Ultrafine palladium nanoparticles supported on poly(4-vinylpyridine)-grafted carbon nanotubes as heterogeneous catalysts for cross-coupling reaction between organoindium halide and alkyl iodide

The rational design of a stable and recyclable nanocatalyst based on robust support for the application in palladium (Pd)-catalyzed coupling reactions always fuels great interest. Pd nanoparticles (NPs) deposited onto carbon nanotubes (CNTs) to form CNT–PdNPs hybrid nanocomposites has been thoroughly studied. And they can serve as heterogeneous catalysts to implement the Pd-catalyzed cross-coupling reactions. However, the utilization of CNT–PdNPs nanohybrids for cross-coupling reaction between organoindium halide and alkyl iodide is a blank area, and no example has been reported. In this work, we provide an effective approach for the fabrication of a Pd-based heterogeneous nanocatalyst, where Pd NPs with small average size (~2.5 nm) are uniformly immobilized on the surface of poly(4-vinylpyridine) (P4VP)-grafted carbon nanotube (CNT). Owing to the uniform distribution of Pd NPs on the CNT surface, high stability and good dispersibility of CNT-g-P4VP/PdNPs composites, the as-fabricated heterogeneous nanocatalyst exhibits excellent catalytic activity for cross-coupling of organoindium halide with alkyl iodide. It is the first report that the CNT–PdNP nanohybrid catalyst is applied to the cross-coupling reaction between organoindium halide and alkyl iodide. This work may pave the way for the construction of CNT-supported metallic NPs for a variety of efficient catalytic applications.