Symposium FC
Materials and Process Innovation for Hydrogen Production and Storage
ABSTRACTS
Session FC-1 Hydrogen Production
FC-1:IL01 Foam-structured Membrane Reactor Technology for Low-emission Hydrogen Production
A. IULIANELLI, CNR-ITM, Rende (CS), Italy
In the transition from a carbon-based to a sustainable hydrogen economy, the European Clean Hydrogen Partnership agency is promoting research and innovative technologies on decarbonised hydrogen generation by the exploitation of renewable sources, as an alternative to fossil fuels. Membrane reactors may play a strategic role in the field of zero-net strategy, as they constitute an intensified solution presenting several benefits over the conventional processes to generate low impact carbon emissions hydrogen through biogas reforming. This work deals with the recent developments on foam structured membrane reactors to generate decarbonised hydrogen with the intent of meeting the strict targets of the European Clean Hydrogen Partnership. Furthermore, a pioneeristic design and development of an electrically-driven foam structured membrane reactor will be presented, outlining the benefits of an electricity-to-heat (Joule heating) assisted membrane reactor in terms of depletion of collateral CO2 emissions (conventionally due to the fossil fuel combustion heating), and higher energy efficiency, over other competing technologies.
FC-1:IL02 Steam Reforming Using Biomass: A Very Effective Process for Hydrogen Production
D. STEVANOVIĆ, HiTES Holding GmbH, Sulzbach-Rosenberg, Germany
The initial enthusiasm for hydrogen in the EU has waned, primarily due to the high production costs of electrolysis. As a promising alternative, biomass-based hydrogen production via allothermal steam reforming has gained attention. This process employs highly preheated steam at 1200 °C, which fulfills multiple roles: it acts as an energy carrier, a gasification medium, and the principal source of hydrogen molecules. Despite the surplus of steam, which enables a high hydrogen concentration in the syngas, there is no need for partial combustion of biomass in the reactor. The so-called tail gas from the PSA unit—unsuitable for further hydrogen recovery but rich in chemical heat—can be combusted in an oxy-fuel process. This enables effective CO₂ removal, thus rendering the entire process not carbon neutral but negative. Unlike classical gasification, this method allows for efficient tar removal and destruction. Detailed mass and energy balances confirm its effectiveness. Cost assessments, show that hydrogen generation costs under German conditions are several times lower than those of electrolysis. While waste biomass availability in the EU may not suffice to meet all future hydrogen demands, it offers a straightforward and cost-effective entry point into the hydrogen economy.
FC-1:IL03 Hydrogen Production from Water using the Sun via Photocatalytic Processes
C. MARCHAL, L. HAMMOUD, C. MARY, T. COTTINEAU, V. KELLER, ICPEES, Institute of Chemistry and Processes for Energy, Environment and Health, UMR 7515, CNRS/University of Strasbourg, Oberschaeffolsheim, France
Photocatalysis is a promising way to produce hydrogen from renewable energy sources. Indeed, the water dissociation (water-splitting) highlighted by Fujishima and Honda in a photoelectrocatalytic cell [1] opened a promising way to produce hydrogen from light energy. Since, many efforts have focused on the development of the water-dissociation in photo-electro- and photo-catalytic systems. However, nowadays, working in photoelectro- or photo-catalytic configuration requires to overcome some limitations to be able to transfer these processes to larger TRL levels. Amongst the challenges to overcome, the elaboration of semiconductive nanomaterials able to absorb visible-light wavelengths, to transfer efficiently the photogenerated charges, to adsorb the reactants and to undergo the desired surface redox reactions, while keeping high stability of their performances under UV activation, remain blocking points. For that purpose, different strategies can be considered and investigated: - Synthesis of stable, non-expensive semiconductors with narrow band-gap. - Chemical doping (cationic, anionic, co-doping) approaches of wide band-gap semiconductors. - Heterojunction formation between wide-and narrow band-gap semiconductors for visible-light harvesting and enhanced charge carrier separa
FC-1:L04 Operando X-ray Absorption Spectroscopy Unveils Light-driven Redox Dynamics at the Semiconductor/Cocatalyst Interface
R. MAZZARO1, A. PICCIONI1, M. SALVI1, P. VECCHI1, M. MAZZANTI2, S. CARAMORI2, F. BOSCHERINI2, L. PASQUINI1, 1Department of Physics and Astronomy, Alma Mater Studiorum - Università di Bologna, Bologna, Italy; 2Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Ferrara, Italy
Cobalt-based mixed oxides are widely studied as oxygen evolution reaction (OER) catalysts, yet their role as photoelectrochemical cocatalysts remains debated due to the lack of operando studies. Here, we unveil redox dynamics of cobalt–iron oxide (CoFeOx) cocatalysts in semiconductor photoanodes for solar water splitting. Combining operando x-ray absorption spectroscopy (XAS) with fixed-energy x-ray absorption voltammetry (FEXRAV) at semiconductor/cocatalyst interfaces, we provide an element-selective probe of Co oxidation states under dark and illuminated conditions. Our results reveal a previously unrecognized interfacial Co state, underscoring interface structure’s role in tuning catalytic activity. We observe light-induced reduction in oxidation state and cathodic shift in Co redox potentials, offering insights into hole transfer and catalytic behavior. Identification of a specific photocatalytic cycle, distinct from dark-state electrocatalysis, advances understanding of how light modulates rate-determining steps in OER. These findings highlight the power of operando x-ray techniques in elucidating interfacial charge transfer and guiding design of more efficient photoelectrochemical systems.
R. Mazzaro et al, Science Advances 11, eadx8089 (2025).
FC-1:L05 Co-doped Zinc Indium Sulfide Nanosheets for Simultaneous Photocatalytic Hydrogen Production and Furfuryl Alcohol Oxidation
H.-W. TANG, JIH-JEN WU, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
Replacing the oxygen evolution reaction in photocatalytic water splitting with a thermodynamically more favorable oxidation reaction has attracted increasing attention as an effective route to achieve simultaneous hydrogen evolution and value-added chemical production. Furfuryl alcohol, a key derivative of biomass processing, can be selectively oxidized to furfural—a vital platform molecule and precursor for numerous industrial chemicals. In this work, we demonstrate a photocatalytic system for the concurrent hydrogen evolution reaction (HER) and furfuryl alcohol oxidation using cobalt-doped zinc indium sulfide (Co-ZnIn2S4, Co-ZIS) nanosheets. Co-ZIS photocatalysts with varying Co concentrations were synthesized via a hydrothermal method. Structural and compositional analyses confirm that Co atoms successfully substitute Zn sites in the ZIS lattice. The optimized Co-ZIS exhibits HER and furfural yields approximately nine times higher than those of pristine ZIS under visible-light irradiation. The photocatalytic mechanism underlying the coupled HER and furfuryl alcohol oxidation over Co-ZIS will be discussed in detail in the presentation.
FC-1:L06 Unveiling the Photocatalytic Potential of BiAgOS Solid Solution for Hydrogen Evolution Reaction
O. BEN ABDELHADI1,2, M. EL KASSAOUI2, H. MOATASSIM2, A. KOTBI1, M. BALLI3,4, O. MOUNKACHI2,5, M. JOUIAD1, 1Laboratory of Physics of Condensed Matter (LPMC), University of Picardie Jules Verne, Scientific Pole, Amiens, France; 2Laboratory of Condensed Matter and Interdisciplinary Sciences, Physics Department, Faculty of Sciences, Mohammed V University in Rabat, Morocco; 3AMEEC Team, LERMA, International University of Rabat, Parc Technopolis, Rocade de Rabat-Sale, Morocco; 4Department of Mechanical Engineering, Faculté de Génie, Université de Sherbrooke, Québec, Canada; 5Institute of Applied Physics, Mohammed VI Polytechnic University, Hay Moulay Rachid, Ben Guerir, Morocco
The growing emphasis on green energy has spurred momentum in research and development within the field of photocatalytic materials, particularly for green hydrogen production. Among the most abundant oxides on Earth, oxychalcogenides stand out for their cost-effectiveness and ease of synthesis. In this context, we present an investigation on the potential use of BiAgOS as an efficient photocatalyst for hydrogen generation. Utilizing density functional theory and ab initio molecular dynamics (AIMD) simulations, we computed its physical properties and assessed its photocatalytic performance. Specifically, using Heyd–Scuseria–Ernzerhof corrections, our calculations yielded an appropriate electronic gap ~1.47 eV necessary for driving the water splitting reaction. Additionally, we obtained a very high optical absorption coefficient ~ 5∙105/cm–1 and an estimation of hydrogen generation yield ~ 289.56 µmol∙g–1. These findings suggest that BiAgOS holds promise for enabling the development of cheap, reliable, and highly efficient photocatalysts for hydrogen production.
FC-1:IL07 Machine Learning-based Models and Simulations for Accelerated Discovery of Thermochemical Water-splitting Media
M. WITMAN1, A. AMBROSINI1, S. BISHOP1, T. DOUGLAS1, E. HECHT1, K. JI1, S. LANY2, A. MCDANIEL1, K. KING1, A. ROWBERG3, V. STAVILA1, J. SUGAR1, M. SYRIGOU1, J. VARLEY3, 1Sandia National Laboratories, Livermore, CA, USA; 2National Renewable Energy Laboratory, USA; 3Lawrence Livermore National Laboratory, USA
Thermochemical hydrogen (TCH) via water-splitting provides a promising technology pathway for hydrogen production since it (in contrast to electrolysis) does not depend primarily on redirecting electricity from the grid for fuel production. Especially due to recent commercialization efforts, 2-step thermal redox cycles in non-stoichiometric metal oxides are of particularly high interest for this pathway; however, state-of-the-art (SOTA) CeO2 has several practical limitations, which has motivated continued materials discovery efforts in this field. Our first contribution demonstrates how machine learning models can accelerate the high-throughput screening of metal oxides’ oxygen defect thermodynamics to identify promising novel TCH candidates. Upon their experimental validation, some materials exhibit TCH capabilities superior to CeO2 under certain reactor operating conditions. Shifting gears, we then discuss how liquid metal-mediated thermochemical redox can serve as a promising alternative approach due its drastically reduced operating temperatures. Here, machine learned interatomic potentials are instead utilized, accelerating the molecular dynamics simulations needed to understand the phenomena and design rules underpinning their excellent water-splitting capabilities.
FC-1:IL08 Lower Temperature and Higher Conversion Thermochemical Hydrogen Production Machine Learned Compounds
S.R. BISHOP1, M.D. WITMAN2, K.A. KING2, A.L. CLAUSER2, M. SYRIGOU2, A. ROWBERG3, J. VARLEY3, T.C. DOUGLAS1, S. LANY4, J.D. SUGAR2, T. OGITSU3, A.H. MCDANIEL2, 1Sandia National Laboratories, Albuquerque, NM, USA; 2Sandia National Laboratories, Livermore, CA, USA; 3Lawrence Livermore National Laboratory, Livermore, CA, USA; 4National Renewable Energy Laboratory, Golden, CO, USA
Thermochemical hydrogen (TCH) production uses high temperature (e.g., from concentrated sunlight) to produce hydrogen using reduction/oxidation of metal oxides. Typically, the metal oxide is heated to high temperature (>1400 °C) causing it to release oxygen, then it is cooled to a lower temperature (~<1000 °C) in steam whereby it re-oxidizes, stripping oxygen from water molecules and producing hydrogen. Due to improved stability, non-stoichiometric oxides that do not change phase during the STCH process are typically used, even though the reversible oxygen content is less than phase changing materials. In this presentation, recent progress in developing and experimentally validating new water splitting materials using a defect Graph Neural Network trained on crystal structures derived from density functional theory will be discussed. An experimental screening protocol used to evaluate predicted materials will be presented. New materials that enable TCH at lower temperatures (<1200 °C) and in high H2 to steam ratios discovered in this project will be discussed.
SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. Part of the work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under contract no. DE-AC
FC-1:IL09 Multi-objective Optimization of Fuel Electrode Microstructure for Cost-effective and High-performance Solid Oxide Electrolysis Cells
H. SALIHI, N. VAZ, KISUNG LIM, JAEYOO CHOI, MINSANG KIM, MYEONGHYEON CHO, SOOJIN AHN, HYUNCHUL JU, Department of Mechanical Engineering & BK21 FOUR Education and Research team for Overcoming Mechanical Challenges in Carbon Neutrality, Inha University, Incheon, Republic of Korea
Solid oxide electrolysis cells (SOECs) offer significant potential for efficient hydrogen production; however, their performance and cost are highly dependent on the microstructure of the fuel functional layer (FFL). This presentation focuses on optimizing both the material composition and microstructural design of the FFL, which comprises nickel (Ni) and yttria-stabilized zirconia (YSZ). The particle sizes of Ni and YSZ influence the active surface area for electrochemical reactions and ohmic resistance, while FFL porosity affects gas transport and electrical conductivity. These parameters not only impact overall SOEC performance but also contribute substantially to raw material costs, as smaller particle sizes typically require more complex and expensive fabrication methods. To address this challenge, a multi-objective optimization framework is employed to investigate the trade-offs between performance and cost, with a focus on Ni and YSZ particle sizes and FFL porosity. The Pareto front analysis delineates a continuum of design strategies, spanning high-performance configurations associated with elevated costs to more cost-effective but suboptimal alternatives. Specifically, the single-objective optimization (SOO) framework prioritizes the minimization of cell voltage, often at the expense of increased fabrication or material costs. A comprehensive voltage decomposition further elucidates the influence of microstructural parameters on activation and ohmic overpotentials, indicating that SOO-driven designs effectively suppress these losses through reduced particle sizes and decreased porosity. Our analysis identifies promising microstructural configurations that enhance SOEC performance relative to a baseline case while simultaneously reducing raw material costs. This strategy provides a pathway toward cost-effective and high-efficiency SOEC technologies for sustainable hydrogen production.
FC-1:IL10 From Design to Device: Integrating 3D Nanostructures for Safe and Efficient Water Electrolysis
A. LAVACCHI, Institute of Chemistry of Organometallic Compounds of the National Research Council (ICCOM-CNR), Sesto Fiorentino (FI), Italy
Green hydrogen is emerging as a key solution for decarbonizing hard-to-abate industrial sectors and heavy-duty transport, in line with the European Union’s Clean Industrial Deal and broader climate goals. Central to enabling its large-scale production are advanced nanostructured materials that drive efficiency and durability in electrochemical systems. In particular, 3D-designed nanoelectrocatalysts for alkaline electrolyte membrane (AEM) electrolysis are at the forefront of innovation, offering optimized architectures that enhance active site accessibility, improve gas and ion transport, and enable elimination or more efficient use of precious and/or critical resources.
These tailored nanoarchitectures represent a paradigm shift in catalyst engineering, where performance is increasingly dictated by rational design at the nanoscale and mesoscale. While the focus remains on maximizing electrochemical performance and scalability, the increasing structural and chemical complexity of these materials calls for a parallel reflection on safety and sustainability. In this context, the Safety-by-Design (SbD) approach offers a proactive framework to consider potential risks, particularly related to nanotoxicology, fromduring the early stages of material development, without compromising technological advancement.
This presentation will highlight recent progress in the design and fabrication of 3D electrocatalysts for AEM electrolysis, discussing structure–property relationships, integration strategies, and the role of SbD in supporting the responsible deployment of next-generation electrolysis technologies.
FC-1:IL11 Insights into Degradation Mechanisms in Solid Oxide Electrolysis Cells under Operation
H.J. CHANG1,2, H. CHOI1, J. HYEONG CHOI1,3, J.-H. LEE1,2, K.J. YOON1, 1Center for Energy Materials, Korea Institute of Science and Technology, Seoul, Republic of Korea; 2Division of Nano Convergence, KIST School, University of Science and Technology, Seoul, Republic of Korea; 3Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea
To ensure long-term stability of solid oxide electrolysis cells (SOECs), it is essential to clarify nanoscale degradation processes under real operating conditions. This study combines in-situ and ex-situ transmission electron microscopy (TEM) to elucidate complementary aspects of interfacial degradation. Ex-situ analyses using precession electron diffraction (PED) and high-resolution TEM revealed oxygen ion accumulation at the LSM–YSZ interface, inducing anisotropic lattice strain, dislocation formation, and nanopore alignment that lead to gradual delamination. In-situ TEM experiments under oxygen-deficient conditions directly captured dynamic structural changes, including interfacial delamination, LSM polycrystallization, and Mn cation migration driven by oxygen vacancy formation. These phenomena collectively destabilize the perovskite lattice and accelerate performance loss. By integrating in-situ and ex-situ observations, we propose a unified mechanism linking oxygen imbalance, strain accumulation, and redox-induced cation migration to interfacial failure. The insights provide guidance for designing oxygen-stable and degradation-resistant SOEC architectures.
FC-1:L12 Multiscale Simulations of Component Degradation in SOECs
B.C. WOOD, TAE WOOK HEO, KYOUNG KWEON, A. ROWBERG, J. KAUFMAN, KAIHUA JI, Lawrence Livermore National Laboratory, Livermore, CA, USA
Hydrogen production via solid oxide electrolysis cells (SOECs) can provide an efficient means of water splitting, but the extreme conditions of service can lead to accelerated component degradation. To this end, our team has been using high-performance computing and multiscale simulations to investigate SOEC materials and performance degradation. I will share results from our simulations of common SOEC component compositions (YSZ, LSCF, GDC) at both atomistic and microstructural scales, focusing on two commonly observed degradation modes: air electrode decomposition and barrier layer penetration. Based on the results, I will discuss when secondary phases can be formed and how these phases can impact expected performance in electrodes and electrolytes. I will also discuss contaminant permeation through barrier layer and which materials factors are most relevant for controlling unwanted mass transport. Finally, I will illustrate how these results provide insight into some of the most important factors that govern stable operation of SOECs.
Work performed under the auspices of DOE by LLNL under Contract DE-AC52-07NA27344.
Session FC-2 Hydrogen Storage and Distribution
FC-2:IL13 Microstructural Insights into Kinetic Mechanisms in Metal Hydrides through Mesoscale Modeling
TAE WOOK HEO, Materials Science Division & Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, CA, USA
Kinetic processes in metal hydrides are both scientifically intriguing and practically important, central to materials science due to their scientific challenges, functionality (e.g., hydrogen storage), and detrimental effects (e.g., embrittlement) across a wide range of practical uses. Many key challenges in metal hydrides research arise from the complex interplay of surface reactions, diffusion, mechanical interactions, and phase transformations, all occurring over a multiple length and time scales. Crucially, these dynamic atomic and molecular processes are strongly influenced by the material’s microstructure. The mesoscale continuum modeling framework provides a unified platform for integrating atomistic parameters—providing high accuracy for nanoscale chemical processes—with continuum approaches that offer greater flexibility and scalability for describing materials at the microstructural level. Here, we demonstrate the development of a comprehensive mesoscale modeling framework incorporating atomistic parameters to assess microstructural effects on kinetic processes in metal hydrides. Representative case studies are presented, including hydrogen/thermal transport, micromechanical responses, and hydride phase formation in polycrystalline Mg-H, Zr-H, and Ti-H systems.
FC-2:IL14 Advancing Circularity: Hydrogen-Storage Materials and Strategic Metal Recovery
YUANYUAN SHANG, E. ALVARES, N. JARAMILLO, P. JERABEK, C. PISTIDDA, Department of Materials Design, Institute of Hydrogen Technology, Helmholtz-Zentrum hereon GmbH, Geesthacht, Germany
Metal recycling strategies are pivotal for achieving a circular economy and ensuring the responsible management of critical resources. Recent research efforts on innovative hydrogen-storage material synthesis have enabled the selective recovery of strategic metals from industrial residues, spent alloys, and end-of-life functional materials. By integrating advanced materials processing techniques and comprehensive multi-method characterization, the work conducted at Hereon facilitates efficient metal hydride synthesis with notably reduced energy consumption and environmental impact. Particular attention is given to preserving the functional properties of metal hydrides while developing scalable processes that align with existing industrial infrastructure. The results presented demonstrate how these novel approaches, developed through European research consortia, can enhance circularity in metal utilization and promote the sustainable manufacturing of next-generation energy technologies.
FC-2:L15 Development of Hydrogen Transportation and Compression using Metal Hydrides
HIROYUKI TANIGUCHI, Mitsubishi Kakoki Kaisha, Ltd. Kawasaki, Kanagawa, Japan, I. YAMAMOTO, Nagasaki University, Nagasaki, Japan
To promote local production and consumption of electricity, technologies are needed to transport and store hydrogen converted from renewable energy with low energy consumption and ease. We have been demonstrated more than 20 times to store, transport, and use hydrogen with tanks loading Ti-Fe alloys. MH tanks are vertically cylindrical. Although the hydrogen filling pressure being less than 1 MPa, their weight and hydrogen storage capacity are almost equal to a gas cylinder. This hydrogen transport method consumes almost no energy because it does not require compression and it is cooled by a fan during storage and heated by exhaust heat from the fuel cell during release. We are also developing a chemical compressor using metal hydride. This compressor uses thermal energy to compress hydrogen. If waste heat is used, it consumes no electricity. With no sliding parts, it is quiet and is expected to be highly durable. We have successfully increased the hydrogen pressure from 1 MPa to 19.6 MPa using steam.
FC-2:L16 Application of Metal@MOS(Metal Oxide Semiconductors) Core-shell Structured Nanoparticles for Sustainable Solar Water Splitting
YEON-TAE YU, Division of Advanced Materials Engineering and Research Center for Advanced Materials Development, Chonbuk National University, Jeonju, South Korea
Semiconductor materials developed for photocatalytic (PC) and photoelectrochemical (PEC) water splitting applications have been widely utilized as potential methods for hydrogen (H₂) production. However, their performance is limited by various problems, but these difficulties can be alleviated if the development of new photocatalysts is successfully completed. Generally, semiconductors are combined with metal nanoparticles or other semiconductors with different band gaps to enhance their photocatalytic properties, a process known as heterojunction semiconductors. There are several types of heterojunctions, such as Schottky, Type 1, Type 2, and Z-scheme. In this study, core-shell nanoparticles are utilized for heterojunction photocatalysts with Schottky and Z-scheme heterojunctions. In this presentation, we introduce in detail how metal@MOS core-shell nanoparticles (e.g., Au@CeO₂, Au@ZnO as shown in Fig. 1 and 2) are useful for enhancing the photocatalytic activity of semiconductors, and their water splitting reaction mechanisms. In addition, the current issues and future research works of heterojunction photocatalysts are discussed.
FC-2:L17 Exploring the Thermodynamics of TiFe-based Intermetallic Hydrides via a Combined Experimental and Theoretical Study
V. FERRETTI, E. PERICOLI, D. VERNA, L. PASQUINI, University of Bologna, Bologna, Italy
One of the main goals of current research on metal hydrides is to establish a clear relationship between composition and hydrogen-sorption thermodynamics. Machine-learning-guided models have been applied to analyze large datasets and identify key correlations, yet several aspects remain unclear. A representative case is AB TiFe-based hydrides, studied since the 1970s for their moderate hydrogenation conditions (below 100 °C and 100 bar). Among the various elemental substitutions explored to improve their properties, our study focuses on TiFe₁₋ₓNiₓ intermetallic hydrides. Their thermodynamics of hydride formation were investigated through calorimetric and volumetric measurements, allowing determination of enthalpy (ΔH) and entropy (ΔS). These parameters exhibited a linear Enthalpy–Entropy Compensation, leading to increased hydride stability with higher Ni fraction. Building on this case study and extending to other substitutions, we aim to interpret hydride thermodynamics from properties of the pure elements and of the host alloy, also via Density Functional Theory and Vibrational Spectroscopy. Understanding these fundamental physical mechanisms can enable a more effective tuning of hydride thermodynamics.
FC-2:IL18 Optimisation of Room Temperature Hydrogen Storage Properties in Ti-V-Cr-Nb-Mo-Fe Multi-element Alloys
C. ZLOTEA1, M. RAHMOUNI1, A. AGAFONOV1, M.D. WITMAN2, V. STAVILA2, 1Univ. Paris-Est Creteil, CNRS, ICMPE, UMR 7182, Thiais, France; 2Sandia National Laboratories, Livermore, CA, USA
Among various hydrogen storage methods, solid-state storage in the form of alloys and intermetallics forming high-capacity hydrides is one of the most promising due to their high volumetric density, reversibility of absorption/desorption cycling, and safety of these materials. However, further research is needed to develop new alloys that meet the requirements for competitive applications. In this context, we are currently studying refractory body centred cubic (bcc) high entropy alloys that are recognised as promising materials for hydrogen storage due to their high capacity and versatile chemistry. Starting from various previously reported materials in the Ti-V-Cr-Nb-Mo compositional space, we report here a novel bcc alloy containing earth-abundant Fe element with enhanced room temperature hydrogen storage properties. The optimised alloy has a maximum gravimetric capacity of 3.4 wt.% at 25 °C and an enthalpy of hydride formation of -34 kJ/molH2, which is one of the lowest values for bcc HEAs reported to date. The reversible capacity of this alloy remains stable at 2.0-2.1 wt.% for 20 cycles at 25 °C. These advances highlight the potential of Fe-containing multi-element alloys as efficient and economical candidates for next-generation hydrogen storage systems.
FC-2:IL19 Latest Developments in the Field of Metal Hydride Applications
J. BELLOSTA VON COLBE, J. PUSZKIEL, J. JEPSEN, Hereon, Geesthacht, Germany
In the frame of the International Energy Association’s Hydrogen Implementation Agreement Task 51, a body of experts is presently developing the field of hydrides for hydrogen storage, compression and transportation, as well as some alternative uses such as in electrochemistry. The latest developments of the scientists in the Task will be summarized, with a focus on improving the usability of hydrides by minimizing the impact of adverse characteristics, such as expansion during cycling, which can lead to overstressing of hydrogen-containing vessels. New applications fields like the usage of hydrides for air conditioning will also be addressed. The purpose of this lecture will be to give an overview of the field as seen by the scientists working at the cutting edge of research.
FC-2:L21 Design, Synthesis, and Characterization of a C14-Laves Phase-Based High Entropy Alloy for Hydrogen Storage
B. EL AALAMI, V. TRABADELO, High Throughput Multidisciplinary Research Laboratory (HTMR), College of Chemical Sciences and Engineering (CCSE), Mohammed VI Polytechnic University (UM6P), Hay Moulay Rachid, Benguerir, Morocco; H. IDRISSI, Institute of Mechanics, Materials and Civil Engineering, IMAP Division, UCLouvain, Louvain-la-Neuve, Belgium; G. ESSER, Y. FILINCHUK, Institute of Condensed Matter and Nanoscience, UCLouvain, Louvain-la-Neuve, Belgium
C14-Laves phase-based high-entropy alloys demonstrate significant promise for solid-state hydrogen storage owing to their outstanding hydrogen-related properties, including rapid kinetics, easy activation, excellent reversibility, and cycling stability. In this study, both the empirical approach and the CALPHAD method were employed to design a non-equiatomic multi-principal element AB2-type C14-Laves phase within the Zr-Ti-Mn-Fe-Mo system. The alloy was prepared via arc melting and its structure was characterized using different techniques such as XRD, SEM, and TEM analyses. The hydrogen storage properties of the alloy were further evaluated through pressure−composition−temperature (PCT) isotherms, absorption capacity and kinetics, absorption/desorption reversibility, and cycling stability. The alloy showed a hydrogen absorption capacity of 1.5 wt.% with excellent reversibility at different mild temperatures (130 °C, 100 °C, and 70 °C), along with outstanding cycling stability, which makes it good candidate for large-scale stationary storage application.
FC-2:IL22 Hydrogen Storage in High Entropy Alloys
M. BARICCO, Department of Chemistry and NIS (Nanomaterials for Industry and Sustainability), INSTM (Istituto Nazionale di Scienza e Tecnologia dei Materiali), University of Turin, Torino, Italy
The increasing request of storage of renewable energies challenges hydrogen as an energy carrier. High-entropy alloys (HEAs), owing to their compositional complexity and structural versatility, have emerged as promising candidates for solid-state hydrogen storage. This work will provide a broad overview on the use of HEAs for hydrogen storage, pointing out the pros and cons. The goal is to contribute, considering some examples, to the understanding of phase-composition relationships in HEAs, supporting the design of next-generation materials for efficient hydrogen storage. The TiV₀.₆Cr₀.₃Zr₀.₃NbMo alloy, characterized by a BCC and minor intermetallic phases, forms a solid solution with hydrogen at 10 bar and a hydride phase above 50 bar, desorbing hydrogen between 328 K and 348 K, with a maximum capacity of 1.2 wt% at 573 K. Furthermore, four equiatomic TiVCr-based HEAs (TiVCrFeTa, TiVCrFeZr, TiVCrCoTa, TiVCrCoZr) were developed using CALPHAD-guided design to achieve dual BCC/Laves microstructures. Experimental analyses confirmed the predicted phases and revealed hydrogen absorption at 294 K and 30 bar, without activation for most alloys. The TiVCrFeZr and TiVCrCoZr alloys, rich in Laves phases (~40%), exhibited the highest capacities (2.3 wt% and 1.6 wt%).
FC-2:IL23 Two Phases in BCC-rich High Entropy Alloys: Crystal Structure and Effect on Hydrogen Storage
J. HUOT, M. MASAELI, G.C. TSOUMOU, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
Recently, high entropy alloys (HEA) have been investigated for hydrogen storage applications. Usually, these alloys are single phase BCC but, upon substitution of elements, a second phase could be present. In this talk we present the effect of substituting an atom with a large atomic radius with an element with a small atomic radius. We selected the compositions TiVZrHfNb1-xFex where x = 0, 0.2, 0.4, 0.6, 0.8 and 1. This substitution was chosen because iron is lighter and cheaper than niobium thus potentially could reduce the cost of the alloy and increases the storage capacity. We found that replacing Nb by Fe has for effect of inducing a Laves phase. The proportion of Laves phases increases with increasing x. The conditions for the appearance of a single phase HEA and C14 have been checked. We also found from neutron diffraction that, in the Laves phase, elements occupy specific atomic positions. A fast first hydrogenation is only possible for alloys with large content of Laves phase. The synergetic effect in a two-phase system was further investigated for the alloy Ti16Zr4V35Cr15Ni10Mn20. We found that the synergy between the Laves phase and the BCC phase is essential for a fast and complete hydrogenation.
FC-2:L24 Interfacial Engineering of Metal Alloys for Hydrogen Storage under Low-purity Conditions
HYUN CHO, JINSEOK KOH, EUN SEON CHO, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea; SHINYOUNG KANG, Lawrence Livermore National Laboratory (LLNL), USA; KOUJI SAKAKI, National Institute of Advanced Industrial Science and Technology (AIST), Japan
Global energy demand continues to rise with population growth, industrialization, and emerging technologies. Hydrogen is expected to play a central role as a versatile energy carrier. To enable its practical use, hydrogen production, storage, and utilization technologies must be closely integrated. While hydrogen can be produced through various routes, purification remains costly, and current storage relies on physical methods requiring extreme conditions such as high pressure or cryogenic temperatures. We aim to develop a solid-state hydrogen storage material that integrates purification and storage in a single system. By coating metal hydrides with gas-selective surface layers, hydrogen can permeate easily while impurities such as CO₂ and CH₄ are effectively blocked. The diffused hydrogen is then stored in metal alloys. Ti-based alloys were selected as the platform for hydrogen storage under low-purity conditions, with engineered protective layers preventing impurity poisoning. The surface-protected alloy demonstrates stable hydrogen absorption even in the presence of CO₂, offering a simplified, energy-efficient, and cost-effective pathway for hydrogen deployment.
FC-2:L25 Graph-Based Machine Learning Framework for Predicting Hydrogen Storage Capacity in Metal-Organic Frameworks
AZZAM ALFARRAJ, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
Hydrogen is a clean and high-energy fuel, yet its safe and efficient storage remains a key obstacle to widespread adoption. Metal–organic frameworks (MOFs), with their high surface area and tunable porosity, have emerged as promising candidates for solid-state hydrogen storage. In this work, we introduce a graph-based machine learning framework for predicting hydrogen uptake in MOFs by integrating spectral graph theory with data-driven modeling. Molecular structures are represented as weighted graphs from which we extract 20 graph-based descriptors—including Laplacian spectral features, degree statistics, and Zagreb indices—that capture both topological and geometric characteristics of the framework. These interpretable descriptors are used to train multiple regression models on a data set of 3300 MOFs from the Cambridge Structural Database. The XGBoost regressor achieved the highest performance in predicting hydrogen uptake, with a coefficient of determination (R2) of 0.737, RMSE of 0.850% wt, and MAE of 0.433% wt for gravimetric uptake (UG); and a coefficient of determination (R2) of 0.698, RMSE of 4.467 g H2/L, and MAE of 3.045 g H2/L for volumetric uptake (UV). Beyond accurate prediction, the framework enables inverse materials design by identifying graph-based motifs that contribute to improved storage capacity. This integration of chemical graph theory with machine learning provides a scalable, interpretable, and computationally efficient pathway for the discovery of next-generation MOFs tailored for hydrogen storage and other clean energy applications.
FC-2:IL26 Research and Development of Metal Hydrides for Thermochemical Hydrogen Compression
K. SAKAKI, V. CHARBONNIER, K. SHINZATO, H. KIM, K. ASANO, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
Based on thermodynamic stability of metal hydride, hydrogen is compressed upon hydrogen desorption reaction of metal hydrides. This thermochemical hydrogen compression can be driven by low-grade waste heat leading to higher energy efficiency. In addition, they have several advantages such as no moving parts, compact, and silence. In hydrogen refueling stations, hydrogen compressors need to compress hydrogen up to more than 80 MPa for refueling into fuel cell vehicles. Therefore, we have tackled the development of metal hydride of (Ti, Zr)(Cr,Mn)2 compounds which compress hydrogen up to 80 MPa at 80℃ using ultra-high pressure PCT up to 100 MPa. However, pressure was not achieved to 80 MPa at 80℃. Then we have investigated the effect of Fe substitution in (Ti, Zr)(Cr,Mn)2 compounds on their hydrogen absorption and desorption pressures. When Mn was substitution by Fe into TiCr1.25Mn0.75, P-C isotherms and heat-driven compression experiments at 80 ℃ indicate that the hydrogen desorption pressure reached 76 MPa. We also tried to formulate an equation to predict the chemical composition to achieve target pressures based on Vegard’s raw and empirical rule for equilibrium pressure and lattice volume. It is confirmed that the obtained equation works well in the wide pressure range.
FC-2:L28 Thermochemical Hydrogen Generation and Compression via Chemical Hydride Hydrolysis
YONGMIN KIM, HYANGSOO JEONG, CHAN KIM, INSEOK LEE, F.A ALVITA THEDA, Center for Hydrogen and Fuel Cell Research, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
Chemical hydrogen carriers provide a promising pathway for compact, high-density hydrogen storage, but their practical use in mobility and stationary systems remains constrained by limitations in efficiency, water use, and regeneration. This study introduces a thermochemical, non-mechanical system for on-site hydrogen generation and compression that leverages solid-phase hydrolysis catalyzed by an environmentally benign acid under elevated temperature and pressure. The exergonic reaction enables efficient water utilization and high-purity hydrogen production with minimal external energy input. Optimized operation achieved high storage density, scalable system pressures, autothermal operation, and suitablility for fuel-cell integration. Prototype-scale experiments demonstrated kilowatt- to tens-of-kilowatts-level output with compact volumetric storage, while a regeneration route for byproducts enhanced overall energy efficiency and recyclability. Techno-economic analysis confirmed the scalability and cost-effectiveness of the approach for decentralized, mobile, and emergency hydrogen supply. This work advances sustainable hydrogen infrastructure by providing an efficient, compact, and compressor-free solution for high-pressure hydrogen production and delivery.
FC-2:L29 Thermochemical Hydrogen Storage of Low-Purity Hydrogen Using Liquid Organic Hydrogen Carriers
S. RAMADHANI, M.C. ARRAHMAN, JOUNGHWAN CHOI, IN SEOP LIM, JOOHYUNG LEE, HYANGSOO JEONG, YONGMIN KIM, Center for Hydrogen and Fuel Cell Research, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
Hydrogen is recognized as a key energy carrier for realizing a carbon-neutral society, yet its storage and transportation remain challenging due to the need for high-pressure or cryogenic systems. Liquid organic hydrogen carriers (LOHCs) offer a safer and more compact alternative by reversibly storing hydrogen through catalytic hydrogenation and dehydrogenation reactions. However, conventional LOHC hydrogenation processes rely on ultra-high-purity hydrogen to prevent catalyst deactivation, which increases system complexity and cost. In this study, a continuous LOHC hydrogenation system is developed for thermochemical hydrogen storage, employing a heterogeneous catalyst that enables the direct use of low-purity hydrogen streams containing impurities such as CO2, CO, CH4, and trace H2S, commonly found in industrial by-product gases. By employing an impurity-tolerant catalyst and optimized reactor configuration, the system achieves selective hydrogen storage and stable performance without prior gas purification. This approach demonstrates a practical route for integrating hydrogen purification and storage into a single thermochemical process, enabling more efficient utilization of industrial hydrogen sources.
FC-2:IL30 Metal-organic Frameworks: Applications for the Hydrogen Economy
P.Á. SZILÁGYI, University of Oslo, Oslo, Norway
Metal-organic frameworks (MOFs) porous crystalline inorganic-organic hybrid materials with tuneable chemistry and textural properties. [1] We have previously demonstrated that the interaction of small molecules [2], metal atoms [3] and metal nanoclusters [4] may result in altering the properties of the guests. This change consequently can be exploited to tune the properties of the guest for particular functions, of which a few examples will be given. MOFs with pore sizes near and below 1 nm (UiO-66, ZIF-8) have been synthesised and functionalised directly or post-synthetically by grafting various functional groups on the organic linker and/or embedding metal nanoclusters in their pores. The samples were screened for their interaction with reactants and electrolytes to uncover the relevant host-guest interactions and their impact on the materials’ function. I will present how to modulate the interaction strength between the MOF hosts and guest molecules for the hydrogen economy.
[1] S. Kitagawa, et al., Angew. Chem. Int. Ed. 43, 2334 (2004). [2] E. Callini, et al., Chem. Sci, 6, 666 (2016). [3] D. E. Coupry, et al., Chem. Commun. 52, 5175 (2016). [4] P. Á. Szilágyi, et al., J. Mater. Chem. A, 5, 15559 (2017). [5] S. Hérou et al., Sci. Reports 14, #14529 (2024)
FC-2:L31 Influence of Hydrogen Ingress and Capture on the Mechanical Properties of Spray formed 2195 Aluminum Alloy
XIAO-XU YANG1, XIAO-YA WANG2, JIAN-TANG JIANG1,3, 1School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, China; 2Institute of Special Environments Physical Sciences, Harbin Institute of Technology (Shenzhen), Shenzhen, China; 3National Key Laboratory of Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin, China
The current research has focused on the hydrogen capturing and its impact on the mechanical properties of spray-formed 2195 (SF2195) aluminum alloy. Microstructure characterization, thermal desorption spectra (TDS) and hydrogen trapping of characteristic microstructure, are used to investigate the generation, migration and trapping of hydrogen. The retention of moisture in the carrier gas is believed to induce high concentration of hydrogen and the amorphous Al2O3 layer within the SF2195 billet, and the local retention of carrier gas brings about pores with the Al2O3 layer on the inner wall. High concentration of hydrogen is captured in the hot-rolled alloy while around 60% of the hydrogen can be eliminated during the solution-quenching. Particles of T1 phase trap large quantity of hydrogen and the high-density dislocations developed from the pre-stretch promote the migration of hydrogen towards dispersoids and precipitates. The presence of hydrogen and Al2O3 layers contribute to the reduced plasticity of SF2195 alloy. The spreading of flattened pores can induce intensified hydrogen damage effect in local regions and thus contribute to the unusually decreased ductility along the thickness direction in the T8 aged alloy.
FC-2:L32 A Modular MgH2 Demonstration Tank to Store Reversibly Hydrogen
H. EL ALEMA1, Z. DJORDJEVIC2, N. SKRYABINA2, D. FRUCHART2, M. HAJJI1, M. BALLI3,4, A. ZAABOUT5, O. MOUNKACHI1,6, 1LAMCSCI, Faculty of Sciences, Mohammed V University in Rabat, Morocco; 2Jomi-Leman SA, La Motte Fanjas, France; 3AMEEC Team, LERMA, International University of Rabat, Parc Technopolis, Rocade de Rabat-Sale, Morocco; 4Department of Mechanical Engineering, University of Sherbrooke, Quebec, Canada; 5Applied Chemistry and Engineering Research Centre of Excellence, Mohammed VI Polytechnic University (UM6P), Ben Guerir, Morocco; 6College of Computing, Mohammed VI Polytechnic University (UM6P), Ben Guerir, Morocco
While solid-state hydrogen storage in metal hydrides has gained significant attention, the performance of built tanks strongly depends on their design, particularly regarding safety, energy efficiency, and heat management. In this work, micro-sized MgH₂ powder activated with additives and mixed with expanded graphite was compacted into stacked capsule-type tanks; two heater configurations were developed and numerically analyzed using ANSYS Fluent, showing that the optimized design ensured efficient heat transfer and accelerated Mg ↔ MgH₂ reactions.
FC-2:IL33 Low-Temperature Hydrogen Release in Novel LiBH4-Based Reactive Hydride Composites
L. WOODLIFFE1, N. HALL1, J. RAMSHAW1, S. CHECCHIA2, D. GRANT1, M. DORNHEIM1, 1University of Nottingham, Nottingham, UK; 2European Synchrotron Radiation Facility (ESRF), Grenoble, France
Safe and efficient hydrogen storage remains a critical bottleneck for the deployment of hydrogen across hard-to-decarbonise sectors. Reactive hydride composites (RHCs) are a next-generation storage solution, offering large hydrogen capacities without high pressures or cryogenic temperatures. They contain mixtures of hydrides which react together, lowering the energy barrier for hydrogen release. However, their practical use has been hindered by slow kinetics, high operating temperatures and poor cyclability.[1] Recently, RHCs containing LiBH4 combined with amides and hydrides have shown promise as highly cyclable systems, operating as low as 100 °C.[2] However, operation temperatures <80 °C are needed to enable fuel cell waste heat to be used for hydrogen release, which would significantly improve system efficiency and cost. In this work, we have developed exciting novel RHCs with hydrogen release starting at temperatures as low as 70-80 °C. The RHCs contain LiBH4 with Mg/Li amides and various metal hydrides. Reaction mechanisms were monitored by heating the samples under synchrotron X-ray diffraction at the European Synchrotron Radiation Facility, and hydrogen release and enthalpy changes were measured using thermogravimetric analysis with differential scanning calorimetry and mass spectroscopy. These results generate new mechanistic insight to support the development of RHCs as a next-generation hydrogen storage concept, utilising waste heat for hydrogen release. This would dramatically improve system efficiency and unlock the deployment of solid-state hydrogen storage towards global net-zero ambitions.
[1] N. Ali et al., Int. J. Hydrog. Energy, 46 (2021), 31674–31698. [2] H. Wang et al., Adv. Energy. Mat, 7.13 (2017), 1602456.
This work was supported by Leverhulme Trust (Grant No. LIP-2021-018)
FC-2:IL34 Complex Hydride-based Fuel Additives for Solid Hydrogen (FLASH) for Electric Aviation Drones
N. LEICK, T. GENNETT, National Renewable Energy Laboratory, Golden, CO, USA; N.A. STRANGE, SLAC National Accelerator, Menlo Park, CA, USA; F. HARRINGTON, A. ARZADON, R. MOEN, C. MOORE, Honeywell International Inc., Charlotte, NC, USA
The advancement of electric aviation in unmanned aerial vehicles (UAVs) demands innovative energy storage systems that extend flight time while maintaining safety and efficiency. Hydrogen (H₂) fuel technologies are emerging as a leading solution, offering high energy density and safety benefits. This presentation focuses on Fuel Additives for Solid Hydrogen (FLASH) materials—an advanced alternative to compressed hydrogen gas. FLASH uses complex hydride-based materials activated thermally to store hydrogen in chemical bonds, enabling stable, ambient-condition storage with controlled on-demand release. This approach not only enhances safety but also significantly extends UAV flight endurance compared to batteries. FLASH systems have demonstrated the potential to achieve 7 wt% hydrogen content and 550 Wh/kg energy density, offering a promising, low-cost, drop-in replacement for current fuel cartridge technologies. By integrating FLASH, UAV platforms can benefit from increased operational range and reduced logistical burdens, marking a key step forward in sustainable electric aviation.
FC-2:IL35 Promotor-controlled Intermediate Dynamics Boost Dehydrogenation of Perhydro-benzyltoluene
HYANGSOO JEONG, YONGMIN KIM, EUI-RIM ON, KIMOON LEE, YEONSU KWAK, CHAN KIM, QUAN DAO, HYUNTAE SOHN, YONGMIN KIM, SUK WOO NAM, Center for Hydrogen and Fuel Cells, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
Hydrogen is increasingly recognized as a next-generation renewable energy carrier due to its exceptionally high gravimetric energy density (33.3 kWh kg⁻¹). Nevertheless, its inherently low volumetric energy density (2.97 Wh L⁻¹ for H₂ gas at 273 K and 1 atm) poses a major challenge to its widespread utilization. For long-distance and large-scale applications, liquefied hydrogen and chemical hydrogen carriers have become the principal means of storage and transportation. Achieving a practical ‘hydrogen economy’ thus requires the development of safe, reversible, and cost-effective systems capable of efficiently storing and releasing large quantities of hydrogen. Among the various options, liquid-phase hydrogen carriers with high storage capacities and excellent long-term stability have attracted considerable attention. In this study, we investigate the mechanistic role of sulfur modification on platinum θ-alumina catalysts in enhancing the dehydrogenation of perhydro-benzyltoluene (H₁₂-BT), a representative liquid organic hydrogen carrier (LOHC). Although sulfur-modified Pt/Al₂O₃ catalysts exhibit improved reaction rates and durability, the fundamental mechanisms governing catalyst–intermediate interactions remain insufficiently understood. To elucidate these effects, we adopted a surrogate-based approach employing simpler monocyclic analogues (methylcyclohexane, dimethylcyclohexane, toluene, and xylene) to mimic the behavior of complex bicyclic intermediates. In-situ DRIFTS analysis at 320 °C revealed that sulfur promotes favorable re-adsorption through aliphatic functionalities rather than aromatic rings, thereby facilitating complete dehydrogenation and suppressing the formation of carbonaceous residues. In contrast, unmodified catalysts preferentially re-adsorb aromatic intermediates, leading to site blockage and carbon deposition. These findings highlight the pivotal influence of catalyst–intermediate interactions on the reaction dynamics and provide valuable guidance for designing more efficient LOHC dehydrogenation catalysts.
1) ACS Catalysis 2025, 15, 7, 5531-5545