Palladium nanoparticles stabilized by polyethylene glycol: Efficient, recyclable catalyst for hydrogenation of styrene and nitrobenzene

Partial Hydrogenation of Sunflower Oil-derived FAMEs Catalyzed by the Efficient and Recyclable Palladium Nanoparticles in Polyethylene Glycol

“…3 Results and discussion 3.1 The study of Pd-PEG4000 prepared at different temperatures Based on the previous literatures, polyethylene glycol with molecular weight of 2000-4000 are good catalyst carrier or support for the formation of Pd 0 nanoparticles 17 . Therefore, PEG4000 was used both as catalyst carrier and reductant for Pd 0 .…”

Palladium Nanoparticles within Core-Cross-Linked Polymer Gels for Suzuki Coupling Reactions: from Monomers to Ready-to-Use Catalysts in Two-Steps

“…9,33 Briefly, an absorption band at around 300 nm due to the presence of Pd II ions in solution is observed before the addition of NaBH 4 . 5,[33][34][35] This signal disappears after Pd II ions are quantitatively reduced to Pd 0 upon addition of NaBH 4 . The resulting PdNP also absorb light to a certain extent within the whole range of 300-800 nm, and their maximum absorbance is at a higher wavelength (data not shown).…”

“…The catalytic activity of polymer@PdNPs evaluated on the basis of k obs values revealed the capping agent effect. First, we considered homopolymer 1 in this study not only because it is largely used in organic chemistry laboratories to prepare PdNP for Suzuki coupling reactions, 5,34,36,37 but also because we wanted to compare it with the structurally related counterpart 2. The former is a linear chain of ethylene oxide repeat units, and the latter is a bottlebrush polymer with a hydrophobic methacrylate backbone and short side chains made of ethylene oxide repeat units.…”

“…Aggregation was observed for 1@PdNPs system during the reaction, and it reflected on the low yield of biaryl product. Although PEO (poly(ethylene oxide)) has been often used for this same purpose with satisfactory results, 5 significantly less capping agent is applied here (1/5 of the amount in some cases). All other catalysts were, in general, active in mediating the reaction towards the formation of the expected product, in almost quantitative yields, under relatively mild conditions, after only 4 h ( Table 3, entries 2-6).…”

“…2 The usually high activity of PdNPs is attributed to electronic properties and under-coordination of surface atoms, which are sensitive to particle size and shape, and inter-particle distance and interaction mechanisms. 3 The high surface energy also renders PdNPs systems prone to aggregation and loss of activity [3][4][5] whenever the surface chemistry is not properly controlled. As a consequence, a great deal of effort has been put into the development of simple and effective strategies allowing for precise engineering of surface properties.…”