scholarly journals CATHODIC HYDROGEN EVOLUTION ON IRON DISILICIDE. II. ACIDIC SOLUTION

2019 ◽  
Vol 62 (2) ◽  
pp. 59-64
Author(s):  
Maria М. Kuzminykh ◽  
Viktoria V. Panteleeva ◽  
Anatoliy B. Shein
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Sulfuric Acid Solution ◽  
Electrode Material ◽  
Cathodic Process ◽  
Transfer Coefficients ◽  
Iron Disilicide ◽  
Anodic Etching

The kinetics of hydrogen evolution reaction on FeSi2-electrode in 0.5 M H2SO4 solution has been studied using methods of polarization and impedance measurements. With the help of diagnostic criteria for the hydrogen evolution reaction mechanisms based on the analysis of the dependence of the parameters of the equivalent electric circuit on overvoltage, it was established that the reaction of hydrogen evolution on iron disilicide in the sulfuric acid solution proceeds along the discharge - electrochemical desorption route, where desorption is the rate-determining stage. Both stages are irreversible, the transfer coefficients α of the stages are equal, simultaneously the hydrogen absorption reaction by the electrode material proceeds in the kinetic mode (in the whole investigated range of potentials). It was found that the adsorption of atomic hydrogen is described by the equation of the Langmuir isotherm. The influence of thin oxide film on the hydrogen evolution kinetics is noted. The influence of various methods of modifying of the surface of FeSi2-electrode on the kinetics and mechanism of the cathodic process has been studied. It was found that the modification of the disilicide surface by hydrogenation at a current density of i = 30 mA/cm2, an anodic etching in 0.5 M H2SO4 at the potential E = 0.4 V relative to the standard hydrogen electrode, an anodic etching in 1.0 M NaOH at the potential E = 0.1 V, chemical etching in 5.0 M NaOH at 70 °C reduce the overvoltage of hydrogen evolution, but the mechanism of the cathodic process does not change as a result of the electrode modification. Reduction of the overvoltage of hydrogen evolution on iron disilicide is due to the action of two factors: the development of the surface and the change in the composition of the surface layer of the electrode. It has been concluded that FeSi2 in the sulfuric acid solution is a promising electrode material that exhibits activity in the electrolytic hydrogen evolution reaction.

scholarly journals CATHODIC HYDROGEN EVOLUTION ON IRON DISILICIDE. I. ALKALINE SOLUTION

2018 ◽  
Vol 62 (1) ◽  
pp. 38-45
Author(s):  
Maria M. Kuzminykh ◽  
Victoria V. Panteleeva ◽  
Anatoliy B. Shein
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Electrode Material ◽  
Electric Circuit ◽  
Alkaline Electrolyte ◽  
Cathodic Process ◽  
Transfer Coefficients ◽  
Hydrogen Electrode ◽  
Iron Disilicide ◽  
Anodic Etching

The kinetics of hydrogen evolution reaction on FeSi2-electrode in 1.0 M NaOH solution has been studied using methods of polarization and impedance measurements. With the help of diagnostic criteria for the hydrogen evolution reaction mechanisms based on the analysis of the dependence of the parameters of the equivalent electric circuit on overvoltage, it was established that the reaction of hydrogen evolution on iron disilicide in the alkaline electrolyte proceeds along the discharge - electrochemical desorption route, where desorption is the rate-determining stage. Both stages are irreversible, the transfer coefficients of the stages are equal (α1 = α2 = α), simultaneously the hydrogen absorption reaction by the electrode material proceeds in the diffusion mode (in the whole investigated range of potentials). It was found that the adsorption of atomic hydrogen is described by the equation of the Langmuir isotherm. The influence of various methods of modifying of the surface of FeSi2-electrode on the kinetics and mechanism of the cathodic process has been studied. It was found that the modification of the disilicide surface by hydrogenation at a current density of i = 30 mA/cm2, an anodic etching in 0.5 M H2SO4 at the potential E = 0.4 V relative to the standard hydrogen electrode, an anodic etching in 1.0 M NaOH at the potential E = 0.1 V, chemical etching in 5.0 M NaOH at 70 °C reduce the overvoltage of hydrogen evolution, but the mechanism of the cathodic process does not change as a result of the modification. Reduction of the overvoltage of hydrogen evolution on iron disilicide is due to the action of two factors: the development of the surface and the change in the composition of the surface layer of the electrode. It has been concluded that FeSi2 in the alkaline electrolyte is a promising electrode material that exhibits activity in the electrolytic hydrogen evolution reaction.

Effect of bismuth on hydrogen evolution reaction on lead in sulfuric acid solution

2005 ◽  
Vol 144 (2) ◽  
pp. 338-345 ◽  
Author(s):  
Y.M. Wu ◽  
W.S. Li ◽  
X.M. Long ◽  
F.H. Wu ◽  
H.Y Chen ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Sulfuric Acid Solution

scholarly journals СОСТАВ, СТРУКТУРА И ЭЛЕКТРОХИМИЧЕСКАЯ АКТИВНОСТЬ СИЛИЦИДА ТИТАНА В РЕАКЦИИ ВЫДЕЛЕНИЯ ВОДОРОДА

2021 ◽  
Vol 11 (4) ◽  
pp. 263-270
Author(s):  
V.V. Tretyakova ◽  
◽  
A.E. Ponomareva ◽  
V.V. Panteleeva ◽  
А.B. Shein ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Hydrogen Evolution ◽  
Sulfuric Acid Solution ◽  
Differential Capacitance ◽  
Titanium Silicide ◽  
Silicon Dioxide Film ◽  
X Ray ◽  
Composition And Structure ◽  
Face Centered

The phase composition and structure of titanium silicide have been investigated by X-ray diffraction and X-ray spectral microanalysis methods. It has been found that the investigated silicide is a singlephase system consisting of a high-temperature TiSi2 modification with a rhombic face-centered lattice. The cathodic behavior of the TiSi2 electrode has been studied by the methods of polarization and capacitance measurements. It has been found that the cathodic potentiostatic curves of silicide in solutions of 0,5 M H2SO4; 0,5 M H2SO4 + 0,005 M NaF and1,0 M NaOHhave Tafel sections with slopes of 0,120; 0,097 and 0,109 V and they are characterized by the values of the hydrogen evolution overvoltage 0,90; 0,64 and 0,74 V (at i = 1 A/cm2), respectively. Titanium disilicide in sulfuric acid solution belongs to materials with a high overvoltage of hydrogen evolution, but in a fluoride-containing sulfuric acid solution and in an alkaline solution - to materials with a low overvoltage of hydrogen evolution. Based on measurements of the differential capacitance of the TiSi2 electrode (at f = 10 kHz), it has been concluded that a thin silicon dioxide film (Si + 2H2O → SiO2 + 4H+ + 4e–)is present on the surface of the silicide in the acidic fluoride-free electrolyte.

A Kinetic-Mechanistic Study of The Hydrogen Evolution Reaction in Sulfuric Acid Solutions with Different Electrode Materials

2012 ◽  
Vol 15 (3) ◽  
pp. 225-231 ◽  
Author(s):  
J.C. Fuentes-Aceituno ◽  
G.T. Lapidus
Keyword(s):  
Sulfuric Acid ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Electrode Materials ◽  
Electrical Potential ◽  
Mechanistic Study ◽  
Recombination Reaction ◽  
Acid Solutions ◽  
Transfer Coefficients ◽  
Sulfuric Acid Solutions

The hydrogen evolution reaction (HER) has been studied extensively due to the potential application of molecular hydrogen H2as a green fuel. Recently this particular reaction attracted the attention of several electrometallurgical researchers because of another promising application, in which the monoatomic hydrogen species H· (intermediate product of HER) is employed as a reducing agent for copper-sulfide minerals. Consequently, knowledge about the kinetics, mechanisms and rate determining step (rds) of HER in sulfuric acid solutions employing aluminum, copper, Inconel® or glassy carbon(GC) cathodes is necessary to determine the under and overpotential domains where H2 and H· can be generated in a selective manner. Analyses of Tafel plots and the charge transfer coefficients, revealed two electrical potential zones for copper, Inconel and GC, where the monoatomic hydrogen can be recombined chemically or electrochemically to H2 as the rds. On the other hand, with aluminum, only the electrochemical recombination to H2 occurs as the rds. A catalytic effect on the hydrogen recombination reaction was also found when ferrous ion is contained in the solution. Finally, it was determined that aluminum is the most efficient electrocatalyst for producing H· and H2, followed by inconel, copper and GC.

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