalyst, which can achieve a high conversion rate (>99.9 %) in a short time (45 min) and can be recycled. Further studies show that 2.0Pd/HS-1 has abundant mesopores, which are favorable for exposing more active sites and promoting the transfer of reactants around the catalysts, thus improving the contact opportunities between the catalysts and the feedstock. Moreover, its proper acid sites as well as metal-zeolite interactions can modulate the electronic state of Pd, and thus improve the conversion of bromobenzene. This work provides new insights into the design, synthesis and applications of highly efficient hollow silicalite-1 zeolite loaded metal catalysts. [ABSTRACT FROM AUTHOR]