scholarly journals Iron-Catalyzed Oxidation of 1-Phenylethanol and Glycerol With Hydrogen Peroxide in Water Medium: Effect of the Nitrogen Ligand on Catalytic Activity and Selectivity

2020 ◽  
Vol 8 ◽  
Author(s):  
Dimitri Ros ◽  
Teresa Gianferrara ◽  
Corrado Crotti ◽  
Erica Farnetti
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Medium Effect ◽  
Water Medium ◽  
Nitrogen Ligand ◽  
Catalyzed Oxidation

Remediation of model wastewater polluted with methyl parathion by reverse micelle entrapped peroxidase

2011 ◽  
Vol 46 (4) ◽  
pp. 345-354
Author(s):  
Zoheb Karim ◽  
Qayyum Husain ◽  
Rohana Adnan ◽  
Naseem Akhtar
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Reverse Micelle ◽  
Oxidation Reaction ◽  
Methyl Parathion ◽  
Catalytic Performance ◽  
Redox Mediators ◽  
Ph Dependency ◽  
Effects Of Ph ◽  
Catalyzed Oxidation

The peroxidase/reverse micelle (RM) system effectively catalyzed the oxidation reaction in cyclohexane, while peroxidase from bitter gourd in aqueous buffer exhibited low catalytic activity. The oxidation of methyl parathion (MPT) has been optimized with effects of pH in the water pools, concentration of peroxidase and degree of surfactant hydration (Wo). The peroxidase/RM system showed a strong pH dependency. Its optimum catalytic activity was obtained when the peroxidase/RM was prepared in a buffer of pH 3.0. The effect of different redox mediators on the peroxidase-catalyzed oxidation of MPT was investigated. MPT was slowly oxidized by the peroxidase/RM system while the addition of phenol as a redox mediator strongly enhanced the catalytic performance of the peroxidase/RM system. Hydrogen peroxide strongly inhibited the activity of peroxidase; when the H2O2 was present at more than 0.80 mM, the MPT transformation was significantly reduced.

Decomposition of hydrogen peroxide on a two-component NiO-CdO catalyst and the effect of ionizing radiation on its catalytic properties

1979 ◽  
Vol 44 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Viliam Múčka
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Nickel Oxide ◽  
Catalytic Properties ◽  
Cadmium Oxide ◽  
Chemisorb Oxygen ◽  
Composition Region ◽  
Chemisorbed Oxygen ◽  
Two Component

The catalytic properties of two-component catalyst nickel oxide-cadmium oxide with the proportions of the components covering the whole composition region 0-100% were examined by studying the decomposition of hydrogen peroxide in aqueous solution on it. In the range 0-25 mol.% CdO, cadmium oxide is found to affect infavourably the ability of nickel oxide to chemisorb oxygen. The amount of the chemisorbed oxygen increases several times on gamma irradiation of the samples. The effect of cadmium oxide on the catalytic activity of the system shows up in fresh samples only indirectly via the changed amount of the oxygen chemisorbed. In older samples the initial catalytic activity of the system is changed, which can be explained based on the concept of bivalent catalytic centres in terms of the co-action of the catalytic centres of the two oxides, which are in equilibrium. The irradiation of the system under study speeds up the processes leading to the establishing of this equilibrium which is thermally very stable, and results in a substantial increase of the catalytic activity of the samples investigated.

Hydrogen peroxide decomposition on a two-component CuO-Cr2O3 catalyst

1988 ◽  
Vol 53 (8) ◽  
pp. 1636-1646 ◽  
Author(s):  
Viliam Múčka ◽  
Kamil Lang
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Extreme Values ◽  
Catalytic Properties ◽  
Active Components ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Peroxide Decomposition ◽  
Two Component ◽  
Catalytically Active

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.

scholarly journals Metal-catalyzed oxidation renders silver intensification selective. Applications for the histochemistry of diaminobenzidine and neurofibrillary changes.

1986 ◽  
Vol 34 (12) ◽  
pp. 1667-1672 ◽  
Author(s):  
F Gallyas ◽  
J R Wolff
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Polymerization ◽  
Silver Coating ◽  
Neurofibrillary Changes ◽  
Iodide Ions ◽  
Tissue Sections ◽  
Metal Catalyzed Oxidation ◽  
Pre Treatment ◽  
Metal Catalyzed ◽  
Catalyzed Oxidation

Physical developers can increase the visibility of end products of certain histochemical reactions, such as oxidative polymerization of diaminobenzidine and selective binding of complex silver iodide ions to Alzheimer's neurofibrillary changes. Unfortunately, this intensification by silver coating is generally superimposed on a nonspecific staining originating from the argyrophil III reaction, which also takes place when tissue sections are treated with physical developers. The present study reveals that the argyrophil III reaction can be suppressed when tissue sections are treated with certain metal ions and hydrogen peroxide before they are transferred to the physical developer. The selective intensification of Alzheimer's neurofibrillary changes requires a pre-treatment with lanthanum nitrate (10 mM/liter) and 3% hydrogen peroxide for 1 hr. The diaminobenzidine reaction can be selectively intensified when physical development is preceded by consecutive treatments with copper sulfate (10 mM/liter, pH 5, 10 min) and hydrogen peroxide (3%, pH 7, 10 min). In peroxidase histochemistry, this high-grade intensification may help to increase specificity and reduce the threshold of detectability in tracing neurons with horseradish peroxidase or in immunohistochemistry when the peroxidase-antiperoxidase method is used.

ChemInform Abstract: Sulfonic Acid Resin-Catalyzed Oxidation of Aldehydes to Carboxylic Acids by Hydrogen Peroxide.

ChemInform ◽  
2013 ◽  
Vol 44 (29) ◽  
pp. no-no
Author(s):  
Xiaomei Yang ◽  
Si Tang ◽  
Tianliang Lu ◽  
Chen Chen ◽  
Lipeng Zhou ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Carboxylic Acids ◽  
Sulfonic Acid ◽  
Acid Resin ◽  
Catalyzed Oxidation ◽  
Sulfonic Acid Resin

scholarly journals The utilization of the mesoporous Ti-SBA-15 catalyst in the epoxidation of allyl alcohol to glycidol and diglycidyl ether in the water medium

2015 ◽  
Vol 17 (4) ◽  
pp. 23-31 ◽  
Author(s):  
Agnieszka Wróblewska ◽  
Edyta Makuch ◽  
Małgorzata Dzięcioł ◽  
Roman Jędrzejewski ◽  
Paweł Kochmański ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Allyl Alcohol ◽  
Water Solution ◽  
Reaction Medium ◽  
Diglycidyl Ether ◽  
Molar Ratio ◽  
Water Medium ◽  
Catalyst Content ◽  
Allyl Alcohol Epoxidation

Abstract This work presents the studies on the optimization the process of allyl alcohol epoxidation over the Ti-SBA-15 catalyst. The optimization was carried out in an aqueous medium, wherein water was introduced into the reaction medium with an oxidizing agent (30 wt% aqueous solution of hydrogen peroxide) and it was formed in the reaction medium during the processes. The main investigated technological parameters were: the temperature, the molar ratio of allyl alcohol/hydrogen peroxide, the catalyst content and the reaction time. The main functions the process were: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, the selectivity of transformation to diglycidyl ether in relation to allyl alcohol consumed, the conversion of allyl alcohol and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The analysis of the layer drawings showed that in water solution it is best to conduct allyl alcohol epoxidation in direction of glycidol (selectivity of glycidol 54 mol%) at: the temperature of 10–17°C, the molar ratio of reactants 0.5–1.9, the catalyst content 2.9–4.0 wt%, the reaction time 2.7–3.0 h and in direction of diglycidyl ether (selectivity of diglycidyl ether 16 mol%) at: the temperature of 18–33°C, the molar ratio of reactants 0.9–1.65, the catalyst content 2.0–3.4 wt%, the reaction time 1.7–2.6 h. The presented method allows to obtain two very valuable intermediates for the organic industry.

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