Oxidation of some aliphatic polyols on anodically deposited MnO2

Das, Debasmita; Samaddar, Purabi Rani; Sen, Pratik; Das, Kaushik

doi:10.1007/s10800-008-9503-9

Cited by 12 publications

(9 citation statements)

References 22 publications

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“…The respective systems offer a large variety of oxidation states, the potential for mixed electronic/ionic conduction, and the possibility of generation of highly functionalized oxy-species. For example, the importance of formation of multiple hydroxyl groups within an anodically generated MnO 2 layer deposited on Pt was demonstrated during the electrocatalytic oxidation of alcohols in neutral media [27]. It was suggested that successive generation and consumption of a Mn(V) species is a crucial factor in the overall reaction mechanism.…”

Section: Application Of Metal Oxides As Active Matricesmentioning

confidence: 99%

“…It was characterized by considering the generation of a reactive Mn species with an oxidation state greater than IV, some of which undergo disproportionation to oxidation state V that is believed to be an important intermediate that is reactive toward alcohols [27,79]. This concept can be extended to the electrooxidation carbohydrates [27,79]. …”

Section: Application Of Metal Oxides As Active Matricesmentioning

confidence: 99%

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Electrocatalytic oxidation of small organic molecules in acid medium: Enhancement of activity of noble metal nanoparticles and their alloys by supporting or modifying them with metal oxides

Kulesza

Pieta

Rutkowska

et al. 2013

Electrochimica Acta

107

114

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Different approaches to enhancement of electrocatalytic activity of noble metal nanoparticles during oxidation of small organic molecules (namely potential fuels for low-temperature fuel cells such as methanol, ethanol and formic acid) are described. A physical approach to the increase of activity of catalytic nanoparticles (e.g. platinum or palladium) involves nanostructuring to obtain highly dispersed systems of high surface area. Recently, the feasibility of enhancing activity of noble metal systems through the formation of bimetallic (e.g. PtRu, PtSn, and PdAu) or even more complex (e.g. PtRuW, PtRuSn) alloys has been demonstrated. In addition to possible changes in the electronic properties of alloys, specific interactions between metals as well as chemical reactivity of the added components have been postulated. We address and emphasize here the possibility of utilization of noble metal and alloyed nanoparticles supported on robust but reactive high surface area metal oxides (e.g. WO3, MoO3, TiO2, ZrO2, V2O5, and CeO2) in oxidative electrocatalysis. This paper concerns the way in which certain inorganic oxides and oxo species can act effectively as supports for noble metal nanoparticles or their alloys during electrocatalytic oxidation of hydrogen and representative organic fuels. Among important issues are possible changes in the morphology and dispersion, as well as specific interactions leading to the improved chemisorptive and catalytic properties in addition to the feasibility of long time operation of the discussed systems.

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Section: Application Of Metal Oxides As Active Matricesmentioning

confidence: 99%

Section: Application Of Metal Oxides As Active Matricesmentioning

confidence: 99%

Electrocatalytic oxidation of small organic molecules in acid medium: Enhancement of activity of noble metal nanoparticles and their alloys by supporting or modifying them with metal oxides

Kulesza

Pieta

Rutkowska

et al. 2013

Electrochimica Acta

107

114

View full text Add to dashboard Cite

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“…Notably, MnO 2 is an electrocatalyst for carbohydrate oxidation. Das et al (2008) asserted that anodically deposited MnO 2 from the electrolysis of MnSO 4 could oxidize aliphatic alcohols through successive generation and consumption of Mn(V) species. 32 The changes in pH (from an initial value of 3) during electrolysis (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Das et al (2008) asserted that anodically deposited MnO 2 from the electrolysis of MnSO 4 could oxidize aliphatic alcohols through successive generation and consumption of Mn(V) species. 32 The changes in pH (from an initial value of 3) during electrolysis (Fig. 2b) indicates that pH increases obviously after 60 min by using magnesium and sodium chloride, and almost reaches unity by using manganese chloride in 2 h. In simple Cl − electrolysis (without organic acid), the full reaction generates HOCl at the anode and hydrogen gas and hydroxyl ions at the cathode, which would cause pH to increase:…”

Section: Resultsmentioning

confidence: 99%

Electrochemical Oxidation of Carboxylic Acids in the Presence of Manganese Chloride

Shih

Cheng

Ariyanto

et al. 2013

J. Electrochem. Soc.

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Carboxylic acids are the main byproducts in effluents after treating source pollutants with advanced oxidation processes (AOPs). This work developed a feasible electrochemical method for mineralizing oxalic acid and citric acid (50 ppm, pH i = 3). A reactor was mounted with RuO 2 /IrO 2 coated Ti-DSA electrodes (titanium dimensional stable anode). The selected chloride electrolytes (NaCl, MgCl 2 and MnCl 2 , [Cl − ] = 20 mM) mineralized completely oxalic acid through the production of active chlorine. However, the highest total organic carbon (TOC) removal efficiency was obtained using MnCl 2 and was aided by the MnO 2 deposited electrochemically on the anode. In the chlorine-free electrolysis process, the performance in terms of TOC removal of the Ti-DSA electrodes that had MnO 2 on the anode depended on the electrical conditions. Without electricity, MnO 2 directly mineralized oxalic acid; with electricity, TOC removal from the citric acid solution improved substantially. The changes in the Mn 2+ concentration suggest that MnO 2 dissolved by organic compounds could be recovered and reused through formation of electrolytic manganese dioxide (EMD).In recent years, advanced oxidation processes (AOPs) have been applied to remove hazardous and environmentally undesirable chemicals from industrial wastewater. Among AOPs, the Fenton technique, which has many merits, such as cost effectiveness and simple operation, can efficiently generate hydroxyl radicals by catalyzing hydrogen peroxide with ferrous ions. However, the high reaction constant (k = 4.3 × 10 9 L mol −1 s −1 ) between the hydroxyl radical and chloride ion, which is a co-existing ion in Fenton chemicals (also frequently in wastewater), typically prohibits the hydroxyl radical from mineralizing the intermediates that are from the oxidation of target aromatic compounds. 1 These intermediates are generally carboxylic acids, and are the major parts of total organic carbon (TOC) residues in end waters from a Fenton process (oxalic acid and citric acid reacting with hydroxyl radicals have reaction constants of 1.4 × 10 6 and 5 × 10 7 L mol −1 s −1 , respectively). 2 Although the photo-or electrical assistance can extend the life span of hydroxyl radicals to improve the mineralization of intermediates. 3-5 Biodegradation has been used in the treatment of carboxylic acids in oil sand process water. 6 However, the costs of sludge disposal and reagents in present methods still have to be reduced. Carboxylic acids are known as agriculturally inhibitors of crops, and accumulates in natural soils during manure followed by water logging. The phytotoxicity of carboxylic acids may potentially cause another environmental problems after the Fenton oxidation of aromatic pollutants. 7 Direct and indirect electrochemical oxidation of organic substances is extensively exploited to overcome the scavenging effect of chloride ions in Fenton reactions. [8][9][10] In the presence of chloride ions, electrochemical chlorine is produced by anodic oxidation, and hydrogen is generated at...

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“…It is considered that Pb 2+ and Mn 2+ cations are oxidized at high anodic applied potential due to interaction mainly with adsorbed OH-radicals, produced by the water-splitting reaction [19,20]. The overall process of oxidation of Pb 2+ and Mn 2+ cations is presented schematically as follows:…”

Section: Introductionmentioning

confidence: 99%

Express-method for Estimation of Electrocatalytic Activity of Oxide Films toward Oxygen Transfer Reactions

Poltavets¹,

Vargalyuk²,

Shevchenko³

2018

ujc

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Oxidation catalysis of organic substances has attracted special attention in recent years due to of their high industrial significance in green and energy chemistry. The implementation of a transition metal-based catalyst in combination with oxygen is an alternative to the traditional procedures. This study justifies the application of amperometric response 'in situ' for estimation of the electrocatalytic activity of metal oxide films, which are known to be promising for oxygen transfer processes. The reaction of electrooxidation of Mn 2+ ions may be termed as a 'marker' for oxygen transfer reactions due to its kinetic features, such as proportionality between the current density and the surface concentration of •OH-radicals. The relative parameter, k ox , has been offered for estimation of the oxidizing capacity of an anode material toward oxygen transfer reaction in reference to platinum oxidizing capacity. k ox value is automatically calculated exactly during electroplating of MnO x as a ratio of the current density of Mn 2+ + 2H 2 O-2e→MnO 2 +4H + reaction on the tested surface to the current density of this reaction on Pt surface. The developed method was tested during the investigation of catalytic activity of MnO x films for electrooxidation of glucose. The parameter k ox was calculated for other anode materials and was analyzed. The application of the new method allows estimating and comparing the catalytic performance toward oxygen transfer reactions of anode materials or of the same material in different modifications, such as nano particles, composites, different compositions etc. The pre-test reduces manifold the time spent for determination of oxidizing capacity of oxides.

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Oxidation of some aliphatic polyols on anodically deposited MnO2

Cited by 12 publications

References 22 publications

Electrocatalytic oxidation of small organic molecules in acid medium: Enhancement of activity of noble metal nanoparticles and their alloys by supporting or modifying them with metal oxides

Electrocatalytic oxidation of small organic molecules in acid medium: Enhancement of activity of noble metal nanoparticles and their alloys by supporting or modifying them with metal oxides

Electrochemical Oxidation of Carboxylic Acids in the Presence of Manganese Chloride

Express-method for Estimation of Electrocatalytic Activity of Oxide Films toward Oxygen Transfer Reactions

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