Catalytic Decomposition Of Hydrogen Peroxide Research Articles

Perovskite La1−xSrxFe1−yMnyO3 hollow nanospheres: Synthesis and application in catalytic hydrogen peroxide decomposition

Perovskite-type LaFeO3 and La1−xSrxFe1−yMnyO3 hollow nanospheres were prepared, for the first time, via a urea-assisted one-pot solvothermal method. The chemical compositions, crystalline phases, specific surface areas and morphologies of the materials as-prepared were characterized by ICP-OES, XRD, nitrogen adsorption and TEM, respectively. It was found that the presence of urea greatly decreased the nucleation temperature which led to the smaller particle sizes of products. As a potential application, the materials as-prepared exhibited superior activity and good stability in the catalytic decomposition of hydrogen peroxide. The excellent activity of La1−xSrxFe1−yMnyO3 hollow nanospheres can be rationalized by their high specific surface areas and hollow nanoparticle morphology. The high stability of these materials can be attributed to their perovskite-type crystal structures.

Energy Diagram for the Catalytic Decomposition of Hydrogen Peroxide

Drawing a schematic energy diagram for the decomposition of H2O2 catalyzed by MnO2 through a simple thermometric measurement outlined in this study is intended to integrate students’ understanding of thermochemistry and kinetics of chemical reactions. The reaction enthalpy, ΔrH, is determined by a conventional thermometric method, where a modified calorimetric vessel with negligible thermal leakage is used. Thermometric curves for the reactions at different initial temperatures can be converted to different series of kinetic rate data under nonlinearly changing temperatures. The apparent activation energy, Ea, is easily determined by the differential kinetic relationship at the fixed degree of reaction among the different series of kinetic rate data. By determination of both ΔrH and Ea, students can draw a schematic diagram of the energy change accompanying the reaction. The laboratory activity and post lab data treatments are useful in general chemistry courses at the university or college level and also applicable in advanced chemistry courses in high schools.

The use of cyclic voltammetry to assess the activity of carbon materials for hydrogen peroxide decomposition

It is known that carbon materials catalyze hydrogen peroxide decomposition in aqueous media. However, the catalytic activity of a particular carbon is dependent on various coupled structural, textural and chemical characteristics of the material, such that, formerly, the prediction of activity has not been possible. Here, the application of cyclic voltammetry (CV) is introduced as a rapid and conclusive technique in this respect. Three classes of carbon materials have been investigated: activated carbons, carbon blacks, and graphites, including some selected acid-washed samples which were used to examine the roles of mineral matter and surface oxygen. Characterization by electrochemical capacity measurements with CV, together with catalytic activity tests for hydrogen peroxide decomposition, reveal that the exchange current is directly proportional to the catalytic activity for hydrogen peroxide decomposition. That is, a linear dependence was found between this variable and the apparent first order catalytic decomposition rate constant. CV measurements with modified carbons also allow the elucidation of the effects of physicochemical characteristics of carbon materials on the rate of hydrogen peroxide decomposition.

In Vitro Oxidative Damage Induced in Livers, Hearts and Kidneys of Rat Treated with Water Extract (Leachate) from Municipal Battery Recycling Site: Evidence as Environmental Pollution and Tissue Damage

Abstract The health effects of the Municipal Auto-Battery Dust Leachate (MABDL) and Elewi Odo Municipal Auto- Battery Recycling Site Leachate (EOMABRL) on levels of Thiobarbituric Acid Reactive Substances (TBARS) were investigated in livers, kidneys and hearts of male albino rat-in vitro. The two varieties of leachates significantly (p<0.05) increased MDA level in the liver, kidney and heart in a dose-dependent manner with Municipal Auto-Battery Dust Leachate (MABDL) having stronger induction ability than Elewi Odo Municipal Auto-Battery Recycling Site Leachate (EOMABRL). MDA levels of EOMABRL were significantly (p<0.05) elevated in the liver, kidney and heart by 55.56%, 41.3% and 39.13% respectively compared to the corresponding control at the highest dose. Similarly, MDA contents of MABDL were significantly (p<0.05) elevated in the kidney, heart and liver by 195.65%, 115.2% and 83.33% respectively compared to the corresponding control at the highest dose. However, the liver is highly sensitive to EOMABRL exposure than kidney and heart. In contrast, the kidney is more susceptible to MABDL exposure than heart and liver. Collectively, the possible mechanisms by which varieties of battery leachates exert nephritis, hepatitis and cardiovascular malfunctioning is through high induction of lipid peroxidation and heavy metal (Cu2+ ,Fe2+ ,Pb2+ etc) catalyzed hydrogen peroxide decomposition to produced OH• via Fenton reaction.

Effect of ultrasonic pre-treatment of thermomechanical pulp on hydrogen peroxide bleaching

Ultrasound pre-treatments of softwood TMP had been carried to evaluate its impact on the efficiency of hydrogen peroxide bleaching. The trials were performed after a factorial design of experiment using frequency, power and time as variables. The experiments were conducted in an ultrasonic bath and then bleached with hydrogen peroxide. Measurements such as brightness, L*A*B* color system coordinate, residual hydrogen peroxide and metal content were evaluated on bleached pulp. The results indicate that the effect of ultrasonic treatment on brightness was dependent on the ultrasound frequency used; the brightness increased slightly at 68 kHz and decreased at 40 and 170 kHz. These results were correlated to the ultrasound effect on the generation of transition metals (copper, iron and manganese) which are responsible for catalytic decomposition of hydrogen peroxide. The influence of metal interference was minimized by using a chelating agent such as diethylene triamine pentaacetic acid (DTPA). With the results obtained in this study we have identified a set of option conditions, e.g. 1000 W, 40 kHz, 1.5 % consistency and 0.2% addition of DTPA prior to the bleaching stage (after ultrasonic pre-treatment) who improve brightness by 2.5 %ISO.

On the Limitation of Fenton Oxidation Operational Parameters: A Review

Abstract The literature on the use of Fenton oxidation in wastewater treatment has established the method as one of the most effective and suitable methods for recalcitrant wastewater treatment. It is an advanced oxidation process (AOP) that utilises the highly reactive hydroxyl radical (•OH) to aggressively and non-selectively destroy organic contaminants. The Fenton oxidation possesses environmental and economic benefits coupled with effective mineralisation of most wastewater organics. Broadly, the Fenton oxidation encompasses three types of oxidation routes for the production of •OH: (i) through the use of Fenton reagents alone, termed classical Fenton oxidation (CFO), (ii) assisted by means of UV (photo-Fenton), or (iii) electron beams (electro-Fenton). However, this review is limited to CFO, which involves the catalytic decomposition of hydrogen peroxide (H2O2) by suitable transition metals to generate •OH. Despite the many advantages of the CFO process, there are issues related to operational parameters and the final treated wastewater, the most notable being pH modulation, the presence of the catalyst and the cost of the oxidant (H2O2). Furthermore, sludge generation constitutes an apparent drawback to the utilisation of this technology. This paper attempts to review the highlighted limitations and presents researches and advances reported in the literature addressing these issues.

Asymmetric Hybrid Silica Nanomotors for Capture and Cargo Transport: Towards a Novel Motion‐Based DNA Sensor

An innovative self-propelled nanodevice able to perform motion, cargo transport, and target recognition is presented. The system is based on a mesoporous motor particle, which is asymmetrically functionalized by the attachment of single-stranded DNA onto one of its faces, while catalase is immobilized on the other face. This enzyme allows catalytic decomposition of hydrogen peroxide to oxygen and water, giving rise to the driving force for the motion of the whole system. Moreover the motor particles are able to capture and transport cargo particles functionalized with a noncomplementary single-stranded DNA molecule, only if a specific oligonucleotide sequence is present in the media. Functionalization with characteristic oligonucleotide sequences in the system implies a potential for further developments for lab-on-chip devices with applications in biomedical applications.

Use of EIS to Measure the Rate of H2O2 Decomposition on a Bulk Magnetite Electrode in Alkaline Solution

The new generation of supercritical cooled water reactors (SCWR) are susceptible to particulate fouling as a result of corrosion product sedimentation. Iron oxides are a major component of corrosion products and are also known to catalyze hydrogen peroxide decomposition. This work aimed to investigate the rate of H2O2 decomposition on the surface of a magnetite bulk electrode by using electrochemical impedance spectroscopy. A magnetite bulk electrode was immersed in a suspension of various concentrations of magnetite particles and initial H2O2 concentration of 10−2 M. It was observed that the electrochemical response of the magnetite surface (which is partially oxidized to γ − Fe+3 species) is a function of H2O2 concentration. Therefore, at different time intervals EIS was used to obtain charge transfer resistance as a proxy variable for hydrogen peroxide concentration. These measurements were compared to results obtained by permanganate titration. It was observed that the changes of decomposition current density extracted from the EIS data fitting process for various conditions were in good agreement with the titration results. H2O2 decomposition in the presence of iron oxide particles was found to be a second-order reaction with rate constants of 0.015 and 0.017 min−1g−1L (obtained from EIS and titration methods, respectively).

Importance of Iron Chelation in Free Radical-Induced Oxidative Stress and Human Disease

Iron is a redox active metal involved in the oxidation-reduction reactions and regulation of cell growth and differentiation. Iron is an integral part of many proteins and enzymes that maintains various physiological functions. Most of the human body's iron is contained in red blood cells. Despite iron being an abundant trace metal in food, millions of people worldwide suffer from anemia. Iron deficiency results in impaired production of iron-containing proteins and inhibition of cell growth. In contrast, abnormal iron uptake has been related to the most common hereditary disease hemochromatosis, leading to tissue damage derived from free radical toxicity. In addition, disruption of iron regulation plays a key role in the etiology of Alzheimer's disease, Parkinson's disease, Huntington's disease, Friedreich's ataxia and other neurological disorders, cancer (lung cancer, breast cancer, colon cancer), Fanconi anemia, stroke and ageing. Thus the control of this necessary but potentially toxic substance is an important part of many aspects of human health and disease. The most frequent is the toxic role of iron linked with the catalytic decomposition of hydrogen peroxide (Fenton reaction) leading to the formation of reactive oxygen species (ROS) causing damage to biomolecules, including lipids, proteins and DNA. The binding of iron-designed chelators via nitrogen, oxygen or sulphur donor atoms blocks iron s ability to catalyze the formation of free radicals. Thus the design of various metal chelators to prevent free radical reactions is an important approach in the treatment of many iron-related diseases. The development of effective dual functioning antioxidants, possessing both metal-chelating and free radical-scavenging properties is awaited. The aim of this review is to discuss the role of iron and importance of iron-chelation in human disease and ageing.

New insight on kinetics of catalytic decomposition of hydrogen peroxide on ferrihydrite: Based on the preparation procedures of ferrihydrite

The heterogeneous catalytic reaction of H 2O 2 with iron oxides is an important reaction for the environment since both H 2O 2 and iron oxides are common constituents of natural and atmospheric waters. In this work, three ferrihydrites, labeled Fh-1, -2 and -3, were prepared by different procedures. Fh-1 was prepared by adding alkali solution to ferric solution under stirring. In the preparation of Fh-2, the mixing procedure of the two solutions was reversed. Fh-3 was obtained by adding alkali solution and ferric solution simultaneously into a certain amount of water. The heterogeneous catalytic reaction of H 2O 2 with three ferrihydrites in aqueous solution was investigated in detail. The results demonstrated that the apparent reaction rate was affected by the preparation procedure of ferrihydrite besides pH, temperature and the dose of catalyst. The activation energy of the decomposition reaction of H 2O 2 was determined to be 76.13, 59.41 and 68.05 kJ mol −1 for Fh-1, -2 and -3, respectively. The activation enthalpy of the reaction were determined to be 73.59, 56.56 and 65.76 kJ mol -1 and the activation entropy of the reaction were determined to be −69.65, −119.67 and −90.58 J mol −1 K −1, respectively.

Effect of some parameters on the rate of the catalysed decomposition of hydrogen peroxide by iron(III)-nitrilotriacetate in water

The decomposition rate of H 2O 2 by iron(III)-nitrilotriacetate complexes (Fe IIINTA) has been investigated over a large range of experimental conditions: 3 < pH < 11, [Fe(III)] T,0: 0.05–1 mM; [NTA] T,0/[Fe(III)] T,0 molar ratios : 1–250; [H 2O 2] 0: 1 mM–4 M) and concentrations of HO radical scavengers: 0–53 mM. Spectrophotometric analyses revealed that reactions of H 2O 2 with Fe IIINTA (1 mM) at neutral pH immediately lead to the formation of intermediates (presumably peroxocomplexes of Fe IIINTA) which absorb light in the region 350–600 nm where Fe IIINTA and H 2O 2 do not absorb. Kinetic experiments showed that the decomposition rates of H 2O 2 were first-order with respect to H 2O 2 and that the apparent first-order rate constants were found to be proportional to the total concentration of Fe IIINTA complexes, were at a maximum at pH 7.95 ± 0.10 and depend on the [NTA] T,0/[Fe(III)] T,0 and [H 2O 2] 0/[Fe(III)] T,0 molar ratios. The addition of increasing concentrations of tert-butanol or sodium bicarbonate significantly decreased the decomposition rate of H 2O 2, suggesting the involvement of HO radicals in the decomposition of H 2O 2. The decomposition of H 2O 2 by Fe IIINTA at neutral pH was accompanied by a production of dioxygen and by the oxidation of NTA. The degradation of the organic ligand during the course of the reaction led to a progressive decomplexation of Fe IIINTA followed by a subsequent precipitation of iron(III) oxyhydroxides and by a significant decrease in the catalytic activity of Fe(III) species for the decomposition of H 2O 2.

Influence of the structural and surface characteristics of activated carbon on the catalytic decomposition of hydrogen peroxide

Hydrogen peroxide decomposition has been studied with three activated carbons before and after different modifications upon HCl lixiviation, oxidation with HNO 3 and heat treatment in inert atmosphere. The surface of activated carbon promotes H 2O 2 decomposition to an extent depending on related-structural features and the amount and nature of surface oxygen groups. A lower ordering of the carbon structure with less developed graphene layers leads to a higher decomposition rate due to a higher surface concentration of unpaired electron active sites. In activated carbons with a similar structural ordering, the presence of acidic surface oxygen groups inhibits the decomposition of hydrogen peroxide. Taking into account these two phenomena, empirical equations based on the most reactive carbon fraction by TPO, defects aliphatic carbon fraction, assessed by XPS, and the content of surface oxygen groups, determined by TPD, have been developed for describing the hydrogen peroxide decomposition ability of activated carbons.

Straightforward single-step generation of microswimmers by bipolar electrochemistry

Autonomous microswimmers are of enormous interest not only from an academic point of view, but also for future practical applications ranging from miniaturized motors to nanomedicine. A key step for the generation of such objects is their dissymmetric modification with a catalyst particle that activates the chemical conversion of a fuel molecule, leading ultimately to the propulsion of the object. So far it has been quite difficult to synthesize such dissymmetric objects and most approaches are based on using interfaces to break the symmetry. We demonstrate here that a very simple approach based on bipolar electrochemistry allows the bulk generation of carbon microtubes that are modified selectively at one end with a Pt cluster. The presence of this metal cluster allows the catalytic decomposition of hydrogen peroxide and the resulting oxygen bubbles trigger the propulsion of the object. The type of motion can be switched from linear to circular as a function of the exact position of the Pt cluster.

Dynamics of catalytic tubular microjet engines: Dependence on geometry and chemical environment

Strain-engineered tubular microjet engines with various geometric dimensions hold interesting autonomous motions in an aqueous fuel solution when propelled by catalytic decomposition of hydrogen peroxide to oxygen and water. The catalytically-generated oxygen bubbles expelled from microtubular cavities propel the microjet step by step in discrete increments. We focus on the dynamics of our tubular microjets in one step and build up a body deformation model to elucidate the interaction between tubular microjets and the bubbles they produce. The average microjet velocity is calculated analytically based on our model and the obtained results demonstrate that the velocity of the microjet increases linearly with the concentration of hydrogen peroxide. The geometric dimensions of the microjet, such as length and radius, also influence its dynamic characteristics significantly. A close consistency between experimental and calculated results is achieved despite a small deviation due to the existence of an approximation in the model. The results presented in this work improve our understanding regarding catalytic motions of tubular microjets and demonstrate the controllability of the microjet which may have potential applications in drug delivery and biology.

Quantitative determination of some water-soluble B vitamins by kinetic analytical method based on the perturbation of an oscillatory reaction

A novel procedure for kinetic determination of some water-soluble vitamins of the B-group (thiamine (B1), riboflavin (B2), niacin (B3) and pyridoxine (B6)) by the concentration perturbations of the Bray-Liebhafsky (BL) oscillatory chemical system involving the catalytic decomposition of hydrogen peroxide in the presence of both hydrogen and iodate ions is proposed and validated. The method uses a Pt electrode for potentiometric monitoring of the concentration perturbations of the BL matrix in a stable non-equilibrium stationary state close to the bifurcation point. The proposed method relies on the linear relationship between maximal potential displacements, ΔEm, caused by the additional known quantities of a B species. Under the optimal established analytical conditions, linear calibration curves were obtained over the range of 0.01-1.0, 0.016-0.128, 5.0-50.0 and 0.05-2.5 μmol with the limits of detection of 0.01, 0.018, 2.6 and 0.03 μmol, as well as analytical throughput of 30, 5, 12 and 20 determinations per hour, for B1, B2, B3 and B6, respectively. The used technical approach also provides simple, effective and convenient method to assay the pharmaceutical formulations containing B1 together with other active principles such as nicotinamide and vitamin B12 as well as B3.

Decomposition of hydrogen peroxide in the presence of activated carbons with different characteristics

AbstractBACKGROUND: Catalytic ozonation promoted by activated carbon is a promising advanced oxidation process used in water treatment. Hydrogen peroxide generated as a by‐product from the reaction of ozone with some surface groups on the activated carbon or from the oxidation of some organic compounds present in the water being treated seems to play a key role in the catalytic ozonation process. Hydrogen peroxide decomposition promoted by two granular activated carbons (GAC) of different characteristics (Hydraffin P110 and Chemviron SSP‐4) has been studied in a batch reactor. The operating variables investigated were the stirring speed, temperature, pH and particle size. Also, the influence of metals on the GAC surface, that can catalyze hydrogen peroxide decomposition, was observed.RESULTS: Chemviron SSP‐4 showed a higher activity to decompose hydrogen peroxide than HydraffinP110 (70 and 50% of hydrogen peroxide removed after 2 h process, respectively). Regardless of the activated carbon used, hydrogen peroxide decomposition was clearly controlled by the mass transfer, although temperature and pH conditions exerted a remarkable influence on the process. Catalytic ozonation in the presence of activated carbon and hydrogen peroxide greatly improved the mineralization of oxalic acid (a very recalcitrant target compound). About 70% TOC (total organic carbon) depletion was observed after 1 h reaction in this combined system, much higher than the mineralization achieved by the single processes used.CONCLUSIONS: Of the two activated carbons studied, Chemviron SSP‐4 with an acidic nature presented a higher activity to decompose hydrogen peroxide. However the influence of the operating variables was quite similar in both cases. Experiments carried out in the presence of tert‐butanol confirmed the appearance of radical species. A kinetic study indicated that the process was controlled by the internal mass transfer and the chemical reaction on the surface of the activated carbon. The catalytic activity of hydrogen peroxide in oxalic acid ozonation promoted by activated carbon (O3/AC/H2O2) was also studied. The results revealed the synergetic activity of the system O3/AC/H2O2 to remove oxalic acid. Copyright © 2010 Society of Chemical Industry

Synthesis of starch-stabilized silver nanoparticles and their application as a surface plasmon resonance-based sensor of hydrogen peroxide

Stable and uniform starch-stabilized silver nanoparticles with average diameter 14.4 ± 3.3 nm are synthesized via green synthetic procedure, using ultrasound mediated reduction of silver nitrate by d-glucose. UV–vis spectroscopy, high-resolution transmission electron microscopy, X-ray diffraction, thermogravimetric/differential thermal analysis and differential scanning calorimetry are used to completely characterize the starch-stabilized silver nanoparticles. These nanoparticles exhibit a catalytic activity in the reduction of hydrogen peroxide (H 2O 2). The degradation of silver nanoparticles, induced by the catalytic decomposition of hydrogen peroxide, causes a considerable change in the absorbance strength of localized surface plasmon resonance band depending on the H 2O 2 concentration. The characterization and calibration of improvised plasmon resonance-based optical sensor is carried out. A good sensitivity and a linear response over the wide concentration range of 10 −1–10 −6 mol/L H 2O 2 is established. The quantification limit of this sensor is found to be 0.9 μM H 2O 2, which is lower than certain enzyme-based biosensors. Therefore, this optical sensor for hydrogen peroxide can be potentially applied in determination of other reactive oxygen species as well.

Efficient hydrogen peroxide decomposition on bimetallic Pt–Pd surfaces

Abstract Hydrogen peroxide was efficiently decomposed on Pt–Pd surface deposited on Nafion membrane. Comparing the activities for the different materials, the activity for the decomposition of hydrogen peroxide was found to decrease in the order of Pt–Pd surface > MnO 2 > K 2 Cr 2 O 7 > Au > Polycrystalline Pt plate. Kinetics and thermodynamics of the decomposition process were investigated. It was observed that the decomposition process followed bimolecular first order kinetics, which was well fitted with Eley–Rideal (E–R) model. In this paper, the reason of efficient catalytic decomposition of hydrogen peroxide over bi–metallic Pt–Pd surface has been discussed.

Design, fabrication and demonstration of a MEMS steam generator for ejector pump applications

The design, fabrication, successful demonstration and characterization of a microfabricated steam generator based on the homogeneous catalytic decomposition of hydrogen peroxide are presented. The device consists of a mixer, a reactor and a nozzle, and it produces a jet of high-speed steam that can be used for driving ejector pumps and for nanosatellite microthrusters. Numerically implemented coupled chemical, thermal and fluidic modeling was used to design the device, which was then fabricated via bulk micromachining and enclosed in a thermally insulating package. The device operated successfully with 90% peroxide catalyzed by a ferrous chloride tetrahydrate solution. Refractive index analysis is used to confirm full peroxide decomposition, and visual inspection and temperature measurements are used to confirm full water vaporization. The experimental results are analyzed to provide comprehensive model verification.

ChemInform Abstract: Oscillatory Kinetics and Mechanism of the Chromate Catalyzed Decomposition of Hydrogen Peroxide.

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