Preparation of metallic Pd nanoparticles using supercritical CO₂ deposition: An efficient catalyst for Suzuki cross-coupling reaction

Ligand-free palladium nanoparticles supported on multi-walled carbon nanotubes (Pd/MWCNT) were prepared by the supercritical carbon dioxide (scCO₂) deposition method using a novel scCO₂-soluble Pd organometallic complex as a precursor. The precursor with the perfluoroalkyl chain group was synthesized and identified by microanalytic methods. The deposition was carried out at the temperature of 363.15 K and pressure of 27.6 MPa CO₂. The prepared metallic nanoparticles were obtained with an average size of 2 nm. Pd/MWCNT was utilized as a heterogeneous catalyst in Suzuki cross-coupling reaction. The nanocatalyst was found very effective in Suzuki reaction and it could also be recovered easily from the reaction media and reused over several cycles without significant loss of catalytic activity under mild conditions.