In the context of renewable energy, electrochemical energy converters are gaining increasing importance, with fuel cells and electrolysers being key technologies. Among these proton exchange membrane (PEM) fuel cells represent a major advancement and have been adopted in the first commercial fuel cell vehicles. However, the acidic environment in PEM fuel cells (PEMFCs) and proton exchange membrane electrolysers (PEMELs) necessitates the use of expensive and scarce noble metals, limiting their scalability. The emergence of alkaline anion exchange membranes (AEMs) offers a promising alternative, enabling the use of more abundant and cost-effective materials. This innovation combines the benefits of both alkaline and acidic systems, with the potential to reduce overall system costs while maintaining high performance. This research aims to identify the most efficient and economically viable method for hydrogen production, with a focus on alkaline technologies. To ensure the competitiveness of AEM-based systems a comprehensive evaluation of their durability, safety and efficiency was conducted. Electrochemical in-situ techniques and physical ex-situ diagnostics were applied to assess various membranes, electrodes and cell configurations. As a result, significant progress was made in the optimisation of AEM electrolysers. A novel high-pressure alkaline electrolyser was developed, capable of operating at an unique differential pressure of up to 100 bar—an unprecedented achievement in the field, far exceeding the current commercial limit of 30 bar. Remarkably, this performance was reached using completely noble-metal-free electrodes, while achieving a power output comparable to that of significantly more expensive PEM electrolysis systems. Furthermore, the developed configuration demonstrated a power density that surpasses conventional alkaline electrolysers by several hundred percent, marking a major step forward in high-efficiency, low-cost hydrogen production.
| Date of Award | 3 Oct 2025 |
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| Original language | English |
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| Supervisor | Rakesh Mishra (Main Supervisor) & Enno Wagner (Co-Supervisor) |
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