Platinum Electrode Potentials in Mildly Alkaline Sugar Solutions, the Electromotively Active Reductant Present and the Catalytic Effect of Iron on its Oxidation.

1934 ◽  
Vol 38 (8) ◽  
pp. 1061-1074 ◽  
Author(s):  
John M. Ort ◽  
Martin H. Roepke
Keyword(s):  
Catalytic Effect ◽  
Platinum Electrode ◽  
Electrode Potentials

scholarly journals Elements in the Interpretation of Platinum Electrode Potentials in Biological Treatment

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1335-1344 ◽  
Author(s):  
A. Heduit ◽  
D. R. Thevenot
Keyword(s):  
Dissolved Oxygen ◽  
Biological Treatment ◽  
Platinum Electrode ◽  
Surface Characteristics ◽  
Electrode Potentials ◽  
Zero Current ◽  
Experimental Values ◽  
Mixed Potentials ◽  
Ionic Forms ◽  
Current Potential

The zero current potential of a platinum electrode in a biological medium (wastewater, activated sludge) is strongly dependent on the surface characteristics of the metal. It is also influenced by pH (probably Pt/PtO system), dissolved oxygen (O2/OH- system), and ionic forms of nitrogen (NO2-/NH4+ and NO3-/NO2-systems). The experimental values of the coefficients relating the stabilized potential of a platinum electrode to the logarithm of the concentration of the elements under consideration (Nernst equations) are significantly different from the thermodynamic coefficients corresponding to each reaction. The platinum is thus not in equilibrium with the dissolved redox reactants and is likely subject to mixed potentials in which the adsorbed components play an important role.

Some thermodynamic and kinetic properties of H2SO4–H3PO4–H2O–Fe(III) system

2021 ◽  
pp. 1-9
Author(s):  
Ya.G. Avdeev ◽  
Keyword(s):  
Diffusion Coefficients ◽  
Arrhenius Equation ◽  
Platinum Electrode ◽  
Molar Fraction ◽  
Redox Couple ◽  
Kinetic Properties ◽  
Cyclic Voltammogram ◽  
Electrode Potentials ◽  
Half Wave ◽  
Sulfate Complexes

The values of the electrode potentials of the redox couple Fe(III) / Fe(II) and the half-wave potentials of the reactions Fe3+ + e– = Fe2+ и Fe2+ — e– = Fe3+ on the cyclic voltammogram of a platinum electrode in acid solutions containing Fe(III) salts have been measured to characterize the oxidizing ability of the H2SO4—H3PO4—H2O—Fe(III) system. The values of these experimentally obtained parameters are close. A decrease in the oxidizing ability of H2SO4 and H3PO4 mixtures containing Fe(III) with an increase in the molar fraction of H3PO4 in them occurs due to the formation of Fe(III) complexes with phosphate anions which are inferior to their hydrate and sulfate complexes in the oxidizing ability. The temperature coefficients of the electrode potential (dE / dt) of the redox couple Fe(III) / Fe(II) in the H2SO4—H2O, H2SO4—H3PO4—H2O and H3PO4–H2O systems were determined experimentally. The diffusion coefficients of Fe(III) in the studied solutions were calculated based on the Randles—Shevchik equation. The temperature dependence of the diffusion coefficients of Fe(III) cations is satisfactorily described by the Arrhenius equation. The parameters of this equation are calculated.

Ruthenium and Arsenic Electrode Potentials in Fused LiCl–KCl Eutectic

1972 ◽  
Vol 50 (23) ◽  
pp. 3911-3912 ◽  
Author(s):  
T. Folkman ◽  
James A. Plambeck
Keyword(s):  
Platinum Electrode ◽  
Ionic Species ◽  
Potential Range ◽  
Dilute Solutions ◽  
Electrode Potentials

Electrode potentials of the Ru(III)/Ru(0) and As(III)/As(0) systems were measured in dilute solutions of the ionic species in fused LiCl–KCl eutectic at 450 °C. Standard molar electrode potentials of these couples of −0.107 ± 0.007 V and −0.460 ± 0.017 V against a standard molar platinum electrode were calculated. The As(V)/As(III) potential was found to be beyond the potential range of the melt.

scholarly journals Relation Between Redox Potential and Oxygen Levels in Activated-Sludge Reactors

1989 ◽  
Vol 21 (8-9) ◽  
pp. 947-956 ◽  
Author(s):  
Alain Heduit ◽  
Daniel R. Thevenot
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Electrode Potential ◽  
Platinum Electrode ◽  
Plug Flow ◽  
Metal Electrode ◽  
Factor B ◽  
Electrode Potentials ◽  
Oxygen Concentrations ◽  
Sludge Concentration

The importance of dissolved oxygen level in determining the platinum electrode potential in activated sludge has been clearly demonstrated by current-potential curves plotted at different oxygen concentrations. Tests have been carried out, in the laboratory and in full scale treatment plants,to define the relationship between the platinum electrode potential at equilibrium (Eh) and the dissolved oxygen [O2] concentration in the activated sludge. These two parameters obey a law of the form Eh = a + b log [O2]. The measured values of coefficents a and b differ widely to those found from the oxygen reduction reaction in water (a = 0.8 V at pH 7 and b = 15 mV per decade). Factors a and b mainly depend on the sludge loading, the aeration conditions and the sludge concentration. Using non–polished stationary platinum ring electrodes, the following values of a. were obtained (at pH between 7 and 7.6) : + 410 mV/NHE for sludge aerated for several hours without feeding, + 265 mV/NHE for over-aerated/low-loaded sludge (Cm = 0.2 kg BOD.kg MLVSS−1. day−1) and + 180 mV/NHE for high-loaded activated sludge in plug-flow system (Cm = 1 kg BOD.kg MLVSS−1.day −1). Factor b would seem to lie between 55 and 65 mV when the sludge is continuously aerated without feeding.At low loads with excess aeration, it lies between 70 and 90 mV. When the medium is slightly septic at low dissolved oxygen concentrations (insufficient daily aeration time, high sludge concentration or aerators shut down for too long periods), factor b increases and can reach 200 mV. In the same way, at high loads, factor b can become 150 mV. These results demonstrate the importance of dissolved oxygen concentration in the mechanisms which determine the metal electrode potentials in activated sludge. They also illustrate the role that other electroactive species play in the process. The type and concentration of these species depend on parameters such as the sludge loading, the overall oxygen supply, the aeration sequence and the sludge concentration.

Electrodeposition of Cu2O Particles by Using Electrolyte Solution Containing Glucopone as Surfactant

2009 ◽  
Vol 1 (2) ◽  
pp. 18-20
Author(s):  
Dahyunir Dahlan
Keyword(s):  
Indium Tin Oxide ◽  
Pulse Current ◽  
Platinum Electrode ◽  
Saturated Calomel Electrode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Continuous Current ◽  
Oxide Particles ◽  
Cupric Sulphate

Copper oxide particles were electrodeposited onto indium tin oxide (ITO) coated glass substrates. Electrodeposition was carried out in the electrolyte containing cupric sulphate, boric acid and glucopone. Both continuous and pulse currents methods were used in the process with platinum electrode, saturated calomel electrode (SCE) and ITO electrode as the counter, reference and working electrode respectively. The deposited particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that, using continuous current deposition, the deposited particles were mixture of Cu2O and CuO particles. By adding glucopone in the electrolyte, particles with spherical shapes were produced. Electrodeposition by using pulse current, uniform cubical shaped Cu2O particles were produced

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