Structure and Properties of Bimetallic Colloids Formed in Polystyrene-block-Poly-4-vinylpyridine Micelles: Catalytic Behavior in Selective Hydrogenation of Dehydrolinalool

Bronstein, Lyudmila M.; Chernyshov, Dmitrii M.; Volkov, I. O.; Ezernitskaya, Marina G.; Valetsky, Pyotr M.; Matveeva, Valentina G.; Sulman, Esther M.

doi:10.1006/jcat.2000.3039

Cited by 111 publications

(51 citation statements)

References 48 publications

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“…Seregina et al [21] developed monometallic and bimetallic colloids stabilized in the micellar core of polystyrene-blockpoly-4-vinylpyridine (PS-b-P4VP) in toluene for hydrogenations. The same metal-polymer systems were studied by some of us in partial hydrogenation of acetylene alcohol (dehydrolinalool with terminal triple bond) [22,23] and showed selectivity above 99%. Pyridine is known [24] to increase selectivity in alkyne hydrogenation to alkene due to the increased metal electron density leading to decreased alkene adsorption.…”

Section: Introductionmentioning

confidence: 98%

Palladium nanoparticles stabilized in block-copolymer micelles for highly selective 2-butyne-1,4-diol partial hydrogenation

Semagina

Joannet

Parra

et al. 2005

Applied Catalysis A: General

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Pd nanoparticles (2 nm) stabilized in the micelle core of poly(ethylene oxide)-block-poly-2-vinylpyridine were studied in 2-butyne-1,4-diol partial hydrogenation. Both unsupported micelles (0.6 kg Pd /m 3 ) and supported ones on g-Al 2 O 3 (0.042 wt.% Pd) showed nearly 100% selectivity to 2-butene-1,4-diol up to 94% conversion. The only side product observed was 2-butane-1,4-diol. The catalysis was ascribed to Pd nanoparticles' surface modified by pyridine units of micelles and alkali reaction medium (pH of 13.4). TOFs over the unsupported and supported catalysts were found to be 0.56 and 0.91 s À1 (at 323 K, 0.6 MPa H 2 pressure, solvent 2-propanol/water = 7:3), respectively. Reaction kinetics fit the Langmuir-Hinshelwood model assuming weak hydrogen adsorption. The experiments on the catalyst reuse showed that Pd nanoparticles remain inside the micelle core, but the micelles slightly desorbed (less then 5%) during the catalytic run. #

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Section: Introductionmentioning

confidence: 98%

Palladium nanoparticles stabilized in block-copolymer micelles for highly selective 2-butyne-1,4-diol partial hydrogenation

Semagina

Joannet

Parra

et al. 2005

Applied Catalysis A: General

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“…MBE is an important intermediate in the synthesis of vitamins A and E and perfumes. 17 Solvent free conditions were applied as done on an industrial scale, while a majority of the existent studies of similar reactions are performed in a solvent 12,18,19 giving rise to solvent effects.…”

Section: Introductionmentioning

confidence: 99%

Three-Phase Catalytic Hydrogenation of a Functionalized Alkyne: Mass Transfer and Kinetic Studies with in Situ Hydrogen Monitoring

Bruehwiler¹,

Semagina²,

Grasemann³

et al. 2008

Ind. Eng. Chem. Res.

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Systematic studies of mass transfer interactions with intrinsic reaction kinetics were performed for the threephase selective hydrogenation of 2-methyl-3-butyn-2-ol (MBY) to 2-methyl-3-buten-2-ol (MBE) over a modified Pd/CaCO 3 catalyst under solvent free conditions. Hydrogen concentration in the liquid phase (C H2,b ) was monitored in situ during the catalytic reaction by means of the "Fugatron" analyzer. Reactions were carried out in an autoclave at different stirring rates at two concentrations of hydrogen (5 and 13 mol · m -3 ). For stirring speeds higher than 1500 rpm no influence of gas-liquid mass transfer was observed. Hydrogen liquid-solid (L-S) mass transfer was found to be negligible, whereas the MBY mass L-S transfer becomes important at high MBY conversions at high hydrogen concentration. Low stirrer speed caused the reaction rate and MBE selectivity to decrease. No internal mass transfer limitations were observed, and conditions for the kinetic regime were found. The kinetics modeled followed the Langmuir-Hinshelwood mechanism and was consistent with the experimental data.

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“…52 -58 It was suggested that the NR 4 + salts were formed in high local concentration at the reduction centre as an efficient ligand shell to provide the colloids with redispersibility in organic solvents and prevent their aggregation. 55,56 In this part, Rh organosol 2 was prepared according to Bönnemann's method (see Fig.…”

Section: Colloidal Catalyst D: Rh Organosol 2/ligand Amentioning

confidence: 99%

Evidence of colloidal rhodium formation during the biphasic hydroformylation of 1-octene with thermoregulated phase-transfer phosphine rhodium(I) catalyst

Wen¹,

Bönnemann²,

Jiang³

et al. 2005

Appl. Organometal. Chem.

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A thermoregulated phase-transfer (TRPT) Rh(I) complex catalyst A prepared from Rh(acac)(CO) 2 and a thermoregulated ligand CH 3 (OCH 2 CH 2 ) m PPh 2 (M w = 918) was applied to the biphasic hydroformylation of 1-octene, and a high activity with an aldehyde yield of 97.5% was demonstrated. After three recycling steps, the aldehyde yield gradually decreased. Transmission electron microscopy (TEM) revealed that after the first cycle Rh colloids were generated in situ in the aqueous phase, and in subsequent runs Ostwald ripening occurred. An independently prepared colloidal Rh(0) TRPT catalyst D also exhibited high hydroformylation activity under identical experimental conditions, and after two times of recycling an activity decrease was also observed. It is suggested that in situ from Rh(acac)(CO) 2 colloidal Rh particles are generated, which demonstrate thermomorphic behaviour and a high hydroformylation activity. Subsequently, agglomeration processes result in an activity decay, as observed in the TRPT Rh(I) complex catalyst system.

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Structure and Properties of Bimetallic Colloids Formed in Polystyrene-block-Poly-4-vinylpyridine Micelles: Catalytic Behavior in Selective Hydrogenation of Dehydrolinalool

Cited by 111 publications

References 48 publications

Palladium nanoparticles stabilized in block-copolymer micelles for highly selective 2-butyne-1,4-diol partial hydrogenation

Palladium nanoparticles stabilized in block-copolymer micelles for highly selective 2-butyne-1,4-diol partial hydrogenation

Three-Phase Catalytic Hydrogenation of a Functionalized Alkyne: Mass Transfer and Kinetic Studies with in Situ Hydrogen Monitoring

Evidence of colloidal rhodium formation during the biphasic hydroformylation of 1-octene with thermoregulated phase-transfer phosphine rhodium(I) catalyst

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