We report a simple and sustainable protocol for the synthesis of monodisperse rhodium (Rh), ruthenium (Ru), and palladium (Pd) metal nanoparticles supported on fibrous nanosilica (KCC-1). In this protocol, use of expensive dendrimers was replaced by inexpensive polyethylenimine (PEI) to produce highly monodispersed supported metal nanocatalysts. First, KCC-1 was covalently functionalized by PEI and then metal(II) salts were loaded on KCC-1-PEI material to have complexation of metal ions with amines of PEI. Reduction of metal(II) ions by NaBH 4 yielded metal(0) nanoparticles supported on KCC-1. As-synthesized metal nanoparticles supported on PEI functionalized KCC-1, named KCC-1-PEI/Rh, KCC-1-PEI/Ru, and KCC-1-PEI/Pd, were characterized by transmission electron microscopy (TEM) for particle size and their distribution, N 2 sorption studies for surface area, pore sizes and pore volume, thermogravimetric analysis for PEI loading, and solid state NMR for its covalent attachment. These nanocatalysts were then evaluated for the hydrogenation of phenylacetylene and styrene. They showed good catalytic activities under mild pressure, at room temperature and notably in a very short period of time. Catalysts were also recyclable several times with negligible loss of activity, indicating their good stability that is due to PEI functionalization as well as fibrous nature of KCC-1 support.
The combination of ultrasmall nanoparticles and pseudosingle atoms of gold (Au) and fibrous nanosilica (KCC-1) enabled the design of KCC-1-APTS/Au nanocatalysts with very high turnover numbers (TONs).
Fibrous nanosilica (KCC-1) supported ultrasmall platinum (Pt) nanoparticles (KCC-1/Pt) were prepared as novel nanocatalysts for hydrogenation reactions. The catalysts displayed high activity for the hydrogenation of 3-nitrostyrene with extraordinary selectivity. KCC-1-PEI/Pt (1%) was specifically found to be selective towards reduction to 3-vinylaniline, whereas 10% and 5% Pt loaded on KCC-1-PEI showed high activity and selectivity towards 3-ethylaniline. The role of platinum nanoparticle size on the selectivity of the catalysts was studied. We observed that catalysts with sub-nanometer Pt or pseudosingle atoms of Pt showed excellent selectivity, which decreased drastically with increase in particle size.Although most catalysts offer good activity or selectivity, these KCC-1 based catalysts offer both high activity and selectivity. The reaction proceeded smoothly at room temperature and KCC-1/Pt nanocatalysts showed a wide substrate scope for hydrogenation reactions under mild conditions, making protocols green and sustainable.
This work reports a cost-effective and sustainable protocol for the carbonylative Suzuki–Miyaura cross-coupling reaction catalyzed by palladium nanoparticles (Pd NPs) supported on fibrous nanosilica (KCC-1) with very high turnover number.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.