Search results for "Pd nanoparticles"

showing 10 items of 12 documents

Structure Sensitivity of 2-Methyl-3-butyn-2-ol Hydrogenation on Pd: Computational and Experimental Modeling

2014

In the frame of DFT paradigms, the adsorption of 2-methyl-3-butyn-2-ol (MBY) and 2-methyl-3-buten-2-ol (MBE) on a Pd-30 cluster, including both {100} and {111} faces, was studied along with the pathways involved in the hydrogenation, taking place on plane and low coordination (corner/edge) sites of given MBY/Pd-30 and MBE/Pd-30 surface configurations. The calculated energetics, further validated by gas-phase and water-assisted gas-phase MBY and MBE hydrogenation, performed on well-defined size and shape-controlled Pd nanoparticles supported on SiO2, were able to explain the origin of the structure sensitivity and the high selectivity characterizing the title reaction when occurring in aqueo…

Aqueous solutionChemistryHigh selectivitySurfaces Coatings and FilmsElectronic Optical and Magnetic Materials2-methyl-3-butyn-2-olCrystallographyGeneral EnergyAdsorptionComputational chemistryPd nanoparticlesCluster (physics)MoietySensitivity (control systems)Physical and Theoretical ChemistryThe Journal of Physical Chemistry C
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Advances in biogenic synthesis of palladium nanoparticles

2016

Green approaches for the synthesis of nanoparticles provide advantages due to the fact that green protocols are benign and environmentally friendly. Among various green recipes, biogenic synthesis of nanoparticles has recently emerged as an active area of research due to the simplicity of this method, with cost effective protocols, higher potential of reduction and low toxic effect on human health and the environment. Moreover, the biogenic reduction occurs at physiological conditions of temperature and pressure. The raw materials are easily available and therefore, the reaction can easily be scaled up. This paper presents a review to give an idea about the most reliable, cost-effective and…

ChemistryGeneral Chemical EngineeringNanoparticlePalladium nanoparticlesNanotechnology02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesEnvironmentally friendly0104 chemical sciencesHuman healthTemperature and pressurePd nanoparticles0210 nano-technologyMetal nanoparticlesRSC Advances
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Pd nanoparticles formation inside porous polymeric scaffolds followed by in situ XANES/SAXS

2015

International audience; Simultaneous time-resolved SAXS and XANES techniques were employed to follow in situ the formation of Pd nanoparticles from palladium acetate precursor in two porous polymeric supports: polystyrene (PS) and poly(4-vinyl-pyridine) (P4VP). In this study we have investigated the effect of the use of different reducing agents (H-2 and CO) from the gas phase. These results, in conjunction with data obtained by diffuse reflectance IR (DRIFT) spectroscopy and TEM measurements, allowed us to unravel the different roles played by gaseous H-2 and CO in the formation of the Pd nanoparticles for both PS and P4VP hosting scaffolds

HistoryMaterials scienceAbsorption spectroscopyNanoparticlechemistry.chemical_elementreduction02 engineering and technologypolystyrene010402 general chemistry01 natural sciencesEducationP4VPchemistry.chemical_compoundPdPd nanoparticles formation inside porous polymeric scaffoldspaladumchemistry.chemical_classification[PHYS]Physics [physics]Small-angle X-ray scatteringnanoparticlein situSAXS XANES Pd paladum nanoparticle polystyrene P4VP DRIFT TEM reduction in situSAXSPolymer021001 nanoscience & nanotechnologyXANESXANES0104 chemical sciencesComputer Science ApplicationsCrystallographyDRIFTchemistryChemical engineeringTEMPolystyreneDiffuse reflection0210 nano-technologyPalladium
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Polypyrrole–palladium nanoparticles composite as efficient catalyst for Suzuki–Miyaura coupling

2012

International audience; Synthesis of a new hybrid material (Pd/PPy) composed of polypyrrole globules with uniformly incorporated Pd nanoparticles via direct redox reaction between pyrrole and Pd(NH3)(4)Cl-2 in water has been recently reported (V.A. Zinovyeva, M.A.Vorotyntsev, I. Bezverkhyy, D. Chaumont, J.-C. Hierso, Adv. Funct. Mater. 21 (2011) 1064-1075). In the actual study, this procedure has been extended to synthesize a series of Pd/PPy powders with variable palladium content and morphological parameters. Depending on the monomer-to-oxidant ratio in reaction mixture, average diameters of Pd and PPy particles may change in the ranges of 1.25-1.45 and 27-62 nm, respectively, the Pd conc…

Inorganic chemistryPVP-PD NANOPARTICLESchemistry.chemical_elementNanoparticle010402 general chemistryHeterogeneous catalysisPolypyrrole01 natural sciencesCatalysisCatalysischemistry.chemical_compoundHETEROGENEOUS PALLADIUMWATERHIGHLY-ACTIVE CATALYSTAQUEOUS-MEDIAHYDROGENATIONPhysical and Theoretical ChemistryHECKNanocomposite010405 organic chemistryProcess Chemistry and TechnologyPOLYMER0104 chemical sciencesRECYCLABLE CATALYSTchemistryReagentHybrid materialLIGAND-FREEPalladiumJournal of Molecular Catalysis A: Chemical
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Formation and Growth of Pd Nanoparticles Inside a Highly Cross-Linked Polystyrene Support: Role of the Reducing Agent

2014

Simultaneous time-resolved SAXS and XANES techniques were employed to follow in situ the formation of Pd nanoparticles in a porous polystyrene support, using palladium acetate as a precursor and gaseous H2 or CO as reducing agents. These results, in conjunction with data obtained by diffuse reflectance UV–vis and DRIFT spectroscopy and TEM measurements, allowed unraveling of the different roles played by gaseous H2 and CO in the formation of the Pd nanoparticles. In particular, it was found that the reducing agent affects (i) the reduction rate (which is faster in the presence of CO) and (ii) the properties of the hosted nanoparticles, in terms of size (bigger with CO), morphology (spherica…

Materials scienceExtended X-ray absorption fine structureReducing agentSmall-angle X-ray scatteringchemistry.chemical_elementNanoparticlePd nanoparticles; SAXS; EXAFSSAXSXANESSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsCrystallographychemistry.chemical_compoundEXAFSGeneral EnergyPd nanoparticleschemistryChemical engineeringPalladium nanoparticles time-resolved X-ray Absorption Spectroscopy Small Angle X-ray Spectroscopy Transmission Electron MicroscopyDiffuse reflectionPolystyrenePhysical and Theoretical ChemistryPalladium
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MOF-Mediated Synthesis of Supported Fe-Doped Pd Nanoparticles under Mild Conditions for Magnetically Recoverable Catalysis**

2020

Metal–organic framework (MOF)-driven synthesis is considered as a promising alternative for the development of new catalytic materials with well-designed active sites. This synthetic approach is used here to gradually transform a new bimetallic MOF, with Pd and Fe as the metal components, by the in situ generation of aniline under mild conditions. This methodology results in a compositionally homogeneous nanocomposite formed by Fe-doped Pd nanoparticles that, in turn, are supported on iron oxide-doped carbon. The nanocomposite has been fully characterized by several techniques such as IR and Raman spectroscopy, TEM, XPS, and XAS. The performance of this nanocomposite as an heterogeneous cat…

Materials scienceIron09.- Desarrollar infraestructuras resilientes promover la industrialización inclusiva y sostenible y fomentar la innovaciónNanoparticle010402 general chemistryHeterogeneous catalysis01 natural sciences7. Clean energyCatalysisCatalysisNitrobenzenechemistry.chemical_compoundLight sourceAnilineCatàlisiQUIMICA ANALITICAmedia_common.cataloged_instanceUser FacilityEuropean unionBimetallic stripmedia_commonX-ray absorption spectroscopyNanocomposite010405 organic chemistryOrganic ChemistryGeneral ChemistryMetal-organic frameworks0104 chemical sciences12.- Garantizar las pautas de consumo y de producción sostenibleschemistryChemical engineeringFe dopedPd nanoparticlesNanoparticlesMaterials nanoestructuratsNational laboratoryHumanitiesPalladium
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Permanent magnetism in apoferritin-encapsulated Pd nanoparticles

2007

Pd nanoparticles have been prepared within the apoferritin cavity. X-Ray powder diffraction, transmission electronic microscopy and magnetization measurements have been used for characterizing the nanoparticles. The nanoparticles exhibit permanent magnetism at room temperature.

Materials scienceMagnetismNanoparticlechemistry.chemical_elementNanotechnologyTransmission electronic microscopyGeneral Chemistryequipment and suppliesMagnetizationNuclear magnetic resonanceTransition metalchemistryPd nanoparticlesMaterials Chemistryhuman activitiesPowder diffractionPalladiumJ. Mater. Chem.
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Structural and magnetic characterization of Pd nanoparticles encapsulated in apoferritin

2010

Pd nanoparticles exhibiting permanent magnetism at room temperature have been prepared within the apoferritin cavity. Pd nanoparticles in air and under an inert atmosphere were synthesized to study the influence of the aerobic and anaerobic conditions in the final magnetic properties. The surface of nanoparticles as well as the type of crystalline phase could determine the magnetic properties. X-ray powder diffraction, including Debye-function analysis, transmission electronic microscopy, and magnetization measurements have been used for characterizing the nanoparticles.

Materials scienceMagnetismPhysics::OpticsNanoparticleBioengineeringMagneticsMagnetizationX-Ray DiffractionPhase (matter)General Materials ScienceElectrical and Electronic EngineeringInert gasMechanical EngineeringTemperatureGeneral Chemistryequipment and suppliesCharacterization (materials science)CrystallographyModels ChemicalChemical engineeringMechanics of MaterialsPd nanoparticlesApoferritinsNanoparticleshuman activitiesPalladiumPowder diffraction
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Physico-chemical characterization of Pd nanoparticles synthesized in w/o microemulsions

1998

Abstract The long time stability of surfactant-coated Pd nanoparticles in w/o microemulsions has been investigated. It has been proven that in suitable conditions, the use of the functionalized surfactant Pd(AOT)2 allows to obtain very stable nanosized Pd particles and to finely control their average size.

Materials scienceNanostructureSmall-angle X-ray scatteringBioengineeringNanotechnologyCharacterization (materials science)BiomaterialsChemical engineeringPulmonary surfactantMechanics of MaterialsTransmission electron microscopyPd nanoparticlesParticleMicroemulsionMaterials Science and Engineering: C
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Enhanced H2O2 production over Au-rich bimetallic Au-Pd nanoparticles on ordered mesoporous carbons

2015

1 figures, 3 tables.-- © 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

Ordered carbonMaterials scienceHydrogenInorganic chemistrychemistry.chemical_elementNanoparticleGeneral ChemistryHydrogen peroxideCatalysisCatalysisMetalchemistry.chemical_compoundchemistryPd nanoparticlesvisual_artAuPd alloysAcid treatmentvisual_art.visual_art_mediumNanoparticlesHydrogen peroxideMesoporous materialCMK-3Bimetallic stripCatalysis Today 248: 48-57 (2015)
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