Open AccessInexpensive and Efficient Alkaline Water Electrolyzer with Robust Steel-Based Electrodes
Author(s) -
Billal Zayat,
Debanjan Mitra,
S. R. Narayanan
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/aba792
Subject(s) - alkaline water electrolysis , electrolysis , electrode , materials science , hydrogen production , nickel , potassium hydroxide , electrolysis of water , separator (oil production) , hydroxide , inorganic chemistry , electrolytic cell , metallurgy , hydrogen , chemical engineering , chemistry , electrolyte , thermodynamics , physics , organic chemistry , engineering
Electrolysis of aqueous solutions of alkali is a promising approach for the production of pure hydrogen. For this approach to be economical on a large scale, the overpotentials for the electrode reactions and the high-cost of nickel-based electrode substrates must be reduced. We report here on the performance of an “all-iron” electrolyzer cell that uses inexpensive steel-based electrodes. This alkaline water electrolyzer uses a steel mesh coated with a thin catalytic coating of alpha-nickel hydroxide for the oxygen evolution electrode, and another steel mesh sputter-coated with nickel and molybdenum for the hydrogen electrode. An alkaline electrolyzer with these steel-based electrodes, a commercial Zirfon® separator, and a solution of 30% potassium hydroxide exhibited an electrolysis cell voltage of 1.83 V and 1.71 V at 100 mA cm −2 when operating at 23 °C and 70 °C, respectively. We show that the performance of the steel-based electrodes is comparable to commercial electrodes based on nickel substrates. When the cell was operated continuously for 100 h at 1 A cm −2 at 23 °C, there was no measurable loss in performance, providing a preliminary confirmation of the robustness of these iron-based electrodes and electrocatalysts. We conclude that cost-effective iron-based electrolyzers could be a promising route to low-cost hydrogen production.