Abstract
Improvement of alkaline water electrolysis is a key enabler for quickly scaling up green hydrogen production. Fe is omnipresent within most industrial alkaline water electrolyzers and its effect on electrolyzer performance needs to be assessed. We conducted three-electrode and flow cell experiments with electrolyte Fe and Ni electrodes. Three-electrode cell experiments show that Fe ([Fe] = 6–357 μM; ICP-OES) promotes HER and OER by lowering both overpotentials by at least 100 mV at high current densities (T = 35°C–91°C). The overpotential of a zero-gap flow cell was decreased by 200 mV when increasing the Fe concentration ([Fe] = 13–549 μM, T = 21°C–75°C). HER benefits from the formation of Fe dendrite layers (SEM/EDX, XPS), which prevent NiHx formation and increase the overall active area. The OER benefits from the formation of mixed Ni/Fe oxyhydroxides leading to better catalytic activity and Tafel slope reduction.
| Original language | English |
|---|---|
| Article number | 108695 |
| Number of pages | 17 |
| Journal | iScience |
| Volume | 27 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 19 Jan 2024 |
Funding
We gratefully acknowledge the funding by the NWO (KICH1.ED04.20.001). Further, we would like to acknowledge the experimental work performed by the TU/e DBL students and the help from the technicians of the Sustainable Process Engineering group.
| Funders | Funder number |
|---|---|
| Nederlandse Organisatie voor Wetenschappelijk Onderzoek | KICH1.ED04.20.001 |
Keywords
- Fe
- iron
- Electrolysers
- electrolysis
- Alkaline
- hydrogen
- oxygen
- performance
- Electrolytes
- Electrochemistry
- Applied sciences
