A PPh3 modified-chitosan support was synthesized by the acid-mediated addition reaction of the tris(4-vinylphenyl)phosphane ligand (3vPPh3) and chitosan (CS). The material was loaded with Pd(OAc)2 to ...furnish a supported Pd catalyst (Pd/PPh3-CS), which was characterized by FT-IR, ICP-MS, TGA, XPS, SEM, TEM and N2 adsorption–desorption analysis. The catalyst showed a high catalytic activity, wide substrate compatibility and good recyclability in heterogeneous Suzuki–Miyaura cross coupling reactions.
N‐doped mesoporous carbon spheres (NHMC@mSiO2) encapsulated in silica shells were prepared by emulsion polymerization and domain‐limited carbonization using ethylenediamine as the nitrogen source, ...and Ru−Ni alloy catalysts were prepared for the hydrogenation of α‐pinene in the aqueous phase. The internal cavities of this nanomaterial are lipophilic, enhancing mass transfer and enrichment of the reactants, and the hydrophilic silica shell enhances the dispersion of the catalyst in water. N‐doping allows more catalytically active metal particles to be anchored to the amphiphilic carrier, enhancing its catalytic activity and stability. In addition, a synergistic effect between Ru and Ni significantly enhances the catalytic activity. The factors influencing the hydrogenation of α‐pinene were investigated, and the optimum reaction conditions were determined to be as follows: 100 °C, 1.0 MPa H2, 3 h. The high stability and recyclability of the Ru−Ni alloy catalyst were demonstrated through cycling experiments.
Highly‐dispersed Ru−Ni nanocatalysts were prepared by a multi‐step reaction including emulsion polymerization, domain‐limited carbonization, and impregnation‐deposition of metals.This nanocatalyst exhibits excellent catalytic activity and selectivity for α‐pinene hydrogenation under the mild conditions. The high stability and recyclability of the catalyst were demonstrated through cycling experiments.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Porous organic polymers (CPOL-BINAPa&PPh3 and CPOL-BINAPa&PhPh3) were synthesized via copolymerization of a divinyl-functionalized phosphoramidite ligand (2vBINAPa) and various trivinyl-monomers ...(3vPPh3 and 3vPhPh3). After metalation with Rh(acac)CO2, Rh/CPOL-BINAPa&PPh3 showed the better catalytic performance than Rh/CPOL-BINAPa&PhPh3 in the heterogeneous hydroformylation. A corresponding catalytic Rh–H species has been investigated by FT-IR and/or NMR spectroscopy. The results indicated that two kinds of Rh–H species were formed in the Rh/CPOL-BINAPa&PPh3 catalyst. The ee species containing the BINAPa ligand contributed to the high activity in hydroformylation. The three P coordinated Rh–H species consisting of BINAPa and PPh3 ligands resulted in the high regioselectivity owing to the steric hindrance. Furthermore, the DFT calculations and cycle test results of the catalysts indicated that the PPh3 moieties could improve the stability of the Rh–H species, prevent dissociation of Rh from the BINAPa moieties and reduce the loss of Rh in the catalytic process.
Unconventional ferroelectricity exhibited by Bi-based nanosheets presents potential opportunities in catalytic fields, whereas the polarization characteristic remains controversial in ...electrocatalysis. Herein, we report a novel ferroelectric catalyst of polarized Bi2Fe4O9 nanoplates through the corona poling method after hydrothermal and calcination processes, exhibiting super catalytic activity for water splitting controlled by ferroelectric switching and special two-dimensional (2D) structure. The ferroelectric polarization depending on high voltage greatly enhances the activity of polarized Bi2Fe4O9 nanoplates for hydrogen evolution reaction (HER) with a 98 mV positive shift of overpotential compared to the unpolarized Bi2Fe4O9 nanoplates in alkaline conditions. And after long-term stability tests, the polarized Bi2Fe4O9 nanoplates exhibit excellent durability for hydrogen production. Our results show that the effect of ferroelectric polarization of Bi2Fe4O9 nanoplates enhances the electrocatalytic hydrogen evolution, which provide a new strategy for broad the application of ferroelectric materials.
The polarized Bi2Fe4O9 nanoplates boost the hydrogen evolution reaction (HER) with a 98 mV positive shift of overpotential compared to the unpolarized Bi2Fe4O9 nanoplates ascribed to the adjusted d-band center and special two-dimensional (2D) structure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•The polyether chains improve the solubility of isobutane.•The bonding between polyether and isobutane is simulated by DFT.•Polyether-based acidic DES can catalyze isobutane/isobutene ...alkylation.•High-quality alkylated gasoline is afforded under a low alkane-to-alkene ratio.•DES catalyst exhibits good recycling capacity.
In this study, the solubility of isobutane in different types of polyethers was evaluated. Macroscopic and microscopic simulations of molecular bonding of isobutane to polyethers such as PEG200 and PPG200 were performed. The solubility of isobutane in different polyethers with different degrees of polymerization was investigated. The solubility of isooctane—the main alkylated gasoline product—in different polyethers was also determined. Based on the solubility ratios of isobutane and isooctane in the same polyether, PEG200 was selected as a component of a deep eutectic solvent (DES), which was then used for catalyzing the alkylation of isobutane and isobutene to prepare alkylated gasoline. Owing to the good solubility of isobutane in polyether, a three-component Brønsted–Lewis acidic DES catalyst, InCl3/PEG200/TfOH, could be used to prepare high-quality alkylated gasoline (conversion rate: 89.12%, C8 selectivity: 82.83%) at a low alkane-to-alkene ratio (5:1). Moreover, owing to its poor solubility to isooctane, the DES catalyst could be easily separated from alkylated gasoline. This DES catalyst retains its high catalytic activity over seven cycles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Conventional acidic catalysts for isobutane and isobutene alkylation exhibit low alkylate selectivity. Herein, we employed an acidic deep eutectic solvent, consisting of trifluoromethanesulfonic acid ...and taurine, in polyethylene glycol as the catalyst. Its high conversion rate and selectivity, as well as recyclability, make it suitable for alkylate gasoline preparation.
The first organic–inorganic lacunary polyoxometalate catalytic oxidation system with H
2
O
2
as an oxidant for the preparation of aliphatic carboxylic acids from primary alcohols has been developed. ...This new catalytic system not only exhibits good catalytic activity with high selectivity toward acids, but also satisfactorily resolves the separation of the catalyst for reuse.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Alpha-pinene is an important forest chemical resource, and the cis-pinane obtained by its hydrogenation reaction is used in spices, medicine, and other industries. A hollow nanospheric material with ...amphiphilic properties in a two-sided structure was prepared, with a nitrogen-doped carbon layer towards the inside and mesoporous silica in the outer layer of the nanospheres. The amphiphilic catalyst with non-precious nickel as the active component was synthesized by loading nickel onto the nanospheres using a simple impregnation method and applied to the aqueous phase hydrogenation reaction of α-pinene. The mesoporous structure of the catalyst shortened the mass transfer distance and thus reduced the mass transfer resistance. The nitrogen atoms doped in the carbon matrix provided anchor points for stabilizing the metal nanoparticles; the hydrophilic outer surface and hydrophobic hollow cavity enabled the catalyst to be well dispersed in water while still enriching the organic matter in aqueous solution. The effect of various reaction conditions on the catalytic reaction was investigated. The catalysts showed excellent activity and good stability, suggesting a new green and efficient method for more effective exploitation of biomass pine resin resources, and providing a reference for expanding the application of non-precious metal catalysts.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A multifunctional nanomaterial (Fe3O4@SiO2@CX@NH2) comprising a magnetic core, a silicon protective interlayer, and an amphiphilic silica shell is successfully prepared. Ru nanoparticles catalyst ...loaded on Fe3O4@SiO2@CX@NH2 is used in hydrogenation of α‐pinene for the first time. The novel nanomaterial with amphipathy can be used as a solid foaming agent to increase gas–liquid–solid three‐phase contact and accelerate the reaction. Under the mild conditions (40 °C, 1 MPa H2, 3 h), 99.9% α‐pinene conversion and 98.9% cis‐pinane selectivity are obtained, which is by far the best results reported. Furthermore, the magnetic nanocomposite catalyst can be easily separated by an external magnet and reused nine times with high selectivity maintaining.
Amphiphilic core–shell magnetic nanocomposite catalyst used in α‐pinene hydrogenation exhibits excellent cis‐pinane selectivity and recyclability under mild conditions.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
