Highly Efficient Zeolite-Supported Pd Catalyst Activated in C–C Cross-Coupling Reaction

The position of Pd species in/on zeolites is crucial for the activity of metal/metal oxide catalysts. It is still a challenge to highly disperse and stabilize the metal species on zeolites and shorten diffusion paths to maintain high catalytic activity. Here, we report an effective strategy for preparing highly efficient zeolite-supported Pd(II) catalysts by positioning Pd(II) species on the surface of a zeolite with an anion framework based on the principle of charge balance. The catalyst was prepared in situ in a C–C cross-coupling reaction. Due to the change in the metal–support interaction, Pd species have migrated from the inside to the surface of the zeolite, which shortens the diffusion path of reactants and thus ensures the high activity of the catalyst. Pd species exhibit aggregation resistance in alkaline systems and tend to be confined in the traps with high charge density. Compared to unactivated Pd@USY, the efficiency of the activated catalysts has at least doubled in catalyzing the Sonogashira and Suzuki–Miyaura reactions. This study represents a new activation approach for zeolite-supported Pd catalysts, which may help to design efficient catalysts.