Cluster of projects

Cluster - linked projects

The following projects are linked to each other through the cluster.

The REDHy project will cluster their activities with the other projects granted in the same call. The aim of the clustering is to align the communication and dissemination activities among the projects.


Title: Stable and Efficient Alkaline Water Electrolyzers With Zero Critical Raw Materials for Pure Hydrogen Production

Project description:

Innovative water electrolysis for pure hydrogen production

The EU has set a target of installing at least 40 GW of renewable H2 electrolysers by 2030 as part of its Hydrogen Strategy. However, achieving this goal poses significant challenges for water-electrolysis technology. The current zero-gap alkaline water electrolysis (AWE) has the potential to be cost-effective and scalable, but it requires further optimisation in activity, stability, and gas crossover to increase efficiency and system lifetime. The EU-funded SEAL-HYDROGEN project aims to create a new AWE system that combines classic benefits with advanced innovations. The project proposes using sustainable, cost-effective, two-dimensional, layered double hydroxides (LDH) instead of noble metal-based catalysts. Its objective is to accelerate the commercial uptake of water electrolysis.


Today’s alkaline electrolysers favour current densities over efficiency: to achieve commercially relevant current densities, these systems typically operate at voltages exceeding 2 V/cell, corresponding to electrolyser power consumption of >54 kWh/kg. There are four reasons for employing high voltages: 1) electrodes’ insufficient electrochemical activity, 2) the relatively high gas permeability of commonly employed diaphragms means that improved hydrogen purity can be achieved at high current operation points, 3) the stack designs are not optimised for low-current operation due to very simple flow fields, and 4) high currents are required to achieve attractive electrolyser CAPEX costs (EUR/kW).
Yet, there is a growing consensus that the wider adoption of green H2 is not hindered by electrolyser CAPEX: the costs of green H2 are in most cases vastly dominated by OPEX, which in turn is a direct function of electrolyser efficiency. Thus, to achieve lowest possible levelised cost of H2, efficiency should be prioritised over current density.

EXSOTHyC will optimise electrolyser operation towards lower voltages and higher efficiencies. The innovation is three-fold and addressing all four above-mentioned reasons:
• Alternative pathways to the O2 and H2 evolution reactions by new anode and cathode approaches
• Novel concepts of membrane electrode assemblies with integrated components
• Novel cell design to enhance overall cell efficiency by integrating disruptive concepts

In the project, we adopt an approach combining computer simulations, rapid prototyping, and thorough experimental validation on single cell, SRU and short stack level. In a nutshell, we will combine electrodes made using powder metallurgy with ceramic nanoparticles fabricated by exsolution, leveraging on the synergy that both methods require reducing atmospheres. Also, membrane-electrode assemblies based on Zirfon will be developed. The cell/stack will be backed by computer modelling.


Title: eXperimental Supercritical ElEctrolyser Development

X-SEED aims at developing an innovative alkaline membrane-less electrolyzer that works at supercritical water conditions (>374°C; >220 bar) generating high-quality H2 at pressures over 200 bar. This technology maximizes energetic efficiency, improves circularity, and enhances lifetime, resulting in a more competitive green H2 production. X-SEED validates results at laboratory scale (TRL4) for a single cell and a 5-cell stack. Novel catalysts and electrodes are designed, synthesized, and characterized to ensure high efficiencies. Multiscale modeling and cell design ensure laminar fluid flows, allowing H2 and O2 separation without a membrane. Supercritical conditions and membrane-less configuration reduce the electrochemical work required to generate H2 (as interface resistances across cell components are decreased) and increase system lifetime. This results in an improved voltage and energy efficiency (42 kWh/kg H2), current density (> 3 A/cm2), H2 production rate and robustness (degradation rate < 1%/1000h). X-SEED also integrates circularity and sustainability assessments in decision-making, limiting the use of critical raw materials (below 0.3 mg/W) and using wastewaters both for catalyst production and as a possible electrolyte for the supercritical electrolyser. X-SEED consortium possess extensive technical knowledge and experience in key enabling technologies and areas. These will be utilized to realize multiphysics models of cell and stack (DTU, SNAM, IDN, PMat), manufacture and select the best catalyst and electrodes (LEITAT, PMAT, IDN), and design the cell, the stack, and the test bench to validate the supercritical electrolyzer at a laboratory scale (IDN, PMat, SNAM). In conclusion, X-SEED project’s relevance and added value extend beyond the technological dimension: it will accelerate the H2 ecosystem, supporting Europe in meeting climate targets and maintaining its leadership position as a technological developer, producer, and exporter of green energy.


Title: Anionic Exchange Membrane water ELectrolysis for highLY efficIenTcy sustAinable, and clean Hydrogen production

AEMELIA accepts the challenge to design and prototype AEMEL that meets and surpasses Hydrogen Europe’s 2030 targets for performance, durability, safety and cost. AEMELIA proposes a clear path to reach high current-density (1.5 A cm-2) and low voltage (1.75 V). Energy-efficiency surpasses the 2030 target (46.9 kWh/kg, or 85% of maximum theoretical efficiency), to make 3 times more H2 with less energy compared to XY. LCOH also outshines 2030 targets at 2.5€/kgH2 (17% lower than 2030 target). The degradation rate meets the 2030 target, enabling a 10-year lifetime. These and other KPIs will be validated via the TRL4 prototype of a 5-cell stack at 100 cm² that will deliver 7.2 Nm3/day of H2 at a purity of 99.9% at 15 bar.
The team will develop and test disruptive materials, such as fluorine-free ionomers ; thin, highly-conducting membranes ; PGM-free recombination catalysts ; and ionomer-free electrodes. These components are based on earth-abundant, safe materials. They would be fully scalable via existing manufacturing processes. They will be combined in innovate cell designs, taking into account novel flow-field design based on CFD models. Innovative operating conditions such as high operating temperature and pulsed current will increase energy-efficiency while reducing balance of plant (BoP) and will be tested in single cells, as will the use of impure water for improved LCA and cost. Lastly, disruptive methods for AI-based ionomer development and the measurement of the catalytically-active surface area of non-PGM catalysts will be developed.
Performance, durability, LCA and cost KPIs will be shared with companies to convince them to invest in upscaling after the project. Partners have many success stories in developing disruptive electrochemical materials and systems and bringing them to market. AEMELIA’s market penetration in 2031 is expected to generate 527 M€ in revenues by 2036, and 1172 kt CO2/year avoided compared to steam methane reforming.


Title: Redox-mediated economic, critical raw material free, low capex and highly efficient green hydrogen production technology.

Objective: The REDHy project tackles the limitations of contemporary electrolyser technologies by fundamentally reimagining water electrolysis, allowing it to surpass the drawbacks of state-of-the-art (SoA) electrolysers and become a pivotal technology in the hydrogen economy. The REDHy approach is highly adaptable, enduring, environmentally friendly, intrinsically secure, and cost-efficient, enabling the production of economically viable green hydrogen at considerably increased current densities compared to SoA electrolysers. The REDHy method is based on the findings of numerous EU-funded initiatives and patented by the DLR (TRL2). It is uniting academic and industrial entities across a broad spectrum of expertise. Unlike SoA electrolysers, REDHy is entirely free of critical raw materials and doesn’t require fluorinated membranes or ionomers, while maintaining the potential to fulfil a substantial portion of the 2024 KPIs. In accordance with Europe’s circular-economy action plan, a 5-cell stack with an active surface area exceeding 100 cm2 and a nominal power of 1.5 kW will be developed, capable of managing a vast dynamic range of operational capacities with economically viable and stable stack components. These endeavours will guarantee lasting and efficient performance at elevated current densities (1.5 A cm-2 at Ecell 1.8 V/cell) at low temperatures (60 °C) and suitable hydrogen output pressures (15 bar). The project’s ultimate objective is to create a prototype, validate it in a laboratory setting for 1200 hours at a maximum degradation of 0.1%/1000 hours and achieve TRL4. This final phase will emphasize the potential of the REDHy approach and its crucial role in the upcoming hydrogen economy, secure subsequent investments, and showcase the necessity for ground-breaking, innovative thinking to reach climate objectives in a timely fashion.

Project progress

© 2023 REDHy

The project is co-funded by the European Union and supported by the Clean Hydrogen Partnership and its members. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the Clean Hydrogen Partnership. Neither the European Union nor the granting authority can be held responsible for them.

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