Impedance studies of porous lanthanum-phosphate-bonded nickel electrodes in concentrated sodium hydroxide solution

Electrodeposited, Ni-based, non-noble metal coatings as cathodes for hydrogen evolution in chlor-alkali electrolysis

“…The EIS response for porous electrodes has been theoretically treated [33,34] and experimentally investigated [35,36] by Lasia et al [33][34][35][36], using the first model defined by R. de Levi in 1967 [32]. Characteristic of all, theoretical treatments [33,34] and experimental investigations [35,36] is a linear dependence of Z " vs. Z ', with the slope of about 1 at the highest frequencies. Hence, the ohmic resistance (used for IR drop correction) was obtained by the extrapolation of Z " vs. Z ' linear dependence to the Z ' axes (as marked in the inset of Fig.…”

“…12), Nyquist plots are characterized by linear dependence of Z " vs. Z ', with the slope of about 1, indicating the presence of pores [32][33][34][35][36]. The EIS response for porous electrodes has been theoretically treated [33,34] and experimentally investigated [35,36] by Lasia et al [33][34][35][36], using the first model defined by R. de Levi in 1967 [32]. Characteristic of all, theoretical treatments [33,34] and experimental investigations [35,36] is a linear dependence of Z " vs. Z ', with the slope of about 1 at the highest frequencies.…”

Hydrogen evolution reaction at nickel boride electrodes in aqueous and in aqueous methanolic and ethanolic solutions

“…The CPE model was therefore proposed for cases where a depressed semicircle is observed on complex plane plots. In this case, the double layer capacity is substituted by the CPE and its impedance equals (15): where w is the angular frequency of the ac signal, T is a constant, + is the phase angle related to the surface roughness, and parameter A is equal to 1/R,, where R,, is the charge transfer resistance (7,(16)(17)(18)(19)(20)(21)(22)(23). For an ideally flat electrode, + is equal to 1 and, thus, T is equal to C,,.…”

A comparison of nickel boride and Raney nickel electrode activity in the electrocatalytic Hydrogenation of Phenanthrene

“…The ECH of phenanthrene on NiIRaNi electrodes confirms that Po,, does reflect the activity of the catalytic material, since the Po,, value varies between that of a 100% fractal Ni electrode and that of a 100% RaNi electrode as the NiRaNi ratio decreases. phenanthrene, we determined their intrinsic activity and their real surface for the HER in 1 M NaOH at 25°C using Tafel plots and ac impedance measurements (4,(7)(8)(9)(10)(11)(12). Such studies could not be carried out on the pressed RaNi electrodes because of the continuous leaching of the Raney alloy particles inside the disc during the experiments, causing the particles to fall apart.…”

“…For the determination of the double layer capacity (Cdl) by ac impedance, the CPE model was used (eqs. [7] and [8] (13) where o is the angular frequency of the ac signal, T is a constant, + is the phase angle related to the surface roughness, R, is the solution resistance, and parameter A is equal to l/Rct where R,, is the charge transfer resistance (4,(7)(8)(9)(10)(11)(12)14)). For an ideally flat electrode, + is equal to 1 and thus T is equal to Cdl.…”