There is increasing interest in harnessing sunlight to drive the synthesis of molecular fuels and chemicals, including in particular water photolysis to yield molecular oxygen and hydrogen. This can be achieved either through the coupling of photovoltaic cells and electrolysis, or through direct sunlight conversion by photoelectrodes or photocatalysts, the latter being the focus of this talk. In solar conversion, there is often a critical kinetic mismatch between the lifetimes of initially generated photoexcited states and the timescales of charge extraction / catalysis.  I will start my talk by introducing solar driven fuel synthesis, its motivation and examples of state of the art materials and devices. I will then go on to discuss the charge carrier lifetime challenge in photoelectrochemical and photocatalytic systems. I will contrast this with the smaller lifetime challenges for photovoltaic solar energy conversion. I will then go on to discuss some of our recent studies employing transient optical spectroscopies measuring charge carrier dynamics in photoelectrodes and photocatalysts and how these impact upon the efficiency of solar driven water splitting, covering a range of inorganic, hybrid and organic materials. I will highlight the multi-timescale nature of the challenge – from the ultrafast recombination of excitons and polarons to the seconds time scale of water oxidation catalysis.  I will in particular highlight how recent advances in materials design are enabling the solar driven generation of charges with lifetimes of milliseconds to seconds, long enough to drive interfacial charge transfer and catalysis, drawing upon examples of studies in group on metal oxides, metal-organic-frameworks, organic semiconductors, carbon nitride and gallium nitride. The mechanistic origins of the remarkably long carrier lifetimes vary between materials. However, across these materials classes, long charge carrier lifetimes are enabling substantive advances in the performance of photocatalytic devices. In each case, I will discuss the opportunities, challenges and potential for low cost solar driven hydrogen generation.

The sustainable production of hydrogen via water electrolysis is pivotal to the global transition toward carbon-neutral energy systems. Yet, the dependence on high-purity water remains a critical bottleneck, especially in regions facing freshwater scarcity. Low-grade water sources such as seawater, wastewater, and industrial effluents, offer a vastly abundant alternative, but their complex compositions present major electrochemical and materials challenges, particularly at the oxygen evolution reaction (OER) anode.

In this presentation, I will give an overview of our recent advances in engineering highly selective and robust oxygen anodes tailored for low-grade water electrolysis. Our work centers on the rational design of transition metal catalysts modified through dopant incorporation, surface reconstruction, and nanoscale interface engineering. These strategies enhance not only intrinsic OER activity but also suppress competitive parasitic reactions such as chlorine evolution, which is prevalent in chloride-rich environments. Using a combination of structural and electrochemical analysis, we elucidate the fundamental structure–property relationships that dictate selectivity and long-term stability. We also present performance benchmarks in both synthetic and real-world low-grade water matrices, demonstrating high Faradaic efficiency, low overpotential, and operational durability over extended periods. Our findings lay a framework for the next generation of water electrolyzers capable of operating efficiently in non-ideal conditions, with direct implications for decentralized hydrogen production, wastewater valorization, and coastal energy systems. By advancing selective anode design, we move closer to a truly scalable and sustainable hydrogen economy that is not constrained by water purity.

After 4500 million years running an optimization algorithm, nature chose to produce hydrogen from the water splitting - photosynthesis - but not to store it or use it as such; Nature chose to produce and transform hydrogen into energy-carrying biomolecules and into biomolecules used to build biological structures. Hydrogen, under ambient conditions, has a low energy density and must be compressed or liquefied to be used as an energy vector, that is, as a substrate for energy transport and storage. At 700 bar, hydrogen exhibits an energy density of 1.3 kWh L^-1, and the compression process requires the equivalent of ca. 13 % of the energy of compressed hydrogen (thermodynamic energy is 6.7 %, assuming isothermal compression, and 10.5 % for adiabatic compression); Liquefied hydrogen has an energy density of 2.3 kWh L^-1, and the liquefaction process requires the equivalent of ca. 36 % of the energy of liquefied hydrogen. Hydrogen is then a bad energy vector, but a very relevant intermediate reagent. Hydrogen should be produced and consumed locally, as Nature realized millions of years ago.

The reaction of methane splitting is:

CH₄ ⇌ C (s) + 2H₂, ∆H⁰ = 75.3 kJ/mol

and produces decarbonized hydrogen and carbon. Intermediate-temperature catalytic methane splitting (IT-CMS) is probably the most efficient and low-cost process for this reaction. If NG is used as a feedstock, it produces decarbonized hydrogen and high-value carbon nanofilament particles with a defined size; if biomethane is used as a feedstock, it produces decarbonized hydrogen, high-value renewable carbon particles, and CO₂ permits. The estimated cost for hydrogen is < 2 € kg^-1 if produced from NG (main assumptions are: NG at 30 € MWh, green electricity at 70 € MWh^-1, CO₂ permits at 70 € kg^-1, graphitic carbon at 1 € kg^-1) and is << 2 € kg^-1 if produced from biomethane (main assumptions are: biomethane at 100 € MWh, CO₂ permits at 70 € kg^-1, graphitic carbon at ≥3 € kg^-1). If hydrogen steam methane reforming (SMR) is replaced by the IT-CMS technology, the world would save 410 Mt y^-1 of CO₂ emissions and 32 000 M€ y^-1 (main assumptions: world’s hydrogen production by SMR of 45.6 Mt y^-1 and hydrogen price, including the required payment of the CO₂ permits, of 2.7 € kg^-1), and if the present entire world’s hydrogen production – ca. 100 Mt y^-1 – were to switch to IT-CMS, the CO₂ emission savings would be ca. 1 Gt y^-1 (ca. 2 % of anthropogenic CO₂ emissions).

The present talk is about this fascinating new technology and when it is expected to be implemented. Also, it will discuss the energy cycle based on direct CO₂ hydrogenation to methanol (load) using biogas, followed by oxy-combustion (unload), using CO₂ as a hydrogen carrier. The first energy cycle has a thermodynamic round-trip efficiency of 89 %.

Proton exchange membrane water electrolysers offer a highly promising route towards producing green hydrogen. Their solid electrolytes and relatively low temperature operation make them particularly amenable to coupling with intermittent renewables. Their long term scale up is constrained by the use of oxides based on scarce precious metals at the anode to drive O₂ evolution. Ruthenium oxide is the most active catalyst, but suffers from poor stabiity. Iridium oxide exhibits improved stability but lower activity. 

In this contribution I will present a series of studies where we have investigated the factors that enable iridium oxide and ruthenium oxide to exhibit superior catalytic performance. Our studies include electrochemical measurements coupled to optical spectroscopy, surface X-ray diffraction, electrochemistry mass spectrometry, inductively coupled mass spectrometry, X-ray absorption spectroscopy and density functional theory. We have investigated the catalysts in multiple forms, from single crystals to commercial catalysts to well defined nanoparticles. We provide a holisitic view of the factors controlling the performance.

MXenes is a family of 2D nanomaterials constituted by the stacking of alternate one-atom thick sheets of an early transition metal with other of carbide or carbonitride. These materials were reported for the first time in 2011 by Barsoum, Naguib, Gogotsi and coworkers¹ and very soon they become favourite materials for supercapacitors and Li-ion battery cathodes. Due to the unique optoelectronic properties and electrical and thermal conductivity, MXenes have also found application as electro- and photocatalysts.² This presentation will describe some of the results that have been recently obtained in our group on the use of MXenes in these two fields.

Regarding electrocatalysis, it will be shown the preparation from commercially available Ti₃AlC₂ in a single step, a Ni-Fe alloy strongly anchored on Ti₃C₂ support using the Lewis acid molten salt (Fig. 1).³ By changing the NiCl₂ to FeCl₂ proportion in the NaCl/KCl eutectic mixture, it is possible to obtain various Ni/Fe atomic ratios. These Ni_xFe_y/Ti₃C₂ samples were tested as anodes for the electrocatalytic oxygen evolution reaction (OER) at neutral pH that is a process occurring in water electrolyzers for hydrogen production. It was found that the Ni₁Fe₁/Ti₃C₂ sample having Ni/Fe atomic ratio of 1 was the best performing OER material exhibiting an overpotential of 310 mV at 10 mA cm^-2, and a Tafel slope of 48 mV dec⁻¹ (Fig. 1).³ DFT calculations suggest that the adsorbate evolution mechanism is more likely than the lattice oxygen mechanism when either Ni or Fe act as the active centers, with higher activity on the Ni sites.

Ni supported on Ti₃C₂ was also used as photothermal catalyst to perform the CO₂ hydrogenation to CH₄ and CH₃OH.⁴ CH₄ and CH₃OH  can be considered as hydrogen carriers and specifically CH₃OH is most wanted liquid organic hydrogen carrier given the high H₂ content and its liquid state at ambient temperature. In this case, it was found that the thin oxide layer of NiO over the core Ni nanopatches establishes a S-heterojunction with the Ti₃C₂ MXene as evidenced by the in situ irradiated XPS (Fig. 2). Fs-TAS reveals an ultrafast charge transfer dynamics in the heterojunction. The combination of the photocatalytic and photothermal effects is demonstrated by determining the influence of the temperature on CO₂ conversion, while the influence of the irradiation wavelength is compatible with the occurrence of photoinduced charge separation (Fig. 2). DFT calculations reveal the important role of Ni metal. Ni oxide and MXene on the adsorption of H₂, CO₂ and CH₃OH formation. Overall, the data that will be materials to establish heterojunctions and Schottky barriers with other semiconductors.

The photocatalytic activity of MXene dots for hydrogen generation and overall water splitting will also be presented.

Green hydrogen is a promising energy vector for many reasons. However, significant challenges remain, particularly regarding its production and practical storage. This contribution focuses on hydrogen storage using Liquid Organic Hydrogen Carriers (LOHCs) as a potential and competitive technology.[1] However, since hydrogen must be reversibly bound into chemical carriers and subsequently released through dehydrogenation, the necessary conversion and reconversion steps inevitably increase the overall hydrogen cost, thereby constraining the industrial appeal of LOHC-based systems. To address this challenge, we propose the development of an integrated long-term energy storage system based on hydrogen derived from biomass through simultaneous electrocatalytic transformations. This strategy enables the direct transfer of hydrogen from biomass to LOHC molecules without the intermediate production of hydrogen gas, while concurrently generating value-added chemical products. In this work, we review the current state of the art in LOHC technologies [2] [3] and our approach for improving the efficiency of hydrogen storage in the liquid form: https://pecaths.eu/


DOI: 10.1021/acs.accounts.6b00474 - Citation: Preuster, P., Papp, C., & Wasserscheid, P. (2017). Liquid Organic Hydrogen Carriers (LOHCs): Toward a Hydrogen-free Hydrogen Economy. Accounts of Chemical Research, 50(1), 74–85.
DOI: 10.1021/acssuschemeng.5c02168 - Citation: Solera-Rojas, J., Forés, C., Beltrán-Gargallo, G., Fabregat-Santiago, F., Mata, J. A., Mejuto, C., & Mas-Marzá, E. (2025). Electrohydrogenation of Benzonitrile into Benzylamine under Mild Aqueous Conditions. ACS Sustainable Chemistry & Engineering, 13(23), 8660–8670.
DOI: doi.org/10.1039/D4GC01275E - Citation: Guenani, N., Solera-Rojas, J., Carvajal, D., Mejuto, C., Mollar-Cuni, A., Guerrero, A., Fabregat-Santiago, F., Mata, J. A., & Mas-Marzá, E. (2024). Room temperature hydrogen production via electro-dehydrogenation of amines into nitriles: advancements in liquid organic hydrogen carriers. Green Chemistry, 26(15), 8768–8776

In this talk, I will discuss recent advances from our laboratory on cuprous oxide (Cu₂O) photoelectrodes for solar-driven chemical transformations. Our work explores several complementary material architectures, including thin-film photocathodes, thin-film photoanodes, and particle-based photocatalysts, all derived from Cu₂O as the light-absorbing semiconductor. This unified materials platform allows us to investigate both reductive and oxidative photochemical processes within a common conceptual framework.

On the reductive side, we study the photoelectrochemical hydrogen evolution reaction (HER) from water, as well as the value-added reduction of organic molecules, where solar-generated electrons drive the synthesis of useful chemical products. On the oxidative side, we examine the oxygen evolution reaction (OER) from water alongside selective oxidation reactions of organic substrates, which offer opportunities for solar-powered chemical manufacturing beyond simple fuel production.

I will begin by describing our approaches to fabricating and modifying Cu₂O thin-film electrodes, including strategies that enable the material to function as either a photocathode or a photoanode despite its intrinsic electronic properties. I will then highlight several representative catalytic reactions that demonstrate the versatility of this semiconductor platform. Finally, I will present recent progress toward translating thin-film photoelectrode concepts into particle-based systems, with the long-term goal of enabling scalable photocatalytic architectures for solar-driven chemical synthesis.

The electrooxidation of glycerol presents a dual opportunity for sustainable chemistry: upgrading a biodiesel byproduct and reducing the energetic cost of some electrolytic processes by replacing the oxygen evolution reaction. Despite this dual benefit, the reaction remains highly complex, with multiple competing pathways and a strong dependence on catalyst composition and operating conditions. In this contribution, we present the recent advances from our group aimed at developing anodic materials suitable for coupling glycerol oxidation with CO₂ electroreduction, following two complementary research lines.

The first line focuses on understanding how electrocatalyst composition and reaction environment influence activity and product distribution. We have examined three representative materials supported on nickel foams: NiCo oxide, AuIn alloy, and PdNi alloy. Electrochemical characterization, combined with in situ UV–vis reflectance spectroscopy, reveals clear differences in the oxidation pathways. Operating conditions also play a significant role. Continuous‑flow experiments show that temperature enhances reaction kinetics, reduces cell potential, and accelerates surface reactivation, helping to mitigate catalyst passivation. Flow rate provides an additional lever to tune residence time, thereby modifying the balance between intermediate and deeper oxidation products.

The second research line explores photoassisted glycerol oxidation using semiconductor electrodes. We have evaluated the electrocatalytic and photoelectrochemical behavior of TiO₂, BiVO₄, and a Bi‑rich graded BiVO₄. Illumination not only decreases the energetic requirements of the process but also alters product selectivity by suppressing the oxygen evolution reaction to a lesser extent than glycerol oxidation. Operating near the OER onset photopotential maximizes faradaic efficiency toward C3 products, particularly in TiO₂, while the Bi‑rich graded BiVO₄ improves charge separation and photocurrent without affecting selectivity.

Overall, these results highlight the importance of integrating catalytic and engineering considerations when designing practical electrochemical systems.

The objective of all stakeholders in the green hydrogen industry (operators, users, government bodies, insurers) is to achieve the highest levels of safety: both in design and engineering, and in operation and maintenance, ensuring that accidents at their facilities are minimized and, consequently, ensuring operational and business continuity.

To this end, it is essential to have a facility design that takes into account the specific characteristics of hydrogen with a comprehensive approach covering everything from storage vessels to inspections, including civil works, containment systems, the selection of sensors, pipework, materials, valves, etc., as well as hydrogen containment and safety features such as non-return valves, flame arresters, zone classification and ATEX components, safety distances, amongst other aspects.

Hydrogen is a critical energy vector for decarbonizing hard-to-abate sectors such as industry, heavy transport, maritime, and aviation. In this context, Moeve positions green hydrogen as a core part of its Positive Motion strategy, with the ambition to become a key industrial enabler of the Iberian and European energy transition.

The ONUBA project in Huelva, Spain, is one of Europe's largest and most advanced industrial green hydrogen developments. Supported by €303 million in European funding and having achieved Final Investment Decision (FID), it is also recognized as an EU Project of Common Interest (PCI). The project will initially deploy 300 MW of electrolysis capacity, forming part of the Andalusian Green Hydrogen Valley, which aims to reach 2 GW. Overall, the full development is expected to require around €1 billion in initial investment and generate over 10,000 direct and indirect jobs, demonstrating that large-scale industry is crucial to transforming hydrogen from a concept into reality.

The presentation will highlight the role of industrial stakeholders in moving green hydrogen from concepts/small-scale demonstrators to widespread implementation. It will highlight how such actors facilitate scalability, enhance technological competitiveness, and ensure production aligns with actual market demand. Specifically, it will examine how a company like Moeve exploits synergies between green hydrogen production and its extensive industrial ecosystem, which encompasses sustainable fuels, chemicals, and energy infrastructure, thereby positioning hydrogen as a key integrating element across these sectors and its business strategy.

Finally, a general strategic overview will be presented to outline requirements for industrial-scale renewable hydrogen projects, including secure access to renewable electricity, grid connection capacity, and long-term supply frameworks. It will also assess the technological and project-level challenges of green hydrogen production, the role of innovation within the company, and the development of resilient industrial ecosystems that support a competitive, scalable green hydrogen future in Europe.

Matteco is a materials technology company focused on new solutions to decarbonize the economy and help build a better future. Our first innovation is a patented high performance catalysts and electrodes for green hydrogen production, that greatly reduce energy consumption (lower opex) and increase current densities (lower capex) in alkaline and AEM electrolysis. Our technology helps make green hydrogen cost competitive, to contribute to the fight against climate change. Today we have a portfolio with our Anode being integrated in pilots in Europe and Asia and the cathode being developed thanks to the EIC-Transition program

We are based in Valencia, Spain, and are a part of Zubi Group. We are expanding our manufacturing capacity to reach GW-scale.

I am currently Chief Operating Officer at Matteco, where I oversee the company's support functions including Finance, IT, Strategic Projects, and core Operations. As a member of the executive committee and key steering forums, I contribute to corporate governance, strategic planning, and execution.

The sustainable production of hydrogen through photoelectrochemical processes represents a key strategy for the development of solar fuels. In this work, we investigate the role of silver (Ag) nanocorals as cocatalysts on CuBi₂O₄ photocathodes for the hydrogen evolution reaction (HER). CuBi₂O₄ photocathodes were fabricated by electrodeposition and extensively characterized using electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray absorption techniques, confirming their tetragonal structure and stoichiometric composition.

Ag nanocorals were deposited by physical vapor evaporation, resulting in a homogeneous distribution of nanoscale domains on the semiconductor surface. The Ag-modified photocathodes exhibited a significant enhancement in photocurrent density under simulated solar illumination compared to bare CuBi₂O₄ photocathodes. Electrochemical impedance spectroscopy (EIS) revealed a decrease in charge transfer resistance and reduced carrier accumulation at the semiconductor–electrolyte interface.

Furthermore, steady-state and time-resolved photoluminescence (PL), together with transient absorption spectroscopy (TAS), demonstrated suppressed electron–hole recombination and prolonged carrier lifetimes in the presence of Ag. These results indicate that silver acts as an active cocatalyst, promoting efficient charge separation and extraction rather than merely passivating surface states.

Then, this study provides mechanistic insight into the role of Ag nanocorals in CuBi₂O₄-based photocathodes and demonstrates that their incorporation constitutes an effective strategy to improve photoelectrocatalytic performance. The proposed system emerges as a promising candidate for solar-driven hydrogen production and other photoelectroreduction reactions.

By virtue of its high volumetric energy density, well-defined distribution infrastructure and the possibility to obtain CO_x-free hydrogen (H₂) from its decomposition, ammonia (NH₃) is considered a key energy carrier in future neutral-carbon energy systems. Unfortunately, the use of this carrier has been limited by the absence of an efficient NH₃ decomposition process. Photo-thermal catalysis, a hybrid approach that combines both thermal and non-thermal contributions of light, has showed a great potential to drive chemical reactions using sunlight as unique energy source. Among others, MOF-derived materials have recently appeared as promising candidates for applications in photo-thermal catalysis due to their broad light absorption, effective light-to-heat conversion and well-dispersed metal active sites. Here, we demonstrate the use of MOF-derived photo-thermal catalysts to perform the NH₃ decomposition reaction at low temperatures and high conversion rates.

Catalysts were obtained from the controlled pyrolysis under inert atmosphere of different Fe- and Co-based MOF precursors. The photo-thermal NH₃ decomposition was performed under continuous flow configuration using a commercial reaction chamber equipped with a quartz window. At high space velocities in the order of 20000 mL g^-1 h^-1, the catalysts reached a temperature of 250 °C and a 25 % NH₃ conversion, which translated into a H₂ production rate as high as 326 mmol H₂ g^-1 h^-1. Additional blank experiments under dark conditions displayed negligible NH₃ decomposition rates, thus indicating that the synergy between light and heat is crucial to enhance the catalytic activity towards NH₃ conversion. In fact, mechanistic experiments including irradiance-dependent catalytic tests and photo-current measurements demonstrated the cooperative effect between thermal and non-thermal effects in the system. DFT calculations also suggested that the combination of high temperatures and photo-generated carriers under illumination prevented the formation of a thermodynamic sink, thus facilitating the reaction rate compared to dark conditions. To the best of our knowledge, this is the first example of the use of  MOF-derived catalysts for the efficient photo-thermal NH₃ cracking reaction under continuous flow configuration.

The large‑scale deployment of low‑carbon hydrogen systems is expected to intensify interactions between renewable electricity, hydrogen production, and carbon management strategies. In this context, carbon capture and utilisation (CCU) is increasingly discussed as a pathway for carbon recycling and, in the longer term, as a potential component of hydrogen‑integrated energy systems. However, most CCU experimental infrastructures remain site‑specific and operate under relatively stable and idealised conditions, limiting their ability to capture the spatial and temporal variability that characterises real industrial environments.

This talk presents a project focused on the design and deployment of mobile CCU pilot plants conceived as versatile experimental. Set in Catalonia—home to one of the largest industrial hubs in southern Europe and currently undergoing a transition towards industrial electrification and circular resource use—the project aims to support energy‑intensive industries facing urgent CO₂ reduction challenges on the path to climate neutrality by 2050. The mobile pilots, with a capture capacity of approximately 250 kg CO₂ per day, will enable on‑site testing across heterogeneous industrial emission sources.

By operating the same pilot units across multiple locations, the project will allow systematic investigation of how real‑world CO₂ variability—such as fluctuating flow rates, changing impurity profiles, and transient operating conditions—affects CO₂ capture, separation, and utilisation performance. Four different CCU technologies are integrated into the mobile platforms, providing a common experimental basis to assess innovative materials, catalysts, and process configurations at an advanced pre‑industrial stage. The resulting datasets are intended to inform kinetic modelling, reactor design, techno‑economic assessment, and life‑cycle analysis, while supporting the progression of capture technologies from TRL 4–5 to TRL 6–7.

Beyond its technological objectives, the project implements an open, modular innovation model that fosters public‑private partnerships, promotes social engagement, and helps bridge the technological valley of death. In the longer term, such experimental infrastructures may also enable systematic studies of CCU integration with low‑carbon hydrogen systems, supporting more robust system‑level assessments of future industrial decarbonisation pathways.

Hydrogen is a key energy carrier for a sustainable future, as it can be used directly as a fuel and as a precursor in the chemical industry for the production of fuels, solvents, monomers, and other value-added chemicals.

Electrochemical methods enable water splitting, leading to the simultaneous generation of H₂ and O₂. However, the high energy demand of the oxygen evolution reaction (OER) remains a major challenge for the cost-effective production of hydrogen via water electrolysis.

Replacing OER with the electrooxidation of biomass-derived molecules offers a promising strategy to reduce cell voltage and improve process profitability, as it enables the simultaneous production of high-value-added products of industrial interest. In this work, hydrogen production is coupled with the electrooxidation of furans, primary amines, and lignin-derived compounds such as vanillin. These reactions are enabled by nickel-based electrodes, which act as efficient electrocatalysts in alkaline media, where NiOOH species promote selective oxidation at lower potentials.

Beyond electrooxidation, the electroreduction of furans, nitriles, and ketones is also emerging as a promising strategy for the production of value-added compounds without the need for molecular hydrogen.

Overall, these approaches reduce energy consumption while enabling the co-production of value-added chemicals, paving the way for more sustainable and economically competitive hydrogen production systems.

Nanometer-resolved Operando Photo-Response of Faceted BiVO₄ Semiconductor Nanoparticles

Photo(electro)catalysis with semiconducting nanoparticles (NPs) is an attractive approach to convert abundant but intermittent renewable electricity into stable chemical fuels. However, our understanding of the microscopic processes governing the performance of the materials has been hampered by the lack of operando characterization techniques with sufficient lateral resolution. Here, using Atomic Force Microscopy we demonstrate that the local surface potentials of NPs of bismuth vanadate (BiVO₄) and their response to illumination differ between adjacent facets and depend strongly on the pH of the ambient electrolyte. The isoelectric points of the dominant {010} basal plane and the adjacent {110} side facets differ by 1.5 pH units. Upon illumination, both facets accumulate positive charges and display a maximum surface photo-response of +55mV, much stronger than reported in the literature for the surface photo voltage of BiVO₄ NPs in air. High resolution AFM images reveal the presence of numerous surface defects ranging from, vacancies of a few atoms, to single unit cell steps, to microfacets of variable orientation and degree of disorder. These defects typically carry a highly localized negative surface charge density and display an opposite photo-response compared to the adjacent facets. Strategies to model and optimize the performance of photocatalyst NPs therefore require an understanding of the distribution of surface defects, including the interaction with the ambient electrolyte [1-2].

At ReMade@ARI your R&D departments have the possibility of freely accessing Europe's best existing analytical facilities, instrumentation, methods and the know-how to use them for advanced materials characterization in H2 PtX! Together we will realize your idea, and make a substantial impact on the circular economy.

The project provides scientists who are working on the design of new recyclable materials with analytical tools that enable them to explore the properties and the structure of their material in smallest details up to atomic resolution. ReMade@ARI commits to leverage the development of innovative, sustainable materials for key components in the most diverse sectors, including the immerging Hydrogen Industry, on an unprecedented level. It continues to be the central hub in Europe for all sectors and research areas in which new materials for a circular economy will be developed.

Specific examples will be shown from the world leading neutron reseach facility, the Institut Laue Langevin in Grenoble, France. The benefits of such advanced instrumentation leading to the obtention of experimental data, coupled and compared with theoretical simulation activities, will be given. For instance, combined, operando and high resolution small-angle neutron scattering (SANS) and neutron imaging (NI) provide unique and complimentary in-situ local water distribution profiles in operating Hydrogen PtX fuel cells. The results reveal the formation of significant in and through-plane H2O gradients as a function of operating parameters, from nanometer to micrometer scales, and in real-time [1]. These findings, augmented by the investigation of new, more environmentally friendly proton exchange membranes, highlight the intra-cellular complexity of gaseous and fluid flow, and how these essential factors affect functionality, leading to improvements in efficiency and overall cell performance of commercial cells.

SUNERGY is a pan-European R&I initiative working to enable a circular economy through the sustainable production of fossil-free fuels and commodity chemicals from renewable energy (sunlight, wind) and abundant molecules (CO₂, water, nitrogen). The approach is based on scientific breakthroughs tightly coupled to scale-up by increasing the technological readiness of renewable conversion technologies for the large-scale sustainable manufacturing of hydrogen, synthetic hydrocarbons, and ammonia. It builds on an open community of currently 300+ supporters from industry, academia and society, across sectors, and geographical areas.

SUNERGY has been supported in its activities by the Horizon Europe SUNER-C Coordination and Support Action (CSA, Grant Agreement N°101058481, June 2022 à May 2025), covering both fuels produced via indirect processes (e-fuels, thermochemical processes) and direct solar fuels (direct conversion of solar energy to chemical energy, i.e., artificial photosynthesis). A new CSA project, SUN2X-SET, is expected to begin its activities in May 2026 for a duration of two years. This project will focus more on Direct Solar Fuels with the main objective of continuing the activities under the umbrella of the Strategic Energy Technology Plan (SET Plan). 

The contribution will introduce the SUNERGY initiative, the main achievements of the SUNER-C project and the SUN2X-SET project taking into account the current context and policies on hydrogen, CCU and sustainable fuels and chemicals.

Hydrogen is emerging as a key element in Spain's energy transition strategy, aligning with both European decarbonization goals and national efforts to achieve climate neutrality by 2050. As a clean and versatile energy carrier, hydrogen has gained attention as one of the feasible and potential solution to decarbonize hard-to-abate sectors such as heavy industry, transportation, and long-term energy storage. Spain's favourable geographic conditions, including abundant solar and wind resources, position the country as a competitive producer of green hydrogen, generated through electrolysis powered by renewable energy.

The Spanish government has taken decisive steps to promote hydrogen development, particularly through its "Hydrogen Roadmap: A Commitment to Renewable Hydrogen," approved in 2020 and reviewed in 2024. This roadmap sets ambitious targets for 2030, including the installation of 12 GW of electrolyser capacity, the deployment of hydrogen refuelling stations, and the integration of hydrogen within different industrial processes.

Challenges remain, particularly in scaling up infrastructure, reducing costs, and creating a regulatory framework that ensures market competitiveness and safety. However, with strong political support, technological advances, and growing key collaborations, Spain is well-positioned to become a leader in the European hydrogen economy.

This abstract provides a concise overview of the current state, policies, opportunities, and challenges of hydrogen development in Spain, emphasizing its strategic role in the broader context of energy transition and sustainability.

This keynote aims to review the National plans to develop and deploy the hydrogen economy, based on the objectives defined for 2030 and 2050 to reach net zero emissions. Current ongoing projects are explained, as well as the different funding schemes used to deploy the solution within different industries to be decarbonized, both as an energy vector and as an industrial raw material.

Finally, the future European and National challenges are mentioned, with the aim of being able to meet the fixed objectives to achieve the complete decarbonization of the economy to reach a net zero emissions by 2050.

Key words: Hydrogen, green hydrogen, renewable energies, decarbonization, Zero emissions, electrolysis, fuel cells, applications, strategy, roadmap, Europe, Spain, Challenges.

Hydrogen will play a key role on the energy transition towards a more sustainable society worldwide. However, there are still several challenges to be resolved. 

At the CDTI Innovation, we support, with public funding, the development of technology with the goal of having companies bring new products to the market, promoting business growth and a positive impact on society.

This presentation will provide a general overview of the different funding opportunities offered by CDTI for R&D projects related to the entire hydrogen value chain, with examples of projects funded in the past.

Oxygen electrocatalysis plays a central role in green hydrogen production and utilisation, yet significant challenges remain in understanding and controlling activity, stability, and selectivity under operating conditions. Tailoring the structure of the electrochemical interface is key to establishing structure-property relationships and elucidating reaction mechanisms in electrocatalysis [1]. Fundamental studies on well-defined electrified interfaces provide essential insights into the factors governing oxygen reduction [2] and evolution reactions (ORR and OER), particularly in acidic media relevant to proton exchange membrane fuel cells and water electrolysers.

In this talk, I will present strategies to probe and engineer the electrode–electrolyte interface, focusing on the role of the electric double-layer structure and electrolyte composition. I will discuss our work on platinum-based catalysts for ORR and iridium-based nanostructured catalysts for OER [2-4], highlighting the influence of electrolyte anions and pH on catalytic performance. I will also address the importance and challenges of accurately assessing the electrochemically active surface area (ECSA) [5]. Finally, I will show how concepts derived from oxygen electrocatalysis can be extended to emerging electrochemical oxidation reactions, such as methane conversion [6], where controlling the interface is key to achieving selective transformations, thereby bridging green hydrogen production with next-generation electrochemical processes.

References

[1] P. Sebastián-Pascual, A. Herzog, Y. Zhang, Y. Shao-Horn, M. Escudero-Escribano, Nature Catalysis 2025, 8, 986.

[2] M. Escudero-Escribano et al., Science 2016, 352, 73.

[3] A.W. Jensen et al., Journal of Materials Chemistry A 2020, 8, 1066.

[4] J.A. Arminio-Ravelo, A.W. Jensen, K.D. Jensen, J. Quinson, M. Escudero-Escribano, ChemPhysChem 2019, 20, 2956.

[5] J.B.V. Mygind, M. Rost, M. Escudero-Escribano, ACS Energy Letters 2026, 11, 2508.

[6] J.A. Arminio-Ravelo, S. Favero, M. Escudero-Escribano, ACS Energy Letters 2025, 10, 4842.

TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD TBD

The transition to a hydrogen-based energy economy requires catalytic materials that not only enable efficient green hydrogen production, but also leverage hydrogen as a sustainable chemical feedstock. Achieving this goal demands mechanistic insight, physically meaningful descriptors, and computational strategies that operate under realistic electrochemical conditions.

In this talk, I will discuss how reaction mechanisms and activity descriptors can guide the rational design of catalysts for both hydrogen evolution–coupled processes and hydrogen utilization reactions. Using the oxygen evolution reaction (OER) as a representative case, I will illustrate how scaling relations and mechanistic trends across molecular and heterogeneous catalysts can be embedded into automated computational workflows to accelerate the discovery of cost-effective materials for water electrolysis.[1–11]

I will then highlight the importance of modeling electrified solid–liquid interfaces under operando conditions. In electrochemical hydrogenation (ECH), the distribution and binding strength of surface hydrogen govern selectivity and determine competition with the hydrogen evolution reaction (HER).[12,13] By tailoring hydrogen surface coverages and interfacial properties, it is possible to promote selective hydrogenation in alkaline media using earth-abundant metals, offering a pathway to couple renewable hydrogen generation with sustainable chemical synthesis.

Overall, this work demonstrates how integrating mechanistic understanding, descriptor-based screening, and operando-aware modeling enables the rational design of catalytic systems for both hydrogen production and hydrogen-driven transformations.

The global energy landscape requires the development of sustainable energy production sources capable of replacing finite fossil fuels and reducing environmental problems. Renewable energies are currently in use; however, their intermittency makes it necessary to convert them into energy vectors suitable for long-term storage. The production of hydrogen from water using sustainable processes, such as photocatalysis or electrocatalysis powered by an external source of renewable electricity, is believed to be a promising solution. Unfortunately, most active catalysts capable of carrying out these transformations are based on expensive precious metals. Therefore, the design of highly active, stable, and precious metal-free photocatalysts and electrocatalysts is of utmost importance for the energy transition.

In this regard, molybdenum sulfide-based materials have emerged as potential precious metal-free candidates towards hydrogen evolution reaction (HER). Bulk molybdenum disulfide (MoS₂) shows low activity in HER because its activity originates mainly at the edge sites, while the basal planes are catalytically inert. Generally, most strategies used to improve the activity of MoS₂-derived catalysts have focused on the nanostructuring of these materials to maximize the exposure of active edge sites. Nevertheless, the most convenient approach to achieve this goal should involve the activation of basal planes by defect engineering.

Recently, we have established an innovative bottom-up synthetic strategy that uses Mo₃S_4-7 molecular cluster complexes as precursors to engineer defective molybdenum sulfide nanomaterials (called {Mo₃S₄₋₇}_n) with a greater number of defects in both the edge positions and the basal planes and, therefore, with higher activity. Remarkably, the unique structural configuration of these subunits has made it possible to obtain advanced heterogeneous catalysts for hydrogenation and dehydrogenation reactions in fine chemical synthesis.^[1,2,3] In this communication, it will be shown how, thanks to the extended molecular nature of the {Mo₃S₄₋₇}_n nanomaterials and their processability in the form of heterojunctions with conductive carbon supports and inorganic semiconductors, highly active HER electrocatalysts and photocatalysts have been obtained, respectively.^[4]  Furthermore, the ability to adjust the composition of the molecular cluster precursor allows the derived materials to be precisely tuned and, therefore, the nature of the HER active sites to be deciphered.

Electrocatalysis has emerged as a promising process to store renewable energy into fuels, such as green H₂, and high added-value chemicals to decarbonise the energy and fine chemical sectors. In the H₂ evolution, the oxygen evolution reaction (OER) is the process bottleneck due to its slow reaction kinetics, especially when using Earth-abundant metal oxide catalysts. The efficiency of these catalysts does not only depend on the nature of the metal oxide, but also on their physical characteristics such as composition, magnetic susceptibility, and chirality, as well as the transient behaviour and cooperativity between active sites. However, the influence of some of these catalysts characteristics in the OER mechanism and kinetics remains elusive. Obtaining such detailed mechanistic and kinetic knowledge requires the use of in-situ and operando spectroscopic techniques that can probe the system under operating conditions.

In this talk, I will discuss cooperativity between active sites in different NiFeOx anodes for OER and glycerol oxidation.¹ Such cooperativity effects have recently been reported to lead to different surface coverage of active sites,² leading to changes in the OER mechanism. I will also be discussing how external magnetic fields³ or the intrinsic chiral nature,⁴ taking advantage of the chiral induced spin selectivity effect, of a NiFeOx anode influence such cooperativity and lead to enhanced OER kinetics.

Hydrogen generated via water electrolysis is a cornerstone of emerging low-carbon energy systems. Replacing critical noble metals such as Pt with earth-abundant alternatives is essential for sustainable and scalable hydrogen technologies. Molybdenum disulfide (MoS₂) is a promising catalyst for the hydrogen evolution reaction (HER) [1]. Its performance can be enhanced considerably by doping and nano-structuring of the material. However, the aimed development of a competitive catalyst is limited by an incomplete understanding of adsorption and transport processes.

In this work, quasi-elastic neutron scattering (QENS), neutron spin-echo (NSE) and inelastic neutron spectroscopy (INS) are combined with X-ray techniques (XPS, XRD and EDX) to elucidate hydrogen and water dynamics in pristine, electrochemically activated and chemically doped MoS₂ nanopowders. Electrochemical activation and doping with nitrogen or cobalt provide scalable modification routes to engineer defect density and surface chemistry [2, 3].

Our neutron measurements reveal distinct dynamical regimes across multiple time and length scales. In pristine MoS₂, hydrogen species exhibit in-plane diffusion, while recombined molecular hydrogen shows enhanced diffusion. INS identifies vibrational signatures of S–H bonds and interfacial water, whose intensities increase after electrochemical activation, indicating enhanced surface hydrogenation. Nitrogen incorporation and cobalt addition generate defect-rich environments that significantly impact hydrogen diffusion, consistent with modified adsorption energetics and improved catalytic functionality.

By directly correlating atomic-scale hydrogen motion with chemical modification strategies, this work provides fundamental insight into transport mechanisms governing HER activity. The results demonstrate how advanced neutron techniques enable sustainable materials development for hydrogen production, supporting resource-efficient and low-carbon energy infrastructures.