Search results for " zeolite"

showing 3 items of 23 documents

Butene Isomerization and Double-Bond Migration on the H-ZSM-5 Outer Surface: A Density Functional Theory Study

2011

Isomerization of trans-but-2-ene to cis-but-2-ene and double bond migration of trans-but-2-ene to but-1-ene have been investigated by means of density functional theory calculations on a suitable model of H-ZSM-5 surface. The study has been afforded on outer surface sites by considering the hydroxyl group of either a SiO2(OH)2 or a AlO2H(OH)2 moiety. On these outer surface sites, one alkoxide species occurs as a stable intermediate both along the isomerization and double bond migration pathways. The latter process could also occur via a single-step mechanism, which involves a six-center transition state. The energy barriers of the outer surface processes above do not take any advantage by t…

chemistry.chemical_classificationMFI zeolite outer surface DFTDouble bondHydrogenchemistry.chemical_elementPhotochemistryButeneSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialschemistry.chemical_compoundGeneral EnergychemistryAlkoxideMoietyDensity functional theoryPhysical and Theoretical ChemistryZSM-5IsomerizationThe Journal of Physical Chemistry C
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Electrocatalysis of neurotransmitter catecholamines by 2,4,6-triphenylpyrylium ion immobilized inside zeolite Y supercages

1999

2,4,6-Triphenylpyrylium ions entrapped inside the supercages of Y zeolite exert a remarkable catalytic effect toward the electrochemical oxidation of dopamine and norepinephrine (neurotrasmitter catecholamines) in neutral aqueous media. Domenech Carbo, Antonio, Antonio.Domenech@uv.es

endocrine system diseasesUNESCO::QUÍMICAInorganic chemistryElectrocatalysis ; Trphenylpyrydium ; Y zeolite ; Neurotransmitter ; Catalytic effectNanotechnologyElectrochemistryElectrocatalyst:QUÍMICA [UNESCO]CatalysisCatalytic effectIonNorepinephrine (medication)chemistry.chemical_compoundDopamineCatalytic effectMaterials ChemistrymedicineTrphenylpyrydiumNeurotransmitterNeurotransmitterZeoliteUNESCO::QUÍMICA::Química analíticaY zeoliteMetals and AlloysGeneral ChemistrySurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialschemistryCeramics and Composites:QUÍMICA::Química analítica [UNESCO]Electrocatalysismedicine.drug
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Sorption capacities of the natural and synthetic zeolites for the Cu(II) ions

2015

The sorption of Cu(II) ions onto natural (clinoptilolite) and synthetic (Na-X and Na-P1) zeolites was investigated. The synthetic zeolite samples were obtained from coal fly ash under hydrothermal crystallization conditions. The following issues were studied under batch conditions: the influence of the initial concentration of the Cu(II) ions, dose of zeolites, anion kind, and pH of solution. The experimental data were modelled with the Freundlich, Langmuir, and Dubinin-Radushkevich adsorption isotherms and their goodness-of-fit levels were compared. The affinity of the Cu(II) ions for synthetic zeolites was much higher than for the natural ones. The maximum sorption capacity of the synthet…

synthetic zeolitesclinoptiloliteBCR methodwastewaterCu(II) ion sorptionPolish Journal of Environmental Studies
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