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 (similar to 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.

Automated summary

This study presents an effective way to fabricate a stable and well-dispersed heterogeneous nanocatalyst by immobilizing small Pd NPs uniformly on the surface of carbon nanotubes, demonstrating excellent catalytic activity for the cross-coupling of organoindium halide with alkyl iodide. It is the first report of utilizing CNT-PdNP nanohybrid catalyst for this specific reaction, indicating potential for diverse efficient catalytic applications using CNT-supported metallic NPs.