Energy Efficiency Improvement of Alkaline Water Electrolysis by using 3D Ni Cathodes Fabricated via a Double-Template Electrochemical Process

Abstract

Alkaline water electrolysis is one of the easiest methods for hydrogen production, offering the advantage of simplicity. Moreover, it represents an environmentally friendly technology for production of high purity hydrogen. Nevertheless, the elevated production costs due to low conversion efficiency and electrical power expenses can be named as the main drawbacks of electrochemical hydrogen production. This work is focused on the development and characterization of 3D porous Ni cathodes for alkaline electrolyzers. The electrodes were synthesized by nickel electrodeposition on copper foams obtained from hydrogen bubbles dynamic templates (double-template electrochemical process). The developed electrodes were characterized by SEM, confocal laser scanning microscopy, and EDX. The electrocatalytic performance of the developed electrodes for hydrogen evolution reaction (HER) was evaluated in 30 wt.% KOH solution by using hydrogen discharge curves and galvanostatic tests. Results show that the use of the developed electrodes as cathodes in electrolysis systems makes possible an energy saving of ca. 25% in conditions at which industrial alkaline water electrolysis is carried out, in comparison with the smooth commercial Ni electrodes.