Carbon Nanofiber-Supported Pd Catalysts for Heck Reaction: Effects of Support Interaction

Well-dispersed palladium nanoparticles were synthesized by the polyol reduction method. In order to prepare stable and reusable heterogeneous catalysts, palladium nanoparticles were supported on platlet carbon nanofiber (pCNF), fishbone carbon nanofibers (fCNF), and tubular carbon nanofibers (tCNF). It was found that the Pd loading and the particles size as well as the amount of Pd leaching during the Heck reaction were strongly related to the potential difference between the CNF surfaces and the palladium colloids. Pd leaching in the Heck reaction can be significantly suppressed by increasing potential difference between the CNF surfaces and the palladium colloids during catalyst preparation. The Pd activity decreased exponentially with the Pd particle size.