Kinetics and mechanisms of decomposition reaction of hydrogen peroxide in presence of metal complexes

Salem, Ibrahim A.; El-Maazawi, M.; Zaki, Ahmed B.

doi:10.1002/1097-4601(2000)32:11<643::aid-kin1>3.0.co;2-c

Cited by 122 publications

(82 citation statements)

References 157 publications

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“…These species are less reactive than the usual hydroxyl radical involved in autoxidation of lipids and selectively abstracts a hydrogen atom at the bis-allylic position forming the radical intermediate i1 (Scheme 2). On the other hand, hydrogen peroxide in the presence of transition metal ions can efficiently generate molecular oxygen, without necessarily involving intermediate generation of extremely reactive hydroxyl radicals [78,79]. The bis-allylic radical i1 reacts with oxygen preferentially at C9 and C13, forming conjugated (more stable) peroxyl radicals i2(a) and i2(b) (Scheme 2).…”

Section: Oxidation Reaction Of Linoleic Acid Methyl Ester Catalyzed Bmentioning

confidence: 79%

New Insights on the Oxidation of Unsaturated Fatty Acid Methyl Esters Catalyzed by Niobium(V) Oxide. A Study of the Catalyst Surface Reactivity

et al. 2018

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Abstract:The catalytic properties of niobium(V) oxide (Nb 2 O 5 -CBMN) of different grades: amorphous, optical and ultra-pure, untreated or heat-treated at 400, 500, 700 and 900 • C were studied, before and after interaction with H 2 O 2 , by in situ Raman, FTIR-ATR and diffuse reflectance UV-Visible spectroscopy. The presence of different reaction sites for NbO 7 and NbO 8 type systems, which are directly related to surface defects present in different states of crystallization, were fully characterized. The reactivity of different catalysts obtained from niobium(V) oxide was investigated, using the oxidation of methyl linoleate in the presence of hydrogen peroxide as probe reaction. The reaction was followed by GC-MS, as well as by 1 H and 13 C NMR spectrometry and the dominant product was 9-oxo-nonanoic acid methyl ester. A reaction mechanism related to an auto-oxidation process must be occurring, leading initially to the formation of hydroperoxides, which decompose rapidly via Hock-type rearrangement, leading to the formation of aldehydes.

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Section: Oxidation Reaction Of Linoleic Acid Methyl Ester Catalyzed Bmentioning

confidence: 79%

New Insights on the Oxidation of Unsaturated Fatty Acid Methyl Esters Catalyzed by Niobium(V) Oxide. A Study of the Catalyst Surface Reactivity

et al. 2018

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“…[3][4][5][6] La selectividad para la DCPH en la superficie de un sólido es de utilidad para evaluar y comparar la actividad catalítica de sólidos modificados. 3,4 Esta evaluación se realiza asumiendo que la cinética de la DCPH obedece a una ley de pseudo-primer orden, Ecuación 1, a partir de la cual se calcula y se compara la constante de velocidad observada (k obs ) (1) donde [H 2 O 2 ] 0 es para la concentración inicial de peróxido de hidrógeno.…”

Section: Introductionunclassified

Estudio cinético de la descomposición catalizada de peróxido de hidrógeno sobre carbón activado

Paternina

Arias

2009

Quím. Nova

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Recebido em 23/5/08; aceito em 7/11/08; publicado na web em 26/2/06 KINETIC STUDY OF THE CATALYZED DECOMPOSITION OF HYDROGEN PEROXIDE ON ACTIVATED CARBON. The kinetic study of decomposition of hydrogen peroxide catalyzed by activated carbon was carried out. The effect of concentrations of reactants and temperature were experimentally studied. Kinetic data were evaluated using differential method of initial rates of reaction. When a typical kinetic law for reactions in homogeneous phase is used, first order of reaction is obtained for hydrogen peroxide and activated carbon, and activation energy of 27 kJ mol -1 for the reaction was estimated. Experimentally was observed that surface of activated carbon is chemically modified during decomposition of hydrogen peroxide, based on this result a scheme of reaction was proposed and evaluated. Experimental data fits very well to a Langmuir-Hinshelwood kinetic model and activation energy of 40 kJ mol -1 was estimated for reaction in heterogeneous phase.Keywords: decomposition of hydrogen peroxide; initial rate of reaction; kinetic law of Langmuir-Hinshelwood. introducciónLa descomposición catalizada del peróxido de hidrógeno (DCPH), tanto en fase homogénea como heterogénea, es una reacción ampliamente estudiada debido a la alta reactividad de la molécula y al poder oxidante de los productos intermediarios de reacción. 1,2 La DCPH en la superficie de sólidos ocurre selectivamente en sitios activos básicos o reductores o en sitios donde estén involucrados iones de metales tales como, hierro, cerio, manganeso, cobre, cobalto, vanadio, etc., los cuales pueden estar en diferentes estados de oxidación y/o formando complejos. 3-6 La selectividad para la DCPH en la superficie de un sólido es de utilidad para evaluar y comparar la actividad catalítica de sólidos modificados. 3,4 Esta evaluación se realiza asumiendo que la cinética de la DCPH obedece a una ley de pseudo-primer orden, Ecuación 1, a partir de la cual se calcula y se compara la constante de velocidad observada (k obs ) (1) donde [H 2 O 2 ] 0 es para la concentración inicial de peróxido de hidrógeno.Lin y Gurol en 1998 estudiaron la DCPH catalizada por oxido de hierro, 7 y Huang et al. en 2003 estudiaron la descomposición catalizada por carbones activados modificados, 8 encontrando que la tendencia de los datos experimentales se ajustan a una ley ciné-tica de tipo Langmuir-Hinshelwood, como la que se muestra en la Ecuación 2,donde k vel y k h se interpretan como la constante cinética de reacción y la de formación de reactivos a partir de intermediarios, respectivamente; CAT es la relación masa/volumen de carbón activado y [H 2 O 2 ] 0 es la concentración inicial de peróxido de hidrógeno. Sin embargo estos estudios no se realizaron de manera sistemática, esto es, se llevaron a cabo a una sola temperatura y una sola relación masa-volumen de catalizador y además se realizaron pocos experimentos en un pequeño intervalo de concentraciones iniciales de peróxido de hidrógeno (1,8x10 -3 a 4,0x10 -2 mol L -1 ).En los trabajos p...

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“…Kinetics and mechanisms of hydrogen peroxide decomposition in the presence of metal complexes are well described in literature [34]. According to ESR spectroscopy measurements [27] AuNPs generate reactive oxygen species along with formation of hydroxyl radicals at lower and evolution of O 2 at higher pHs.…”

Section: Catalytic Activity Of Zno/pvp-aunps In Decomposition Of Hydrmentioning

confidence: 99%

Catalytic Activity of Gold and Silver Nanoparticles Supported on Zinc Oxide

Yesmurzayeva¹,

Nurakhmetova²,

Tatykhanova³

et al. 2015

Supramolecular Catalysis

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Gold (AuNPs) and silver (AgNPs) nanoparticles have been prepared by “one-pot” synthetic method in the presence of poly(N-vinylpyrrolidone) (PVP). Absorption spectra, size, morphology, and structure of AuNPs and AgNPs were studied by UV-Vis spectroscopy, DLS, SEM, and TEM. According to DLS measurements the average sizes of metal nanoparticles stabilized by PVP in aqueous solution are varied from 10 to 25 nm for AuNPs and from 6.5 to 44 nm for AgNPs. The impregnation method is used to support AuNPs and AgNPs on the surface of ZnO. The amount of AuNPs and AgNPs immobilized on the surface of ZnO does not exceed 0.2 wt.%. The catalytic activity of AuNPs and AgNPs supported on the surface of ZnO was evaluated with respect to decomposition of hydrogen peroxide. The optimal conditions for H2O2 decomposition were found to be dependent on of the amount of the catalyst, concentration of substrate, molecular weight of PVP, and temperature. The activation energy of H2O2 decomposition is equal to 44.1 kJ×mol-1. The decomposition of H2O2 in the presence of AuNPs and AgNPs supported on ZnO surface is discussed in the context of supramolecular catalysis mimicking catalase-like behavior. The recyclability of AuNPs supported on ZnO surface was tested.

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Kinetics and mechanisms of decomposition reaction of hydrogen peroxide in presence of metal complexes

Cited by 122 publications

References 157 publications

New Insights on the Oxidation of Unsaturated Fatty Acid Methyl Esters Catalyzed by Niobium(V) Oxide. A Study of the Catalyst Surface Reactivity

New Insights on the Oxidation of Unsaturated Fatty Acid Methyl Esters Catalyzed by Niobium(V) Oxide. A Study of the Catalyst Surface Reactivity

Estudio cinético de la descomposición catalizada de peróxido de hidrógeno sobre carbón activado

Catalytic Activity of Gold and Silver Nanoparticles Supported on Zinc Oxide

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