Stainless steel as OER electrode in alkaline water electrolysis
Hamid Reza Zamanizadeh, Frode Seland, Svein Sunde
Norwegian University of Science and Technology (NTNU), Department of Materials Science and Engineering
Water splitting to oxygen and hydrogen is made possible through applying an external voltage exceeding the theoretical voltage (reversible voltage). The overvoltage needed depends on the loss terms coming into play in a real electrolysis cell. The activation overpotential is the dominating loss term at low current densities. The activation overpotential, which is at the electrode-electrolyte interface, is an indication of the reaction kinetics and hence the electro-catalytic properties of the electrode. Electrodes made of Ni and Ni alloys are known to be stable and relatively good electrocatalysts for both the oxygen and hydrogen evolution reactions in alkaline media [1, 2]. Even though Ni belongs to the non-noble metals and have beneficial properties in alkaline electrolytes the price and durability of the nickel-based electrodes, which are currently in use by industry, are still needed to be improved. Recent literature claim that proper activated stainless steel can have high catalytic activity and durability compared to other nickel based electrodes and be served as electrode for the oxygen evolution reaction [3, 4]. In the first stage of this research, 316L stainless steel will be activated through electro-oxidation in order to achieve an electrode surface with beneficial properties. Durability and activity of the prepared samples will be analyzed using cyclic voltammetry and potential step measurements at a lab scale in alkaline environment and ambient conditions. The correlation between surface properties and the obtained performances will be considered with SEM, EDS and XPS.
1. Han, L., S. Dong, and E.J.A.M. Wang, Transition‐Metal (Co, Ni, and Fe)‐Based Electrocatalysts for the Water Oxidation Reaction. 2016. 28(42): p. 9266-9291.
2. Harang, H., et al., Method for preparing active cathodes for electrochemical processes. 1979, Google Patents.
3. Moureaux, F., et al., Development of an oxygen-evolution electrode from 316L stainless steel: Application to the oxygen evolution reaction in aqueous lithium–air batteries. 2013. 229: p. 123-132.
4. Schäfer, H. and M.J.A.E.L. Chatenet, Steel: the resurrection of a forgotten water-splitting catalyst. 2018. 3(3): p. 574-591.