Developing robust Electrocatalysts for Oxygen Evolution in Alkaline Sea Water Electrolysers (ASWEs)

Ahmed Abidoye, Mary Ogie, Sumit Roy, Venkatesan Venkata Krishnan

Research output: Contribution to conferencePosterpeer-review

Abstract

Alkaline Water Electrolysis (AWE) for Green Hydrogen production is a critical component of the rapid growth taking place in the hydrogen supply chain. AWE electrodes are inexpensive and abundant, while being high performing, and avoid the very difficult supply chain issues concerning precious metals, like Iridium, encountered in PEM Water Electrolysis. Nevertheless, there are areas of improvement, i.e., higher current densities, more stable operations under transient power supply conditions, and higher round trip efficiencies for reversibly operating cells. To achieve the above, a key component that needs improvement is anodic catalytic activity, viz. Oxygen Evolution Reaction (OER) which needs to be brought down to lower overpotentials. This is also vital, for direct operations in sea water, which is the most abundant electrolyte, available in nature.
In this work, synthesis and performance evaluation of Fe-Ni layered double hydroxide (Fe-Ni LDH) anodes for alkaline water electrolysis (AWE) and alkaline seawater electrolysis (ASWE) are reported. The focus is on the investigation of the oxygen evolution reaction (OER) and to observe the formation/ mitigation of the chlorine evolution reaction (ClER) under sea water under a range of pH’s. The Fe-Ni LDHs were prepared by various methods, such as co-precipitation, hydrothermal synthesis, electrochemical deposition, and dip-coating, and characterized by SEM, EDX and XRD – all of which reveal the expected layered structure. Electrochemical testing was also conducted using 3-electrode cell (Pt as WE, Ag/AgCl as RE) over several electrolytes, and different Fe-Ni ratios. Preliminary results, using Cyclic Voltammetry (CV) have established the efficacy of Fe-Ni LDHs towards OER activity and stability of the anodes and the reduced formation of Cl2 via ClER at high pH. Some of the Cyclic Voltammetry data and Tafel Plots for the deposited Fe-Ni LDHs on Ni-meshes/ foams and glassy carbon electrodes, demonstrate lowering of OER overpotentials, and stable operations, as well.
This work is funded by EPSRC Network for Hydrogen Fuelled Transportation (Network-H2) flexible fund award and is a collaborative work between Teesside University and Durham University.
Original languageEnglish
Publication statusPublished - 25 Apr 2024
EventChemEngDayUK24 - Imperial College London, London, United Kingdom
Duration: 25 Apr 202426 Apr 2024
https://www.imperial.ac.uk/chemical-engineering/news/chemengdayuk2024/

Conference

ConferenceChemEngDayUK24
Country/TerritoryUnited Kingdom
CityLondon
Period25/04/2426/04/24
Internet address

Bibliographical note

Poster board number 35

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