Nanocomposites and nanomaterials

Electrooxidation of ethanol 
on nickel-copper multilayer metal hydroxide electrode
Maizelis A.A.
Department of Technical Electrochemistry, National Technical University «Kharkiv Polytechnic Institute», Kyrpychova str., 2, Kharkiv-61002, Ukraine. 
E-mail: a.maizelis@gmail.com

The study of the electrochemical oxidation of ethanol has attracted great interest because of their important application in direct alcohol fuel cells. Nickel-containing electrode materials are promising for the replacement of platinum in alkaline media. However, it is necessary to improve their characteristics in order to ensure the advisability of replacing platinum.  It is shown [2] that the methanol electrooxidation on the Ni-Cu alloy (40% Cu) modified electrode was significantly active than on pure Ni.
The comparing of behavior of electrodes in reaction of ethanol oxidation in an alkaline electrolyte is presented. The tested electrodes were with nickel-copper alloy coating and a new multilayer coating consisting of alternating layers of nickel-copper alloy with thickness of about 100 nm and a mixture of metals with their hydroxides. It is shown that both alloy and multilayer coating (the catalytic activity of which was determined earlier [3] in methanol oxidation reaction) show the catalytic activity in ethanol oxidation reaction. Ethanol oxidation on the studied electrodes proceeds irreversibly. The parameters of this reaction are determined in both cases using cyclic voltammetry and chronoamperometry methods. The influence of ethanol concentration, composition of the layers of multilayer coating and time of their formation, as well as the α-Ni(OH)2 to β-Ni(OH)2 polymorphic forms ratio in the layers on the rate of ethanol oxidation are considered.
The multilayer coating provides greater number of active sites for the reaction as compared to surface of the alloy (deposited under the same conditions as the alloy layers in the multilayer coating) and is more effective in the ethanol oxidation reaction.

1.	Danaee I., Jafarian M., Forouzandeh F., Gobal F., Mahjani M.G. Electrochemical impedance studies of methanol oxidation on GC/Ni and GC/NiCu electrode // Int J Hydrogen Energy.-2009.-34(2).-P. 859-869.
2.	Maizelis A., Bairachniy, B. Electrochemical formation of multilayer metal and metal oxide coatings in complex electrolytes. In international conference on nanotechnology and nanomaterials. P. 557-572. Springer, Cham.