Screening of Soluble Rhodium Nanoparticles as Precursor for Highly Active Hydrogenation Catalysts: The Effect of the Stabilizing Agents

摘要: We report the preparation of rhodium nanoparticles (NPs) stabilized by 1-octadecanethiol (ODT), polyvinyl alcohol (PVA), and tetraoctylammonium bromide (TOAB), their application for hydrogenation catalysis. The three metal–ligand systems correspond to different mechanism NPs stabilization via strong covalent linkage, chemisorbed atoms electrostatic interactions, respectively. found a effect interaction between stabilizer surface metal nanoparticle on catalytic activity. Rh were studied as soluble catalysts precursors synthesis supported catalysts. All tested in cyclohexene under similar conditions model reaction. Generally, Rh–ODT inactive, Rh–PVA exhibited distinct activities solution (aqueous biphasic catalysis) catalyst, Rh–TOAB after immobilization. This last result opens opportunity highly active NP both heterogeneous catalyst. Additionally, stability depends choice ligand functionalization support before By optimizing catalyst reaction conditions, turnover frequencies high 700,000 h−1 where observed stable recyclable