Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 11, pp. 1713−1718.
Pleiades Publishing, Ltd., 2013.
Original English Text © T.G. Nikiforova, A.A. Stepanova, O.A. Datskevich, V.V. Maleev, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86,
No. 11, pp. 1763−1768.
OF ELECTROCHEMICAL INDUSTRY
Porous Nickel Deposits Formed in the Oxidation
of Alcohols in an Alkaline Medium
T. G. Nikiforova, A. A. Stepanova, O. A. Datskevich, and V. V. Maleev
St. Petersburg State University, St. Petersburg, Russia
Received November 13, 2013
Abstract—Highly porous nickel matrices with varied content of nickel were formed on a glassy graphite electrode
by the electrochemical deposition method. The nickel deposits were studied by pulsed chronoamperometry, im-
pedance spectroscopy, and cyclic voltammetry on a rotating disk electrode in a 1 M KOH solution and in alkaline
solutions containing methanol or ethanol. The process in which a hydroxide ﬁ lm is formed on the nickel surface
in an alkaline solution and the inﬂ uence exerted by this process on the catalytic oxidation of alcohols on nickel
in an alkaline medium are discussed.
At present, there is a considerable interest in
application of nickel-based electrodes for electro-
oxidation of small organic molecules. The oxidation
mechanism of some organic compounds on a nickel
anode in alkaline solutions was considered in [1, 2],
and the catalytic activity of nickel in the reactions of
methanol and ethanol oxidation in an alkaline medium,
in [3–5]. The oxidation of methanol was studied on
nickel electrodes modiﬁ ed with nickel complexes, on
nickel oxides [7–9], and also on nickel alloys [10–16].
The catalytic oxidation of ethanol in alkaline solutions
was examined on nickel nanoparticles supported by
substrates made of various materials [17, 18].
As follows from the published evidence, an
important role is played in the electrocatalytic activity
of nickel-containing electrodes by the redox pair
Ni(OH)2/NiOOH. However, the oxidation mechanisms
of alcohols vary between reports by different authors.
Therefore, of interest is a more detailed study of the
process of recharging of nickel oxides on the electrode
surface in alkaline solutions and of its inﬂ uence on the
catalytic oxidation of alcohols.
We prepared working solutions and made
electrochemical measurements by te procedures
previously described in detail in [19, 20]. All the reagents
used in the study were thoroughly puriﬁ ed and solutions
were prepared with twice-distilled water. The cell and
vessels used in the experiments were also washed with
The study was carried out in a hermetically sealed
three-electrode glass cell having separate cathode
and anode spaces, with an inert gas (argon) bubbled
through the solution. An installation with a rotating disk
electrode was used. The working disk electrode had the
form of a glassy-carbon (GC) rod embedded in Teﬂ on,
with a disk surface area of 0.07 cm
, on which a porous
nickel layer was electrochemically deposited. Prior to
deposition of nickel, the glassy-carbon electrodes were
polished to mirror shine with ﬁ ne emery paper and then
thoroughly washed with twice-distilled water. Porous
nickel was deposited onto the glassy-carbon electrode
by the procedure suggested in  from a 0.2 M NiCl
+ 2 M NH
Cl solution with pH 3.6 in the galvanostatic
mode during a certain time. It was found  that, owing
to the joint discharge of ammonium ions as proton
donors, highly porous metallic nickel matrices are
formed under these electrodeposition conditions, with
a large roughness factor and good mechanical strength.
Using the data of , obtained when determining the