Expected Outcome:Low-carbon hydrogen, produced via methods such as proton exchange membrane water electrolysis (PEMWE), offers a promising alternative to fossil fuel consumption in various energy sectors. However, the practical implementation of the clean energy transition requires: (i) sustainable supplies of critical raw materials such as platinum group metals (PGMs) and (ii) strategic processed materials such as fluoropolymers. Increasing material recycling rates can: (i) reduce environmental impact, (ii) enhance production efficiency, and (iii) create new jobs. These outcomes are aligned with the European Commission’s goal to strengthen European value chains. Additionally, the European Commission and industry stakeholders aim to increase electrolyser manufacturing capacities tenfold by 2025 to support the EU’s target of 10 million tons of renewable hydrogen production by 2030 (REPowerEU)[1].

The core and key component of Proton Exchange Membrane Water Electrolysers (PEMWEs) is the catalyst-coated membrane (CCM). To facilitate water splitting into its constituent elements (i.e., hydrogen and oxygen), iridium (Ir)-based catalysts at the anode, platinum-based electroc... ver más

Expected Outcome:Low-carbon hydrogen, produced via methods such as proton exchange membrane water electrolysis (PEMWE), offers a promising alternative to fossil fuel consumption in various energy sectors. However, the practical implementation of the clean energy transition requires: (i) sustainable supplies of critical raw materials such as platinum group metals (PGMs) and (ii) strategic processed materials such as fluoropolymers. Increasing material recycling rates can: (i) reduce environmental impact, (ii) enhance production efficiency, and (iii) create new jobs. These outcomes are aligned with the European Commission’s goal to strengthen European value chains. Additionally, the European Commission and industry stakeholders aim to increase electrolyser manufacturing capacities tenfold by 2025 to support the EU’s target of 10 million tons of renewable hydrogen production by 2030 (REPowerEU)[1].

The core and key component of Proton Exchange Membrane Water Electrolysers (PEMWEs) is the catalyst-coated membrane (CCM). To facilitate water splitting into its constituent elements (i.e., hydrogen and oxygen), iridium (Ir)-based catalysts at the anode, platinum-based electrocatalysts at the cathode, and a proton exchange membrane (PEM) are utilised. Furthermore, state-of-the-art membranes are based on perfluorosulfonic acid (PFSA) polymers.

Currently, no viable alternatives to Ir as an electrocatalyst provide the same efficiency and durability under the high-voltage and acidic conditions prevalent in PEMWE. The implications for Ir demand can be significant if PEMWE anodes with a low loading of Ir and improved collection systems for end-of-life Ir-containing materials from other industries are not developed[2].

Another crucial component of PEMWEs is the proton exchange membrane, which is used as a barrier between anode and cathode and selectively allows the migration of protons. Currently, no technologically mature alternatives to replace PFSA-based membranes in PEM technologies can meet the required industrial targets (e.g., performance, durability, lifetime, and industrial scaling). PFSAs are also used in the formulation of the electrocatalytic layers. Currently, the end-of-life (EoL) path for PFSA materials is incineration in dedicated ovens, which destroys the valuable ionomer in the process and requires scrubbers to handle the highly corrosive fluor acids in the exhaust fumes. Recycling the polymer at EoL is crucial to minimise environmental impacts of per- and polyfluoroalkyl substances, and reduce the CO2 footprint of end of life (EoL) stacks by providing a second life for the ionomer. Therefore, this topic aims to contribute to the industrial solutions for addressing emerging environmental concerns and regulations related to fluorinated materials in the long term.

Project results are expected to contribute to the following outcomes:

Contributing to the EU’s net-zero strategy by providing technological guidelines for recycling Ir and the PFSA ionomer;Demonstrating the ability to alleviate potential Critical Raw Material (CRM) shortages and increased supply chain resilience for PEMWE manufacturing in the EU;Developing standardised test method(s) for evaluating EoL PFSA ionomer and Ir. Project results are expected to contribute to the following objectives and Key Performance Indicators (KPI) of the Clean Hydrogen Joint Undertaking (JU) Strategic Research and Innovation Agenda (SRIA)[3]:

Minimum CRMs/PGMs (other than Pt) recycled from scraps and wastes (30% by 2024, 50% by 2030);Minimum ionomer recycled from scraps and wastes (70% by 2024, 80% by 2030). Project results are expected to contribute to the following objectives:

Analyse the effectiveness and efficiency of Ir recycling technologies with respect to costs and environment;Minimum purity thresholds for recycled ionomer that will be used in electrochemical, hydrogen-related applications: >99,5%. Bivalent Metal Ions (Fenton-metals) impurities < 15 ppm and other impurities < 500 ppm;Performance and durability of a membrane produced from mixed sources to be comparable to a state-of-the-art reference assessed within PEMWE applications;Delivery of viable test methods to assess the degradation state of end-of-life materials;Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) of both (Ir, ionomer) recycling routes. Scope:This topic aims at simultaneously recycling Ir and ionomers after catalyst-coated membrane (CCM) separation from the PEMWE stack at the EoL and/or from scraps and waste. The novelty and contribution of this topic is to understand the impact of the separation process of the waste stream on the ionomer and PGMs (possible impurities, degradation of the polymer’s molecular structure, change in physical/chemical properties, performance, etc.). This fundamental understanding of material degradation is crucial for optimising their quality before their re-use in PEMWE cells to ensure sustainable circularity. Recycling efforts are also being pursued in projects, such as SUSTAINCELL[4] and BEST4Hy[5]. The critical difference is that the BEST4Hy project targets fuel cell technologies and platinum only, while this topic focuses on PEMWE technology, specifically addressing the recycling of Ir and the ionomer. Further, the project funded by this call can contribute to and be complemented by EU-funded projects on sustainable hydrogen production, such as CLEANHYPRO[6] and H2SHIFT[7]. CLEANHYPRO could facilitate (partial) testing within the scope of the open innovation test bed whereas H2SHIFT could complement in the need of a techno-economic analysis.

The scope of the project should include:

Development of new measurement technologies for characterising the degradation state of ionomer in both the PEM and the electrocatalytic layers;Assessment of physical-chemical properties of membranes from recycled ionomer and mesoscale morphology;Development of new methods to separate the ionomer;Manufacturing of CCMs with Ir and recycled ionomer from production waste, and assessment of their beginning-of-life performance and durability via accelerated stress tests (ASTs) in PEM water electrolysis single cell or short stacks (>1000 hrs cell test and comparison to a short stack comprising of a virgin ionomer membrane)[8];Evaluation and demonstration of the feasibility of the developed recycling processes through techno-economic analysis and life cycle assessment;Evaluation of the possibility of mixing different ionomers (e.g., recycled ionomer with virgin ionomer, different chemistries, etc.) for their application in catalyst layers, membranes, and alternative applications;Manufacturing and testing of membranes from a blend of fluoropolymers from different sources in PEMWE cells, focusing on hydrogen gas crossover, performance and tolerance to accelerated ageing;Evaluation of the performance of recycled ionomer in a laboratory scale environment (e.g., 0.5-10 grams of ionomer); in-situ cell testing and ex-situ testing (scanning electron microscopy, thermogravimetric analysis, tensile testing, swelling behaviour in water, equivalent weight (EW), study of the electrical response) compared to virgin ionomer;Evaluation of the quality of production waste and EoL ionomer batches (e.g., 50-500 g) by: Using the recycled ionomer in the catalyst layer and membrane of PEMWE cells;Analysing of ionomer performance both ex-situ and in cells with accelerated stress testing;Developing new measuring methods for determining ionomer degradation state;Enable short stack testing for at least 1000 h comprising of the recycled ionomer. Verifying the purity of the recycled Ir in collaboration with industrial partners. A purity for Ir of ≥99.9% should be achieved;Verifying the quality and performance of recycled iridium from new recycling methodsAssessing alternative applications of the recycled ionomer;Development of pre-processing guidelines for the input materials (granulation, extraction, homogenisation etc.) to reduce the recycling time and enhance efficiency;Providing advice on stack design considerations to improve the recyclability of ionomer by allowing better separation of CCMs from the stack and ionomer from the CCM;Industrial methods for making membranes and CCMs of the EoL ionomer with the ability to run short stack testing. For the success of the project funded by this call, the project consortium should have access to end-of-life PEMWE components (e.g., cells, MEAs, CCMs) to evaluate real industrial waste and ensure the practical applicability of the developed solutions.

Proposals are expected to build further on the findings and targets of previous projects and find synergies with running projects (namely the projects mentioned above), as well as with the recently established Innovative Materials for EU Partnership.

For additional elements applicable to all topics please refer to section 2.2.3.2.

Activities are expected to start at TRL 3 and achieve TRL 5 by the end of the project - see General Annex B

The JU estimates that an EU contribution of maximum EUR 3.50 million would allow these outcomes to be addressed appropriately.

The conditions related to this topic are provided in the chapter 2.2.3.2 of the Clean Hydrogen JU 2025 Annual Work Plan and in the General Annexes to the Horizon Europe Work Programme 2023–2025 which apply mutatis mutandis.

[1] https://commission.europa.eu/strategy-and-policy/priorities-2019-2024/european-green-deal/repowereu-affordable-secure-and-sustainable-energy-europe_en

[2] A study by the German Mineral Resources Agency (DERA) found that by 2040 the global annual Ir demand for PEMWE can reach 10 tons/year and up to a total of 34 tons/year under the shared socioeconomic pathway (SSP) 1 (Sustainability – Taking the green road).

[3] Clean Hydrogen Partnership, Strategic Research and Innovation Agenda 2021-2027, 2022.

[4] SUSTAINCELL's primary goal is to recycle ionomer and precious group metals (PGM) sourced from end-of-life cells, membrane electrode assemblies (MEAs), scraps, and waste. They are also focused on implementing eco-design principles and environmentally-friendly manufacturing methods to develop new materials and architectures. Additional information at https://cordis.europa.eu/project/id/101101479

[5] Best4Hy aimed at achieving a platinum recovery rate of ≥80% via a hydrometallurgical process and an ionomer recovery of ≥80% via an alcohol dissolution process. Additional information at https://cordis.europa.eu/project/id/101007216

[6] The primary objective of the project is to develop and organise a sustainable Open Innovation Test Bed (OITB) for electrolysis materials and components, providing a network of facilities and services through a Single Entry Point (SEP). Additional information at https://cordis.europa.eu/project/id/101091777

[7] H2SHIFT’s primary focus is to create an innovation and excellence center for innovative hydrogen production technologies open to start-ups and small to medium-sized enterprises from Europe and around the world. Additional information at https://cordis.europa.eu/project/id/101137953

[8] EU harmonised accelerated stress testing protocols for low-temperature water electrolyser, https://publications.jrc.ec.europa.eu/repository/handle/JRC133726

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