Search NASA⌕ Search

SEARCH · Search NASA

Results for “hydrogen carriers”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Integrated Systems-to-Atoms (S2A) Framework for Designing Resilient and Efficient Hydrogen Infrastructure Solutions

The success of a future clean hydrogen infrastructure will depend on technology performance, operating conditions, and system configuration, which will be integrated to meet specific end-use requirements. We introduce a Systems-to-Atoms framework to cosimulate material, device, and system design for clean hydrogen storage and transport. Here we present a demonstration scenario in which hydrogen is distributed using a liquid organic hydrogen carrier to 700 bar refueling stations. Cross-scale analysis on hydrogen release at the refueling station reveals that while a high reaction pressure (up to 100 bar) may not enhance the catalyst performance, it can lead to system-level cost savings (up to 5% of total refueling station cost) due to savings in downstream gas compression. Further, a typically low-performing dehydrogenation catalyst material (e.g., copper) may be preferred over a high-performing catalyst (e.g., palladium) at different operating conditions when considering overall system affordability and supply chain resilience.

08 HYDROGEN↗
DOE OSTI2026

Modulating Operational Conditions to Mitigate Deactivation in Formate Dehydrogenation on Pd Phases

In heterogeneous catalysis, poisoning by surface-bound intermediates poses a major barrier to sustained catalyst performance in (de)hydrogenation reactions. Formate/bicarbonate systems, as liquid organic hydrogen carriers (LOHCs), offer a CO 2 -integrated, low-temperature pathway for hydrogen storage and release, making them attractive for circular energy applications. However, their lower hydrogen density and susceptibility to catalyst deactivation limit their competitiveness compared to conventional LOHCs like methylcyclohexane. Here, this study investigates the mechanistic origins of formate (HCOO – ) dehydrogenation and associated deactivation on Pd interfaces. Using density functional theory (DFT) simulations, we show that under thermocatalytic conditions, strongly bound formate accumulates on the catalyst surface (Pd(111)), blocking active sites, raising activation barriers, and leading to progressive performance loss. Because formate adsorption involves charge transfer, we exploit its sensitivity to electronic structure by modulating the electrochemical potential of the catalyst. Our results reveal that hydrogen transfer from water and formate exhibits opposing potential dependencies, providing insights into the opposing driving forces behind both catalytic activity and poisoning. To further probe this phenomenon, we examine electrochemically induced phase transitions in Pd, focusing on PdO(100) and PdH(110), which are stable under oxidizing and reducing potentials, respectively, and demonstrate enhanced dehydrogenation activity between −0.4 and 0.2 V vs standard hydrogen electrode (SHE). Complementary thermal treatments help decouple kinetic and thermodynamic contributions to intermediate binding. These findings underscore the critical role of the catalyst phase and external stimuli in dictating poison-active site interactions and highlight phase engineering as a promising strategy to mitigate deactivation. This work offers mechanistic insights and design principles for developing more resilient and efficient catalysts for LOHC applications under realistic operating conditions.

Pd phase↗
DOE OSTI2020

Catalytic Hydrogen Production from Methane: A Review on Recent Progress and Prospect

Natural gas (Methane) is currently the primary source of catalytic hydrogen production, accounting for three quarters of the annual global dedicated hydrogen production (about 70 M tons). Steam–methane reforming (SMR) is the currently used industrial process for hydrogen production. However, the SMR process suffers with insufficient catalytic activity, low long-term stability, and excessive energy input, mostly due to the handling of large amount of CO 2 coproduced. With the demand for anticipated hydrogen production to reach 122.5 M tons in 2024, novel and upgraded catalytic processes are desired for more effective utilization of precious natural resources. In this review, we summarized the major descriptors of catalyst and reaction engineering of the SMR process and compared the SMR process with its derivative technologies, such as dry reforming with CO 2 (DRM), partial oxidation with O 2 , autothermal reforming with H 2 O and O 2 . Finally, we discussed the new progresses of methane conversion: direct decomposition to hydrogen and solid carbon and selective oxidation in mild conditions to hydrogen containing liquid organics (i.e., methanol, formic acid, and acetic acid), which serve as alternative hydrogen carriers. We hope this review will help to achieve a whole picture of catalytic hydrogen production from methane.

08 HYDROGEN↗
DOE OSTI2025

A Full-Cell Model for Direct Toluene Electro-Hydrogenation Electrolysis

Liquid organic hydrogen carriers (LOHCs) are organic molecules that undergo a hydrogenation/dehydrogenation cycle to enable storage and transportation of hydrogen fuel under ambient conditions. One promising LOHC candidate is toluene, which can be converted to methylcyclohexane (MCH) electrochemically, enabling a decarbonized process when green electricity is used. In this study, we developed a full-cell model for the direct electro-hydrogenation of toluene to MCH, utilizing a zero-gap membrane electrode assembly architecture. The model incorporates electrochemical kinetics, ionic transport, water transport across the membrane, and mass transport effects. Electrochemical kinetics are characterized using Tafel analysis on Pt/Ru catalyst. The model is validated against experimental data, including polarization curves, Faradaic efficiencies, and water crossover. A voltage breakdown analysis shows that the performance is dominated by kinetic losses, and the model is used to carry out a comparison of different toluene electro-hydrogenation reaction catalysts. Finally, a sensitivity analysis is conducted on key design parameters illustrating which can be modified to maximize electrolyzer performance. The cathode specific surface area and cathode porous transport layer thickness (PTL) have the largest impact on the current density, while the PTL thickness and Pt loading in the PTL have the largest impact on Faradaic efficiency.

Ehlinger, Victoria M. [Lawrence Livermore National↗
DOE OSTI2024

Intensification and Integration of Hydrogen and Ammonia Production

In this project the Colorado School of Mines developed a more efficient method for on-site and on-demand generation of high purity hydrogen from ammonia for hydrogen fueling stations. Used primarily as a fertilizer, ammonia is the world’s highest volume commodity chemical. Having 17.6% hydrogen by mass, it also shows potential as a hydrogen carrier and carbon-free fuel. The team developed new technology to generate fuel cell quality hydrogen from ammonia using a catalytic membrane reactor (CMR). In addition, during the project we pivoted to use this CMR technology for the production of NH3/H2 mixtures for use in clean combustion applications. We demonstrated that these mixtures may serve as a drop-in replacement for conventional hydrocarbons such as natural gas. This project entails development of new catalysts, new membranes, and their innovative integration. This project helped generate >$4M in follow on funding at Mines, and resulted in the formation of a clean tech startup, Blaze Energy Technologies, which has licensed IP developed in this project and is working to commercialize this technology.

08 HYDROGEN↗
DOE OSTI2025

Combined TDLAS and chemiluminescence imaging in a flat flame burner operated with NH3/H2 blends

Ammonia is viewed as a viable hydrogen carrier due to favorable storage and transport characteristics. While it can be re-converted to hydrogen at point-of-use via thermal catalytic cracking, direct utilization in combustion systems can result in reduced costs and improved efficiency. A major barrier to this approach is the low flammability and potential for high nitrogen oxide emissions, driven by fuel-bound nitrogen and complex kinetic pathways. While a number of kinetic mechanisms currently exist for simulating ammonia combustion, a major need continues to be direct information about species profiles in easy-to-model systems capable of isolating chemical kinetics from multi-dimensional fluid dynamic effects. This paper reports on recent species measurements made in a flat flame burner using a combined tunable-diode-laser-absorption-spectroscopy (TDLAS) and chemiluminescence imaging approach. Three flame conditions were included representative of NH3/H2 blends, partially cracked NH3 (inc. N2), and 100% NH3 with enhanced air (30% oxygen). Two NIR distributed feedback (DFB) laser diodes were used to determine H2O concentration and temperature (via ratio thermometry) at various radial and axial positions, after which an inverse Abel transform was used to infer centerline values. Companion images were collected using a Princeton Instrument PI-MAX intensified camera equipped with a 105mm UV lens and multiple filter sets targeting OH*, NH*, and NH2* emission. Results were compared to companion Cantera burner-stabilized flame simulations using various kinetic mechanisms. A recent mechanism including excited species chemistry was also included, to investigate whether excited and ground state profiles exhibit significant differences.

ammonia combustion↗
DOE OSTI2021

Stabilized open metal sites in bimetallic metal–organic framework catalysts for hydrogen production from alcohols

Liquid organic hydrogen carriers such as alcohols and polyols are a high-capacity means of transporting and reversibly storing hydrogen that demands effective catalysts to drive the (de)hydrogenation reactions under mild conditions. We employed a combined theory/experiment approach to develop MOF-74 catalysts for alcohol dehydrogenation and examine the performance of the open metal sites (OMS), which have properties analogous to the active sites in high-performance single-site catalysts and homogeneous catalysts. Methanol dehydrogenation was used as a model reaction system for assessing the performance of five monometallic M-MOF-74 variants (M = Co, Cu, Mg, Mn, Ni). Co-MOF-74 and Ni-MOF-74 give the highest H 2 productivity. However, Ni-MOF-74 is unstable under reaction conditions and forms metallic nickel particles. To improve catalyst activity and stability, bimetallic (NixMg 1-x )-MOF-74 catalysts were developed that stabilize the Ni OMS and promote the dehydrogenation reaction. An optimal composition exists at (Ni 0.32 Mg 0.68 )-MOF-74 that gives the greatest H2 productivity, up to 203 mL gcat -1 min -1 at 300 °C, and maintains 100% selectivity to CO and H 2 between 225–275 °C. The optimized catalyst is also active for the dehydrogenation of other alcohols. DFT calculations reveal that synergistic interactions between the open metal site and the organic linker lead to lower reaction barriers in the MOF catalysts compared to the open metal site alone. This work expands the suite of hydrogen-related reactions catalyzed by MOF-74 which includes recent work on hydroformulation and our earlier reports of aryl-ether hydrogenolysis. Moreover, it highlights the use of bimetallic frameworks as an effective strategy for stabilizing a high density of catalytically active open metal sites.

08 HYDROGEN↗
DOE OSTI2024

Understanding Direct-Ammonia Protonic Ceramic Fuel Cells: High-Performance in the Absence of Precious Metal Catalysts

Ammonia has received considerable attention as a promising carbon-free hydrogen carrier. At temperatures above 400 °C, NH 3 is thermodynamically unstable with respect to decomposition into nitrogen and hydrogen and is, thus, suitable for direct use in solid oxide fuel cells (SOFCs) without external reforming. However, poor catalytic activity for ammonia decomposition at the moderate temperatures of protonic ceramic fuel cell (PCFC) operation has resulted in low fuel cell power output relative to operation on hydrogen and likely contributes to reported cell degradation. Here we prepared cells based on a thermodynamically robust electrolyte, a high activity cathode, and an anode with a distinctive structure to overcome challenges of poor activity and stability. Furthermore, the cells delivered peak power densities of 0.59 and 0.44 W cm –2 under H 2 and NH 3 , respectively, at 500 °C, excellent stability over a period of 200 h, and no detectable NO x in the anode exhaust gas.

25 ENERGY STORAGE↗
DOE OSTI2025

Mapping ammonia-diesel combustion on a single-cylinder 107 mm bore diesel engine retrofitted for ammonia port-fuel injection

Ammonia is garnering significant interest from the international maritime sector as an alternative fuel. It is attractive as a hydrogen carrier and as a fuel because it has a higher volumetric energy density compared with gaseous or liquid hydrogen, making it easier to store and transport without requiring high pressures or cryogenic storage. Ammonia has significant toxicity concerns, but safe handling procedures have already been established because it is one of the most widely produced chemicals worldwide for use as a fertilizer. Barriers to consuming NH 3 as a fuel in engines include (1) less favorable ignition energy and flame speed compared with conventional fuels; (2) emissions challenges, including potentially high NH 3 , NO X , and N 2 O emissions; and (3) fuel delivery and handling challenges. Although NH 3 has been used to fuel compression-ignition marine engines in limited demonstration projects, technical barriers still exist. The use of NH 3 as a fuel in smaller-bore, high-speed auxiliary engines for large vessels and for smaller inland and coastal marine applications remains unaddressed. This work investigates a late-injection diesel pilot ignition dual-fuel NH 3 strategy using a single-cylinder, high-speed Cummins four-stroke diesel engine platform with a 107 mm bore and 1.1 L displacement per cylinder. The engine was modified for port fuel injection of heated gaseous anhydrous NH 3 . The diesel fuel injection system and the combustion geometry were unmodified to represent a retrofit application, which would minimize additional hardware to maximize diesel fuel displacement with NH 3 . Furthermore, the results show the applicability of a late injection diesel pilot strategy to overcome the challenging fuel properties of NH 3 over the engine operating envelope. Mapping results focusing on emissions are presented, and comparisons are made to a conventional diesel combustion baseline.

Ship engines↗
DOE OSTI2026

Discovery of hydrogen storage molecules using large language models and machine learning

Accelerating the discovery of new molecules with targeted properties is a central challenge in molecular design. In this contribution, we present an AI-driven molecular discovery framework that integrates Large Language Models (LLMs) for generative molecular design with Machine Learning (ML)-based screening to identify novel Liquid Organic Hydrogen Carrier (LOHC) candidates. Using the developed framework, LOHC molecules were systematically generated, evaluated, and refined iteratively, combining LLM-guided molecular generation and ML-predicted hydrogenation enthalpies (Δ H ), under physicochemical property constraints such as optimal melting points (MP), desired hydrogen storage capacity (wt% H 2 ), and synthetic accessibility (SA) scores. This approach enabled the discovery of 42 new LOHC candidates in two distinct campaigns, one seeded with experimentally known and another with previously computationally identified LOHCs, respectively. Although we began with different numbers of starting molecules (31 vs . 7 seed molecules), both runs yielded a comparable number of viable candidates, suggesting an influence of chemically intuitive seed molecule selection for success. Selected LOHC molecules, such as 3-methyl pyridine, 1-ethylnapthalene, 1,1-diphenylethane, and benzofuran, were experimentally tested and compared with benchmark LOHCs (toluene and 9-ethylcarbazole) for hydrogenation using a series of commercial supported metal catalysts. The order of conversion into fully hydrogenated products at 200 °C was 3-methyl pyridine (100%) > 9-ethyl carbazole (86.4%) > 2,3-benzofuran (74%) > 1,1-diphenylethane (66.9%) > 1-ethylnapthalene (66.7%) > toluene (57%), further validating the AI-guided molecular design. This study demonstrates promise of LLM-driven molecular design in conjunction with ML-based screening for accelerated discovery and design of molecules.

Harb, Hassan [Argonne National Laboratory (ANL), A↗
DOE OSTI2021

H2@Scale 2.0: Realizing the Benefits of a Hydrogen-Based Energy System

Throughout the world, hydrogen is increasingly recognized as the critical, central component for a clean, sustainable, efficient, and economic energy system. Hydrogen is remarkable for its ability to carry, store, and interconvert energy - its chemical energy can be used for clean and efficient chemical conversions to products and fuels; electricity generation; and heat generation. Hydrogen can be used as a storage medium, even for seasonal storage, to enable larger-scale deployment and use of renewable electricity. As an energy carrier, hydrogen is central to cross-sector coupling and clean, efficient transportation fuels and industrial processes, enabling decarbonization of products and services while meeting customer expectations.

chemical conversions↗
DOE OSTI2023

Hydrogen Considerations Tree: Executive Deck [Slides]

The Hydrogen Considerations Tree is designed to enhance the understanding and capabilities of U.S. Agency for International Development Missions and country partners, empowering them to make informed decisions regarding potential support for hydrogen and its derivatives, such as e-fuels, hydrogen carriers, or ammonia, within their respective nations. Moreover, the Considerations Tree is designed to provide fundamental and applied information for the identification of deployment, regulation, policy priorities for hydrogen technologies in the context of each country or region. Key topics are organized into a "considerations tree," enabling stakeholders to systematically and holistically address technical, regulatory, economic, environmental, social, and analytical questions.

08 HYDROGEN↗
DOE OSTI2025

Overcoming Barriers in Electrochemical Toluene Hydrogenation for Efficient Hydrogen Storage by Pt 3 Au Alloy Catalysts

Hydrogen storage and transportation are essential for the hydrogen economy, and liquid organic hydrogen carriers (LOHCs), such as a toluene/methylcyclohexane (TOL/MCH) system, offer significant advantages in terms of safety and efficiency. However, the electrochemical reduction of TOL to MCH (TER) faces challenges from competing with the hydrogen evolution reaction (HER) and catalyst instability. Here, in this study, Pt 3 Au is introduced as a highly effective catalyst for TER. Through density functional theory screening, we identified distinctive properties of Pt 3 Au, including enhanced binding to the TER intermediates and effective HER suppression. Experimental validation confirmed these computational predictions, with Pt 3 Au achieving the highest reported Faradaic efficiency (98%) in proton exchange membrane systems. Moreover, long-term testing demonstrated that Pt 3 Au maintained Faradaic efficiencies of >90% over 9 h, highlighting its robustness and operational stability. By integrating computational modeling and experimental evaluation, this work addresses key limitations in LOHC catalysis. Pt 3 Au establishes a benchmark for selective and stable TER performance, paving the way for advanced hydrogen storage technologies. These findings emphasize the critical role of rational catalyst design in overcoming the challenges associated with scalable and efficient hydrogen storage solutions.

LOHC↗
DOE OSTI2022

Large-scale Hydrogen Storage – Risk Assessment Seattle City Light and Port of Seattle [Abstract]

This CRADA presents the strategy that Pacific Northwest National Laboratory (PNNL) and Sandia National Laboratories (SNL) will take to support Seattle City Light (SCL), and the Port of Seattle (Port) in performing a risk assessment of large-scale hydrogen storage. Risk assessment is often used to ensure that adequate measures are taken to protect workers and the public, the environment, infrastructure, and assets. A detailed risk assessment can also be used to direct funding and upgrades, to specific components and sub-systems in order to mitigate risks to the larger system. In this way risk assessments are often employed as a part of a larger risk management strategy, with the goal of minimizing the occurrence of hazards and to identify means to limit their consequences. Risk assessment is often used to engage and inform regulators, and to communicate how specific regulations are being met. However, it is important to note that the proposed work is not intended for SCL and the Port to use in order to gain regulatory acceptance for their proposed activities. The work performed as a part of this effort will be a preliminary risk assessment for early-stage component and system designs and should be considered research and development (R&D). As such, the proposed work will be performed to a quality level and design maturity consistent with R&D and is not considered appropriate for final safety analysis and regulatory compliance purposes. Previous and on-going work at SCL and the Port demonstrated the utility of deploying hydrogen systems at the Port. The deployment of hydrogen at the Port is a part of a larger vision of using hydrogen to address a range of issues for SCL and the Port. These include large-scale fueling of MD/HD vehicles, cargo-handling equipment (CHE), and harbor vessels to reduce emissions; support of adjacent LD vehicles; support of critical port operations during extreme events (i.e., resiliency); deferral of more capital- and time-intensive electrical distribution system upgrades while still supporting evolving port operations and decarbonization efforts; facilitating electrification by establishing energy storage as a grid resource, starting at strategic port locations; creation of a flexible market resource that can be used by SCL to generate revenue via arbitrage; support of planned future maritime operations that involve heavy use of hydrogen for ocean-going vessels; and future end-use applications involving natural gas pipeline hydrogen injection. Ultimately, the success of these activities is underpinned by the deployed storage capacity. Large-scale deployment of hydrogen systems will require hydrogen storage at a scale that has not been demonstrated. In addition, the ideal location for such multi-use systems is near the end user which will often necessitate deploying into urban and/or industrial areas. A detailed risk assessment using the Port as a test case is necessary to ensure the deployment of large-scale hydrogen is successful. Many technologies have been proposed for hydrogen storage; however, these technologies need to be analyzed as they apply to an actual site. The physical infrastructure and hydrogen use cases for the Port will be analyzed, and a risk assessment for compressed hydrogen, liquified hydrogen, and Liquid Organic Hydrogen Carrier (LOHC) storage will be performed. These risk assessments will be useful for understanding how each of these technologies would perform in terms of facility and public safety. The operating states of the proposed hydrogen systems at the Port will be analyzed and incorporated into the storage risk assessment. Scalability will also be analyzed to understand how future port uses would affect the overall risk assessment. Finally, using the risk assessment as a tool to inform engagement and to gain stakeholder acceptance will be explored.

08 HYDROGEN↗
DOE OSTI2023

Activated magnesium boride materials for hydrogen storage

Some embodiments described herein provide for methods for synthesizing magnesium borohydride from hydrogenation of magnesium boride at moderate temperature and pressure in the presence of a modifier. The modifier may be in form of hydrides, liquid hydrogen carriers, ammonia borane, metallic species, croconate anion based materials, ethers, amines or imines, metal carbides, borides, graphene, arenes, magnesium, aluminum, calcium or ionic liquids. Some embodiments provide for charging magnesium boride in presence of a modifier at high pressure hydrogen while simultaneously heating the material. The modification in some instances may lead to an improved magnesium boride product with enhanced properties for application in other hydrogen storage systems.

Severa, Godwin↗
DOE OSTI2026

Systems-To-Atoms (S2A): enabling hydrogen for climate security

The project addresses a critical gap in hydrogen infrastructure by integrating system-level energy models with atomic-scale material simulations in a unified Systems-to-Atoms (S2A) framework. The motivation stems from the need to develop efficient, cost-effective, and durable hydrogen transport and utilization technologies to support decarbonization of hard-to-electrify sectors such as heavy-duty transportation. Current system models lack awareness of material performance mechanisms, while material-scale models do not account for system-level usage and variability. To bridge this divide, the team developed a co-simulation capability linking techno-economic analyses, reactor/process-flow modeling, and molecular-scale catalysis simulations. Applied to hydrogen delivery in California, the framework enabled comparative evaluations of compressed, cryogenic, and liquid organic hydrogen carrier (LOHC) pathways, highlighting how catalyst operation and unit process efficiency influence overall performance. The results demonstrate that no single material or transport mode is universally optimal; instead, heterogeneous solutions tuned to specific operational contexts deliver better performance. The project delivers a new capability for cross-scale material co-design, advancing hydrogen infrastructure readiness and informing DOE and LLNL missions in climate and energy resilience.

organic↗
DOE OSTI2025

Combined TDLAS and chemiluminescence imaging in a flat flame burner operated with NH3/H2 blends

Ammonia is a promising hydrogen carrier due to its favorable storage and transport characteristics. However, its direct use in combustion systems is limited by low flammability and potential for high nitrogen oxide emissions. To better understand ammonia combustion, researchers conducted experiments using a flat flame burner and measured species profiles using tunable-diode-laser-absorption-spectroscopy and chemiluminescence imaging. They tested three flame conditions with different ammonia-hydrogen blends and oxygen levels. The results were compared to simulations using various kinetic mechanisms, including one that accounts for excited species chemistry. The goal is to provide direct information about species profiles in a simple system, isolating chemical kinetics from fluid dynamic effects, which can inform the development of more efficient and low-emission combustion systems using ammonia.

ammonia combustion↗