Palladium nanoparticles stabilized by novel choline-based ionic liquids in glycerol applied in hydrogenation reactions

Abstract

Palladium nanoparticles stabilized by choline-based ionic liquids in glycerol were prepared from Pd(II) precursors by simply heating at 80 °C under argon; in this process, the water present in the ionic liquid was found to be the responsible for the reduction of Pd(II) into zero-valent palladium species. Palladium nanoparticles were fully characterized in both liquid phase and solid state. The as-prepared metal nanoparticles exhibited remarkable catalytic activity in hydrogenation processes for a significant variety of functional groups (alkenes, alkynes, nitro derivatives, benzaldehydes, aromatic ketones). Highlights  Palladium nanoparticles in glycerol stabilized by novel choline-based ionic liquids.  Characterization of palladium nanoparticles both in solid and liquid phase.  Palladium nanoparticles showing high catalytic activity in hydrogenation reactions.  Selective hydrogenations for non-conjugated alkynes.  Efficient reduction of carbonyl derivatives.

Palladium Nanoparticles in Polyols: Synthesis, Catalytic Couplings, and Hydrogenations

“…This catalytic system is even more interesting towards the hydrogenation of the carbonyl groups which can be reduced under relatively smooth conditions (Scheme 16). 188 Scheme 16. Hydrogenation of nitro and carbonyl groups catalyzed by PdIL NPs in glycerol.…”

“…Hydrogenation of nitro and carbonyl groups catalyzed by PdIL NPs in glycerol. 188 Bimetallic nanoparticles also have been synthetized in alternative solvents for catalytic proposes as hydrogenation reactions. 88,190 They represent an attractive catalytic system thanks to the synergistic effects between both metal partners; the addition of a "guest" to a "host" metal in a same entity could modify its electronic properties (by charge transfer, orbital hybridization…) and/or structure (alloy, core shell... With the aim of studying reactivity-structure relationships, the as-prepared BMNPs were tested in the semihydrogenation of phenylacetylene and diphenylacetylene.…”

“…Hydrogenation processes catalyzed by PdQN NPs in glycerol 79. Choline based ionic liquids in neat glycerol were also used as stabilizers for PdNPs in glycerol 188. Nanocatalysts were synthesized from [PdCl 2 (COD)] as Pd precursor and choline Ntosylalaninate as stabilizer with a ratio Pd/IL (1:17) under Ar atmosphere at 80 °C overnight, leading to nanoparticle mean diameter sizes of 1.7 ± 0.6 nm.…”

“…Thus, the more hindered substrate 1,2,3,4,5-pentamethylcyclopentadiene was selectively reduced into the cyclopentene derivative under 20 bar of H 2 pressure (Scheme 15). Hydrogenation of alkenes and alkynes catalyzed by PdNPs stabilized by choline derivative in glycerol 188.…”

Synthesis of cobalt, palladium, and rhenium nanoparticles

“…In yet another study, a mixture of PdCl 2 (cod) and choline-based derivative such as choline chloride or choline N-tosylalaninate were dissolved in glycerol and stirred under Ar at 80 °C for 18 h, which resulted in the formation of PdNPs. These PdNPs were welldispersed because the supramolecular structure of glycerol effectively prevents the agglomeration of NPs [120]. Pd nanostructures are also synthesized using a seed-mediated technique [121].…”