Periodic Reporting for period 1 - SEAL-HYDROGEN (Stable and Efficient Alkaline Water Electrolyzers With Zero Critical Raw Materials for Pure Hydrogen Production)
Reporting period: 2024-01-01 to 2025-06-30
The EU Hydrogen Strategy sets the goal of installing at least 40 GW of renewable H2 electrolysers by 2030, which imposes significant challenges for water-electrolysis technology. Although current zero-gap alkaline water electrolysis (AWE) has potential for cost-effectiveness and scalability, it needs further optimization in activity, stability, and gas crossover to increase efficiency and system lifetime. This project will develop a new class of AWE combining proven benefits of classic systems with cutting-edge innovations in materials science, catalyst design, and process engineering. Driven by an industrial-feasibility vision, a system that is both technically advanced and economically viable for large-scale commercial deployment is pursued. The proposed innovations include highly efficient and earth-abundant two-dimensional layered double hydroxides (LDH) obtained through a straightforward synthetic route and novel processing approaches, offering a sustainable and cost-effective alternative to noble metal-based catalysts. An innovative technology for upscaling the production of LDH layers by direct growth of catalysts in porous transport electrodes will be implemented and explored on commercial separators. The interplay between the substrate, catalyst, and separator will be thoroughly optimized through the development of triple-phase boundary electrodes (catalyst-support-ionomer) structures with improved thermo-mechanical stability. A reliable method based on Raman spectroscopy, will be developed for the precise determination of electrode stability, offering an appropriate quality control of great interest both in research and industry. The optimal design will be assembled and tested, first in single cells of 5 cm², then in 25 cm², and finally scaled to at least 6-cell stack of 300 cm², to demonstrate a next generation technology with improved performance, stability and durability, aimed to accelerate the commercial uptake of water electrolysis and turn green H2 into an economically viable solution.
•Kick off Meeting held in Valencia, Spain, 1-2nd February 2024. Organized by UVEG, with attendance and project commitment from all partners.
•UVEG: synthesis of various binary and ternary LDHs with different transition metals achieved. Chemical, morphological and electrochemical characterization done; first set of materials selected.
•MATTECO: kg-scale production of LDHs completed. Growth of a large surface area electrode for testing by SE and HIERN conducted.
•HORIBA: close collaboration with UVEG and HIERN to define specifications for a new Raman cell to be developed. Cell prototype under validation, and potential commercialization under evaluation.
•HIERN: study of the dissolution of NiFe LDHs by ICP-MS being validated in new cell setup. Optimization of divergent flow cells configuration. Ionomer addition to the catalyst as booster for performance and enhancer of the stability of catalysts under study. Assessment of independent cell components contribution in the cell performance.
•SIEMENS ENERGY: construction of the stack and the test station initiated. Design finalized, holding specifications on Ni substrate properties for the constructed stack.
•2nd Meeting held in Erlangen, Germany, 22nd October 2024. Organized by HIERN, with attendance and project commitment from all partners.
•UVEG: project management (both technical and administrative), including submission of Deliverables and completion of tasks to be done for each partner.
•Workshop with sister projects held in Milan, Italy, 29th January 2025. Organized by Leitat, with attendance of other projects from the HORIZON-JTI-CLEANH2-2023-01-01 call.
•3rd Consortium Meeting held in Lille, France, 12-13 May 2025. Organized by HORIBA, with attendance and project commitment from all partners.
•UVEG: synthesis of various binary and ternary LDHs with different transition metals achieved. Chemical, morphological and electrochemical characterization done; first set of materials selected.
•MATTECO: kg-scale production of LDHs completed. Growth of a large surface area electrode for testing by SE and HIERN conducted.
•HORIBA: close collaboration with UVEG and HIERN to define specifications for a new Raman cell to be developed. Cell prototype under validation, and potential commercialization under evaluation.
•HIERN: study of the dissolution of NiFe LDHs by ICP-MS being validated in new cell setup. Optimization of divergent flow cells configuration. Ionomer addition to the catalyst as booster for performance and enhancer of the stability of catalysts under study. Assessment of independent cell components contribution in the cell performance.
•SIEMENS ENERGY: construction of the stack and the test station initiated. Design finalized, holding specifications on Ni substrate properties for the constructed stack.
•2nd Meeting held in Erlangen, Germany, 22nd October 2024. Organized by HIERN, with attendance and project commitment from all partners.
•UVEG: project management (both technical and administrative), including submission of Deliverables and completion of tasks to be done for each partner.
•Workshop with sister projects held in Milan, Italy, 29th January 2025. Organized by Leitat, with attendance of other projects from the HORIZON-JTI-CLEANH2-2023-01-01 call.
•3rd Consortium Meeting held in Lille, France, 12-13 May 2025. Organized by HORIBA, with attendance and project commitment from all partners.
Thanks to the novel synthetic pathway, highly activated, defective, and clustered LDHs are obtained in a single-step fabrication. Among the 75 different LDH compositions (PGM-free) synthesized and characterised, 5 appeared as the most promising catalyst for the OER. An overpotential reduction range of 120-200 mV compared to bare nickel substrates was measured for these 75 compositions. The parent NiFe LDH with optimised ratio is complemented by the incorporation of other transition metals as alternative catalysts with lowest overpotential values of the electrochemical performance. The evaluation of the stability is focussed on the metal dissolution under operating conditions. With these powder catalysts, inks containing solvents and ionomers are coated with conventional processing techniques such as spray-coating, obtaining porous transport electrodes (PTEs).MATTECO has achieved a significant milestone by developing an innovative technology for up-scaling the production of catalyst layers, avoiding ink processing, which involves the direct growth of catalysts in PTEs, with no limitations in size or morphology.
Furthermore, the project tackles the optimization of the catalyst, support, ionomer, and separator interplay. Modifications of the cell design, like implementing bipolar membranes or the cell operation, such as changing the KOH/NaOH electrolyte concentration in the anode or working in dry cathode/anode conditions, will have strong impacts on the mass transport of the reactants and products directly influencing the cell performance. Moreover, by adapting a reported membrane-less electrolyser with a reference electrode, the catalysts and catalyst layer screening will be performed, splitting the kinetic and mass transport contributions to the total cell voltage of AWE from the cathode and anode separately. With respect to the in-situ characterization espectroelectrochemical Raman under industrially relevant current densities has been carried out for the first time, using the previously optimized catalysts. A new prototype of Raman cell is now under validation and potential commercialization evaluation by HORIBA.
The ultimate objective of this project is to achieve superior performance in 300 cm² 6-cell stack AWE electrolysers ‒to reach similar performance to state-of-the-art AEMWE‒ but still using cost-effective and stable diaphragms and separators. The assemblies will be first tested on single cells of 5 cm², then scaled to 25 cm², and finally to a 6-cell stack of 300 cm². Overall, the team's work offers a promising direction for developing cost-effective and sustainable catalysts and electrodes for water electrolysis, potentially increasing the adoption of technologies based on water electrolysis. It is important to stress that AEMWE fed with 1 M KOH is used as a reference for the consortia, and most of the developments achieved using this technology will be directly extrapolated to AWE. To overcome the significant limitation related to membrane instability, we will perform 300 cm² 6-cell stack testing only on optimized interfaces and using stable diaphragms or separators to ensure reliable results.
In overall, SEAL-HYDROGEN aims to overcome the main barriers that water electrolysis faces through the lab-scale development and validation of single cells in short stacks of 6 cells.
Furthermore, the project tackles the optimization of the catalyst, support, ionomer, and separator interplay. Modifications of the cell design, like implementing bipolar membranes or the cell operation, such as changing the KOH/NaOH electrolyte concentration in the anode or working in dry cathode/anode conditions, will have strong impacts on the mass transport of the reactants and products directly influencing the cell performance. Moreover, by adapting a reported membrane-less electrolyser with a reference electrode, the catalysts and catalyst layer screening will be performed, splitting the kinetic and mass transport contributions to the total cell voltage of AWE from the cathode and anode separately. With respect to the in-situ characterization espectroelectrochemical Raman under industrially relevant current densities has been carried out for the first time, using the previously optimized catalysts. A new prototype of Raman cell is now under validation and potential commercialization evaluation by HORIBA.
The ultimate objective of this project is to achieve superior performance in 300 cm² 6-cell stack AWE electrolysers ‒to reach similar performance to state-of-the-art AEMWE‒ but still using cost-effective and stable diaphragms and separators. The assemblies will be first tested on single cells of 5 cm², then scaled to 25 cm², and finally to a 6-cell stack of 300 cm². Overall, the team's work offers a promising direction for developing cost-effective and sustainable catalysts and electrodes for water electrolysis, potentially increasing the adoption of technologies based on water electrolysis. It is important to stress that AEMWE fed with 1 M KOH is used as a reference for the consortia, and most of the developments achieved using this technology will be directly extrapolated to AWE. To overcome the significant limitation related to membrane instability, we will perform 300 cm² 6-cell stack testing only on optimized interfaces and using stable diaphragms or separators to ensure reliable results.
In overall, SEAL-HYDROGEN aims to overcome the main barriers that water electrolysis faces through the lab-scale development and validation of single cells in short stacks of 6 cells.