Hydrothermal MnO2: synthesis, structure, morphology and discharge performance

Walanda, Daud K.; Lawrance, Geoffrey A.; Donne, Scott W.

doi:10.1016/j.jpowsour.2004.06.062

Cited by 98 publications

(72 citation statements)

References 23 publications

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“…4c) shows dispersed needle-like crystallites, but with a larger average diameter of 11 nm. It is evident that the degree of dispersion for the prepared cryptomelane particles on using either acetate and or sulphate is higher than that on using chloride, in agreement with Walanda et al's [25] study.…”

Section: Transmission Electron Microscopy (Tem)supporting

confidence: 89%

Preparation of nano-structured cryptomelane materials for catalytic oxidation reactions

et al. 2016

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Manganese-based octahedral molecular sieves of the type K-OMS-2 (cryptomelane structure) were prepared via reflux method by synproportionation of KMnO 4 and Mn 2? in acidic aqueous suspension. For this method, different manganese anions (sulphate, chloride and acetate) were used, which exert a strong influence on the prepared materials. Several techniques such as X-ray diffraction, Fourier transformer infrared, Raman spectroscopy, transmission electron microscopy, differential and gravimetric thermal analysis and H 2 -temperature programmed reduction were used to characterize the prepared samples. The results revealed that the prepared samples were mainly pure mono-phase cryptomelane materials. The obtained K-OMS-2 material on using the sulphate anion has more available lattice oxygen as compared to that prepared by the other anions. The catalytic activity of the prepared samples was tested towards the oxidative dehydrogenation of cyclohexane. Over the K-OMS-2RS sample, cyclohexane conversion was significantly higher than the other prepared samples.

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Section: Transmission Electron Microscopy (Tem)supporting

confidence: 89%

Preparation of nano-structured cryptomelane materials for catalytic oxidation reactions

et al. 2016

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“…Electrodeposition of manganese dioxide from acidic aqueous solution is believed to be affected essentially by the following successive steps. 23,28,29) Mn sol 2þ ! Mn ads…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, the lifetime of soluble Mn 3þ intermediate species (i.e., [Mn(H 2 O) 6 ] 3þ ) is increased with the increase in the acidity of deposition electrolytes. 28,29) This may put a greater dependence on disproportionation route, i.e. reaction (11), to form Mn-Mo-W oxide deposits and lead to a decrease in Mn 3þ content in oxide deposit with the decrease in the pH of deposition electrolyte.…”

Section: Discussionmentioning

confidence: 99%

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Mn-Mo-W Oxide Anodes for Oxygen Evolution in Seawater Electrolysis for Hydrogen Production

2009

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IrO 2 /Ti-supported -MnO 2 -type Mn-Mo-W triple oxide anodes were prepared by anodic deposition in MnSO 4 -Na 2 MoO 4 -Na 2 WO 4 -H 2 SO 4 solutions. The performance of anodes for oxygen evolution reaction during electrolysis of 0.5 kmol m À3 NaCl solution was examined at 1000 Am À2 . The stability, kinetics and physicochemical properties of the oxide deposit anodes were characterized by iR-corrected galvanostatic polarization, gravimetric, X-ray photoelectron spectroscopy and X-ray diffraction techniques. The addition of tungsten to the Mn-Mo oxide enhanced the oxygen evolution efficiency of anodes. electrolyte of pH 0 showed the best performance among anodes prepared in this work. The high performance was attributed to the formation of single phase triple oxide with optimum composition, thickness and defect concentration. Tungsten addition beneficially exerts its effect via increasing the electrical conductivity of oxide deposits. The deposition mechanism of the oxides was discussed in terms of stability and population of Mn 3þ species at the anode/electrolyte interface.

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“…2 They have been used for a wide range of industrial catalytic applications: ozone decomposition, 3 photocatalytic oxidation of organic pollutants and wastewater treatment, 4 nitric oxide reduction, [5][6][7][8] selective oxidations of carbon monoxide, 9 alcohols 10-12 and others. Manganese dioxide is the preferred structure of manganese oxides for electrochemical applications due to its suitably high density and purity, electrochemical activity under a range of discharge conditions, as well as relatively inexpensive commercial production; 13 it is by far the most common electroactive cathode material used in primary batteries.…”

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confidence: 99%

Manganese Dioxide Graphite Composite Electrodes: Application to the Electroanalysis of Hydrogen Peroxide, Ascorbic Acid and Nitrite

et al. 2007

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Hydrothermal MnO2: synthesis, structure, morphology and discharge performance

Cited by 98 publications

References 23 publications

Preparation of nano-structured cryptomelane materials for catalytic oxidation reactions

Preparation of nano-structured cryptomelane materials for catalytic oxidation reactions

Mn-Mo-W Oxide Anodes for Oxygen Evolution in Seawater Electrolysis for Hydrogen Production

Manganese Dioxide Graphite Composite Electrodes: Application to the Electroanalysis of Hydrogen Peroxide, Ascorbic Acid and Nitrite

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