The effect of halides, pseudohalides, and some organic substances on the initial rate of peroxodisulphate formation

1981 ◽  
Vol 46 (11) ◽  
pp. 2809-2817 ◽  
Author(s):  
Jan Balej ◽  
Martin Kadeřávek
Keyword(s):  
Anodic Polarization ◽  
Initial Rate ◽  
Polarization Curves ◽  
Oxidation Products ◽  
Total Current ◽  
Organic Substances ◽  
Current Yield ◽  
Platinum Anode ◽  
Low Degree ◽  
Total Current Density

The effects of various additions of halides, pseudohalides and selected organic substances on the overall anodic polarization curves and the polarization curves of oxygen evolution and peroxodisulphate formation were examined under conditions of low degree of sulphate-to-peroxodisulphate conversion. Of the tested substances, SCN- and CN- ions, thiourea, urea and acetonitrile have proved to cause the greatest increase in the current yields of peroxodisulphate. However, the current yield varies as a function of the concentration of additive and the total current density, and goes through a maximum in both cases. The observed phenomena are discussed in terms of potential-dependent adsorption of additives or their oxidation products or intermediates on the oxidized surface of platinum anode.

Effect of various cations on the initial rate of formation of peroxodisulphates

1980 ◽  
Vol 45 (8) ◽  
pp. 2272-2282 ◽  
Author(s):  
Jan Balej ◽  
Martin Kadeřávek
Keyword(s):  
Sulphuric Acid ◽  
Oxygen Evolution ◽  
Anodic Polarization ◽  
Initial Rate ◽  
Degree Of Conversion ◽  
Polarization Curves ◽  
Mixed Solutions ◽  
Low Degree ◽  
Partial Polarization

Preparation of peroxodisulphates by electrolysis of mixed solutions of sulphuric acid and various sulphates was studied at low degree of conversion; the partial polarization curves of peroxodisulphate formation and of oxygen evolution obtained from the overall anodic polarization curves and current yields of the principal anodic processes were examined. The mechanism of the effect of various cations on the rate of anodic formation of peroxodisulfates is discussed.

Study of Effect of Ce-Rich Mixed Rare Earth on Corrosivity of New 5XXX Series Aluminium Alloys

2011 ◽  
Vol 314-316 ◽  
pp. 1449-1455 ◽  
Author(s):  
Hua Shen ◽  
He Liang ◽  
Wei Dong Yang ◽  
Bing Xiang Liu ◽  
Tian Shu Li ◽  
...  
Keyword(s):  
Rare Earth ◽  
Aluminium Alloys ◽  
Anodic Polarization ◽  
Corrosion Current ◽  
Polarization Curves ◽  
Nyquist Diagram ◽  
Rare Earth Content

In this paper, AL-Mg-Mn-RE series alloys are becamed object of study.They are prouced with pure alumimum, pure Mg,electrolytic Mn and mix rich Ce rare earth. The effect of rare earth content on the resistance of the Al-Mg-Mn-RE series alloys are investigated by using Anodic polarization curves, electrochemical impendance spectroscopy. The results showed that their corrosivity is influenced by RE content in aluminum alloys.NO.3.3 impedance of Al-Mg-Mn-RE alloys is larger in the Nyquist diagram and its corrosion current of alloy decreases obviously. Then corrosivity of alloy is the best and the RE content is 0.3%,When the RE content is higher or lower than it that corrosivity isn’t improved but descended.

Effect of Rare Earth on the Inclusions and Pitting Resistance of Ferrite Stainless Steel

2012 ◽  
Vol 531 ◽  
pp. 47-50
Author(s):  
Xiao Liu ◽  
Jian She Li
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Rare Earth ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Anodic Polarization ◽  
Electrochemical Methods ◽  
Polarization Curves ◽  
Metallographic Examination ◽  
Pitting Corrosion Resistance

The anodic polarization curves of 430 ferrite stainless steels with various RE contents in 3.5% NaCl neutral solutions have been measured by electrochemical methods. The effect of RE on pitting corrosion resistance of 430 ferrite stainless steels has been studied by the metallographic examination. The results show that sulfide and other irregular inclusions are modified to round or oval-shaped RE2O2S and RES after adding RE to 430 ferrite stainless steesl. RE makes sulfide, and other irregular inclusions change to dispersed round or oval-shaped RE inclusions, effectively inhibits the occurrence of pitting corrosion, thereby enhancing the corrosion resistance of 430 ferrite stainless steels.

Effect of Ce on the Inclusions and Pitting Resistance of 2Cr13 Stainless Steel

2012 ◽  
Vol 602-604 ◽  
pp. 376-379 ◽  
Author(s):  
Xiao Liu ◽  
Long Mei Wang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Anodic Polarization ◽  
Electrochemical Methods ◽  
Polarization Curves ◽  
Metallographic Examination ◽  
Pitting Corrosion Resistance

The anodic polarization curves of 2Cr13 stainless steel with various RE contents in 3.5% NaCl neutral solutions have been measured by electrochemical methods. The effect of Ce on pitting corrosion resistance of 2Cr13 stainless steel has been studied by the metallographic examination. The results show that sulfide and other irregular inclusions are modified to round or oval-shaped Ce2O2S and CeS after adding Ce to 2Cr13 stainless steel.Ce makes sulfide, and other irregular inclusions change to dispersed round or oval-shaped Ce inclusions, effectively inhibits the occurrence of pitting corrosion, thereby enhancing the corrosion resistance of 2Cr13 stainless steel.

Effect of Nitrite Ions on Polarization Behavior of Steel Immersed in Simulated Concrete Pore Environments

2013 ◽  
Vol 368-370 ◽  
pp. 919-924
Author(s):  
Zhong Lu Cao ◽  
Makoto Hibino ◽  
Hiroki Goda
Keyword(s):  
Polarization Curve ◽  
Current Density ◽  
Linear Polarization ◽  
Anodic Polarization ◽  
Cathodic Polarization ◽  
Corrosion Current ◽  
Anodic Polarization Curve ◽  
Polarization Curves ◽  
Passive State ◽  
Nitrite Concentration

The influence of nitrite concentration on the linear polarization curves of steel, Tafel slope and Stern-Geary constant B have been investigated in three different pH environments simulating the highly alkaline environment, carbonated environment and neutral environment that really existed on the surface of steel in concrete. The results indicate that when the steel is in passive state, the presence of nitrite has little influence on anodic/cathodic polarization curves and Stern-Geary constant B; but when the steel is corroded, the presence of nitrite not only reduces the current density of anodic polarization curve but also decreases the value of Stern-Geary constant B. If this influence is not considered in practical corrosion measurement, the corrosion current will be overestimated.

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