The work comes from SUPREN, a research group at EHU that is leading a large-scale European project known as UnLOHCked, focused on the social, environmental and economic assessment of large-scale green hydrogen supply chains in Europe. Victoria Laura Barrio, full professor at EHU and lead researcher of the project, explains that one of the central challenges facing these supply chains is deceptively simple: how to move and store the gas itself. Hydrogen contains a vast amount of energy per kilogram, but as an ultra-light gas it occupies an enormous volume, which makes transporting and storing it both technically awkward and expensive. Solving that logistics problem is widely seen as a prerequisite for building an international hydrogen market.

One of the most promising answers is a family of materials known as liquid organic hydrogen carriers, or LOHCs. These are organic liquids that behave much like conventional oils, into which hydrogen is incorporated through a straightforward chemical reaction. Because the hydrogen is chemically bound within a pumpable liquid, it can be stored and transported using existing oil and gas infrastructure, a fact that could dramatically lower the barriers to international trade. At the destination, the hydrogen is released from the carrier through a reverse process, and the carrier liquid can be returned for reuse. The researchers emphasise the technology’s considerable potential and foresee it playing a key role in the global green hydrogen trade in the near future.

The strategic logic of LOHC-based trade is already shaping national planning. Several countries are developing future strategies for the production, export, import and consumption of hydrogen, and Barrio notes that it would make particular sense to bind hydrogen to the liquid carrier in southern Europe or Africa, where solar energy is highly competitive, or in regions with strong wind energy potential. The hydrogen could then be shipped easily in the form of LOHC, riding on infrastructure originally built for fossil fuels. In this vision, sun-belt and wind-belt exporters become the energy suppliers of a decarbonising world, while industrial importers in northern Europe and East Asia plug into those flows.

To test whether such flows can truly be sustainable, EHU researcher Irene Rey carried out a detailed sustainability assessment of these international supply chains, now published in the Chemical Engineering Journal. The team performed a life cycle assessment of every stage involved in generating green hydrogen, hydrogenating it into the carrier liquid, transporting it by sea to the end consumer, releasing it at its destination and returning the carrier liquid, while excluding the final use and consumption of the hydrogen itself. The analysis contemplated different configurations of producing countries with high renewable potential, including Namibia, Saudi Arabia, Norway and Spain, and consumer countries such as Germany, the Netherlands, Japan and Italy, alongside maritime transport routes and different types of land-based distribution.

The study’s principal innovation lies in what it added to the conventional toolkit. Life cycle assessment and techno-economic analysis are standard instruments for evaluating energy systems, but the researchers also incorporated a social risk analysis of the supply chains, an aspect that has been little studied until now. Because hydrogen production would be located in countries with markedly different social, economic, political and institutional conditions, the production stage shows a high variation in potential social risks. Labour standards, governance quality, human rights conditions and community impacts all vary enormously between candidate exporter nations, meaning that two hydrogen molecules with identical carbon footprints can carry very different social burdens depending on where and how they were made.

The technical results point clearly to where improvement efforts should be concentrated. The researchers found that further work is needed to improve the efficiency of green hydrogen production and of the release of hydrogen from the carrier, since both stages involve high energy consumption and are the most critical links in the supply chain. Electrolysis powered by renewable electricity and the dehydrogenation step at the point of import together determine much of the overall energy penalty, emissions profile and cost of delivered hydrogen. Gains in these two stages would ripple through the entire system, improving every sustainability dimension simultaneously.

Yet the study’s most sobering conclusion is that no configuration emerges as a winner on all fronts. According to Rey, the results show that there is no perfect scenario delivering benefits across the social, environmental and economic dimensions at once. Instead, she argues, a balance should be achieved across the entire supply chain, with priority not given only to economic aspects. Routes that minimise delivered cost may concentrate social risk in vulnerable producer regions, while configurations that maximise environmental performance may struggle to compete commercially. Designing the future trade will therefore require explicit trade-off analysis and policy frameworks that internalise social and environmental performance alongside price.

The stakes of getting this right are considerable. Hydrogen could account for up to 14 percent of global final energy consumption by 2050, with an ever-increasing share traded internationally as new value chains emerge, a shift likely to reconfigure global energy trade much as oil did in the twentieth century. Regions with abundant renewable resources, such as Africa, Latin America, the Middle East and Oceania, are increasingly viewed as potential exporters, while Europe, Japan and South Korea are expected to become key importers. Rey cautions that designers of green hydrogen corridors must do more than simply reduce carbon emissions and production costs; they must also consider the geopolitical and social implications of the flows they create.

Her question cuts to the heart of the energy transition’s equity dilemma: how can a future hydrogen trade be developed without reproducing the resource extraction dynamics in which the Global South supplies raw energy for the benefit of the technological and economic development of the Global North? The EHU study, conducted as part of Rey’s doctoral thesis at the Chemical and Environmental Engineering Department of the Bilbao School of Engineering under the direction of Ion Agirre and Professor Barrio, and carried out in collaboration with the Polytechnic University of Milan, offers a springboard for answering it. By demonstrating that social risk can be quantified and integrated into supply chain design alongside environmental and economic metrics, it provides policymakers and industry with a practical framework for building a hydrogen trade that is not only clean and competitive, but also just.

Subject of Research: Sustainability assessment of international LOHC-based green hydrogen supply chains

Article Title: The design of the future global trade in green hydrogen should also consider social and environmental aspects

Article References: The design of the future global trade in green hydrogen should also consider social and environmental aspects. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: green hydrogen, liquid organic hydrogen carriers, LOHC, hydrogen supply chains, life cycle assessment, social risk analysis, energy transition, renewable energy, global hydrogen trade, sustainability, electrolysis, energy policy

The essence of their research lies in harmonizing hydrogen’s production with the Earth’s ecological limits. While hydrogen itself emits no greenhouse gases on use, the processes involved in producing it can have profound environmental impacts if not carefully managed. Currently, hydrogen production is predominantly reliant on fossil fuels through methods such as steam methane reforming, which undermines the climate benefits of hydrogen by releasing significant CO2 emissions. The team’s analysis critically evaluates alternative pathways, emphasizing electrolysis powered by renewable energies as a cornerstone for sustainable hydrogen generation.

Electrolysis, the splitting of water into hydrogen and oxygen, presents an elegant solution but depends heavily on the availability of clean electricity sources. The researchers delve into the feasibility of scaling renewable energy infrastructures to meet the soaring electricity demands implied by a hydrogen economy. They underscore the importance of integrating solar, wind, and hydropower to create a diversified energy portfolio that can sustainably support hydrogen production without exacerbating land use or biodiversity loss.

Moreover, the study highlights the nuanced relationship between hydrogen production and water usage. Electrolysis, while clean in emissions, requires substantial volumes of high-purity water, a resource already under pressure in many regions. The authors propose innovative water management strategies, such as using seawater desalination powered by renewables and recycling process water, to mitigate freshwater stress. They further stress the significance of geographic specificity when evaluating hydrogen pathways, as resource availability and environmental constraints vary drastically across regions.

A critical innovation in this research is the application of planetary boundaries—conceptual thresholds for key Earth system processes—providing a quantifiable framework to assess environmental impacts and ensure sustainability. The team models various hydrogen production scenarios, analyzing their implications on climate change, freshwater use, nitrogen and phosphorus cycles, and land system changes, among others. This holistic approach reveals that meeting global hydrogen demand within planetary boundaries requires meticulous balancing of technological choices, resource management, and policy interventions.

Crucially, their findings identify blue hydrogen—produced from natural gas combined with carbon capture and storage—as a potential transitional option. While not entirely free from emissions, blue hydrogen could bridge the gap toward green hydrogen dominance, provided that carbon capture technologies advance and scale efficiently. This transitional role, however, must be strictly limited to avoid locking in fossil fuel dependencies and undermining long-term sustainability goals.

In their exploration of supply chains, the researchers emphasize the need for infrastructure development that minimizes environmental burdens. The impacts of building electrolyzers, transport networks, and storage facilities must be anticipated and mitigated, employing circular economy principles to reduce material waste and energy consumption. This highlights the importance of lifecycle assessments in guiding hydrogen deployment strategies to prevent shifting burdens from one environmental domain to another.

The study also evaluates the socioeconomic dimensions intertwined with hydrogen pathways. Access to clean energy, job creation, and equity issues play vital roles in shaping the acceptance and success of hydrogen technologies. The researchers advocate for inclusive policies that ensure technological benefits are widely distributed, especially in vulnerable communities disproportionately affected by environmental degradation and energy poverty.

A forward-looking perspective is embedded in their vision, recognizing the uncertainty and rapid evolution of energy technologies. The authors call for adaptive management frameworks and continuous monitoring to align hydrogen development with emerging scientific insights and environmental feedback. This adaptable approach is essential to navigate the inherent complexities and dynamic nature of global energy transitions.

In summary, this seminal work by Lejeune, Kara, Hauschild, and collaborators offers an indispensable blueprint for steering global hydrogen production into a sustainable future navigable within our planetary limits. Their integrated methodology, combining environmental science, engineering, and policy analysis, advances the discourse beyond simplistic solutions towards a nuanced and responsible energy transformation. Success in this endeavor promises not only climate stabilization but also the preservation of the Earth’s life-supporting systems for generations to come.

The implications of this research ripple across multiple sectors, urging governments, industries, and academia to unite in orchestrating a hydrogen economy that uplifts humanity without depleting the planet. It challenges innovators to rethink resource efficiency, encourages policymakers to embed ecological thresholds in regulatory frameworks, and invites society at large to embrace a paradigm shift where sustainability is non-negotiable.

As the urgency of climate action intensifies, this comprehensive pathway delineated by the authors represents a pivotal juncture—a clarion call to harness hydrogen’s promise responsibly. It is a testament to the transformative power of interdisciplinary research in paving the way towards a resilient, low-carbon world that thrives within the safe operating space defined by planetary boundaries.

Subject of Research: Sustainable global hydrogen production pathways within planetary boundaries

Article Title: Pathways to global hydrogen production within planetary boundaries

Article References:
Lejeune, M., Kara, S., Hauschild, M.Z. et al. Pathways to global hydrogen production within planetary boundaries. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70168-x

Image Credits: AI Generated

In response to these challenges, the EU-funded project SUPREME represents a vital leap forward. Coordinated by the University of Southern Denmark with key participation from Graz University of Technology (TU Graz), this international collaboration aims to innovate a next-generation electrolysis technology free from PFAS. The SUPREME initiative is distinguished not only by its commitment to eliminating harmful substances but also by its goal to drastically reduce the dependency on critical and expensive raw materials such as iridium. By achieving these improvements, the project strives to create a PEM electrolysis process that is both cost-effective and environmentally sustainable, thereby accelerating the green hydrogen economy.

A crucial aspect of SUPREME’s research involves assessing alternative, commercially available PFAS-free materials for membrane synthesis and other electrolysis components. Merit Bodner and her team at TU Graz are focused on extensive material evaluation. This includes rigorous testing to ensure that these safer and more sustainable materials can match the durability and operational efficiency of current industry standards when deployed in continuous industrial settings. This line of inquiry addresses a fundamental obstacle: the need for materials that not only minimize environmental impact but also maintain the stringent performance requirements of commercial hydrogen production.

Complementing this effort, TÜBITAK—the Scientific and Technological Research Council of Turkey—is spearheading the development of new PFAS-free microporous membranes designed for improved sustainability. These advanced membranes are intended to enhance the electrochemical processes within PEM electrolyzers, thereby offering a pathway to both higher efficiency and ecological compatibility. The coordinated research across these institutions reflects a strategic, multifaceted approach to remaking PEM electrolysis from the ground up.

Another critical dimension of the SUPREME project is the reduction and recycling of iridium, a platinum-group metal integral to current PEM electrolysis catalysts but characterized by high cost and limited availability. Researchers at the University of Southern Denmark, in collaboration with the British catalyst firm Ceimig, are pioneering ways to slash iridium usage by up to 75%, a transformation that could immensely reduce the capital expenditure of electrolyzer systems. Beyond mere reduction, they aim to establish sophisticated recycling processes that can reclaim approximately 90% of iridium in use, thus addressing raw material scarcity and improving the sustainability profile of green hydrogen production technologies.

The German Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) contributes to SUPREME by manufacturing the membrane electrode assemblies (MEAs), which integrate catalysts with membranes to facilitate efficient electrochemical reactions. Their expert fabrication capabilities ensure that the newly developed components meet industrial quality requirements, bridging laboratory innovations with scalable production methods. Meanwhile, Norway’s Element One Energy AS is innovating in system design by developing a novel rotating electrolyser, which promises to enhance hydrogen production efficiency through improved mass transport and catalyst utilization dynamics.

SUPREME’s impact extends beyond technological advancements, as it embodies a model of European scientific collaboration backed by the Clean Energy Transition Partnership (CETPartnership) and co-funded by the European Commission. This multidisciplinary and cross-national approach not only harnesses diverse expertise but also aligns with Europe’s broader strategy for energy transition and climate resilience. By focusing on sustainability, affordability, and supply chain security, SUPREME sets the stage for green hydrogen to become a truly competitive alternative to fossil-based hydrogen.

The implications of making green hydrogen economically viable and environmentally benign are profound. Hydrogen currently serves as a fundamental feedstock for industrial sectors demanding substantial volumes, including ammonia synthesis, methanol production, and steel manufacturing. Advancements realized through SUPREME could substantially decarbonize these sectors by providing cleaner hydrogen to replace carbon-intensive alternatives. Moreover, cost reductions and material innovations could unlock new applications such as long-term energy storage, making grid stabilization via renewable energy integration more feasible during periods of surplus generation.

A particularly promising outcome of SUPREME would be the democratization of hydrogen technology. Currently, the expense and environmental concerns linked with PEM electrolysis limit accessibility, especially in emerging economies. By developing electrocatalysts and membranes that forgo PFAS and minimize critical metals, the project can help scale up production and reduce barriers for widespread global use. This democratization is crucial for achieving the Paris Agreement goals and ensuring equitable participation in the green energy transition.

While the project’s timeline extends over three years, the anticipated breakthroughs could trigger a paradigm shift in hydrogen production technology. Continuous validation of PFAS-free alternatives for durability and performance under real-world conditions will provide the empirical foundation necessary for industrial uptake. Concurrently, innovations in catalyst technology and component recycling will help secure supply chains prone to geopolitical instability, thus enhancing energy security.

In summary, the SUPREME project embodies a critical, multidimensional effort to overcome some of the most entrenched barriers in green hydrogen technology. By eliminating toxic substances, slashing the usage of rare materials, and fostering efficient recycling methods, it advances a sustainable, cost-competitive hydrogen economy. This research not only holds the promise of transforming industrial hydrogen production but also strengthens the entire renewable energy ecosystem by enabling more flexible, affordable, and sustainable clean energy storage and usage.

Subject of Research: Not applicable
Image Credits: Lunghammer – TU Graz

Keywords

green hydrogen, PEM electrolysis, SUPREME project, proton exchange membrane, PFAS-free materials, iridium reduction, catalyst recycling, renewable energy storage, green energy transition, membrane electrode assemblies, clean energy technology, sustainable hydrogen production

Water electrolysis has gained traction as one of the most promising techniques for green hydrogen production. This process utilizes electrical energy to power an electrolyzer, a reactor that separates water molecules (H2O) into hydrogen (H2) and oxygen (O2). The efficiency of these electrolyzers greatly depends on a specialized membrane designed to prevent the mixing of hydrogen and oxygen gases, which if allowed, could result in explosive reactions. The current industry standard membrane is Nafion, a well-known material that belongs to a category of substances characterized by their persistence in the environment, often referred to as per- and polyfluoroalkyl substances (PFAS).

At Columbia Engineering, a groundbreaking initiative is underway led by chemical engineer Dan Esposito. His team is pioneering a method to replace Nafion membranes with ultra-thin, PFAS-free oxide membranes, potentially reducing the environmental hazards associated with traditional electrolyzers. The research, underpinned by support from the U.S. Department of Energy and in collaboration with industry partners Nel Hydrogen and Forge Nano, seeks to eliminate over 99% of PFAS from electrolyzer systems. This ambitious endeavor highlights a significant leap forward in eco-friendly hydrogen production techniques.

The membrane’s critical role in the electrolyzer’s functionality cannot be overstated. Esposito emphasizes its importance, stating it maintains the critical separation of hydrogen and oxygen gases while allowing protons to pass through. If the membrane fails, not only does the system cease to work, but it can pose significant safety risks. Consequently, Esposito and his research team are dedicated to devising innovative manufacturing techniques that enhance both the efficiency and safety of the proposed oxide membranes.

Notably, the research team has published their findings in the journal ACS Nano, detailing their new approach to creating membranes that are markedly thinner than conventional options. By utilizing silicon dioxide, a less conductive but PFAS-free alternative, the researchers are pushing the boundaries of traditional materials science. The reduced thickness of the membranes, achieved through advanced manufacturing techniques like atomic layer deposition, enhances overall performance, even though silicon dioxide’s baseline conductivity is lower than that of Nafion.

This significant innovation is accentuated by the thickness reduction from approximately 180 microns for Nafion membranes to less than one micron for the new oxide membranes. This is a staggering reduction, with the new membranes being hundreds of times thinner than current standards. Despite the inherent challenges posed by decreased conductivity, the emphasis on membrane thinness is supported by the understanding that resistance relates not merely to material conductivity but also to physical dimensions.

However, a considerably thinner membrane introduces a new set of challenges, particularly concerning structural integrity. Defects such as microscopic cracks or pinholes can compromise membrane performance, leading to hydrogen leakage on the oxygen side — a perilous prospect. Esposito warns that even a few defects per square centimeter can render a membrane entirely unsafe for operational purposes. To address this critical issue, the team has developed an innovative electrochemical approach that specifically targets and seals these defects without risking the membrane’s structural integrity.

Exploiting pulsed voltage applications to instigate selective depositions of nanoscopic plugs within the identified defects showcases the ingenuity of the research team. This method allows for meticulous repair of any holes while preserving low resistance and required thinness, crucial for effective functionality. Esposito’s insight into maintaining pH level stability during the process has proven fundamental, ensuring optimal results without unwanted material deposition on the membrane’s surface.

Laboratory tests have demonstrated thrilling results, with the plugged membranes indicating hydrogen crossover rates up to 100 times lower than that of Nafion, despite their significantly reduced thickness. The substantial implications of these findings could redefine the benchmarks for efficiency and safety in hydrogen production technologies. The team’s commitment to advancing their work indicates a strong trajectory toward commercial applications, transitioning from small-scale tests to prototypes that meet industry demands.

Significantly, while the focus of the research is entrenched in hydrogen production, there are broader applications inherent to this defect-plugging methodology. Potential benefits could arise in various fields, including fuel cells, flow battery development, water treatment processes, and even semiconductor manufacturing. This versatility underscores the multifaceted impact that such innovative research could impart across numerous scientific and engineering disciplines.

Esposito anticipates a future where hydrogen derived from water electrolysis contributes to a larger share of global energy production. Currently, less than 0.1% of hydrogen worldwide is sourced through electrolysis, starkly contrasting with the pressing need for sustainable energy solutions. The endeavor to create high-performance, environmentally responsible membranes is critical as the industry seeks to scale hydrogen production in a sustainable manner.

As the research continues and scales evolve, the significance of Esposito’s findings might reverberate throughout the green technology landscape. The team’s dedication to developing practical solutions for the energy sector exemplifies a hopeful future in which eco-friendly hydrogen production can thrive alongside environmental protection efforts.

This research represents a confluence of innovation, engineering excellence, and environmental stewardship. As such, it lays the groundwork for pioneering strides not only in hydrogen production but also across varied technological fields where such membranes can be effectively utilized. With the world looking for sustainable pathways forward, the implications of this research transcend traditional boundaries, promising a cleaner and more efficient energy future.

Esposito’s vision and the collective efforts of the research team embody the spirit of innovation required to tackle complex global challenges. As they venture into collaboration with industry leaders, the transition from experimental stages to real-world implementation will be closely watched by the scientific community and beyond, with potential ramifications that can reshape our understanding of energy production.

Subject of Research: Replacement of Nafion membranes with PFAS-free oxide membranes for hydrogen electrolyzers
Article Title: Nanoscopic plugs block hydrogen crossover in submicron thick proton-conducting SiO2 membranes for water electrolysis
News Publication Date: October 2023
Web References: https://www.engineering.columbia.edu/academics/departments/chemical-engineering-department
References: DOI: 10.1021/acsnano.5c09555
Image Credits: Esposito Lab

Keywords

Hydrogen production, water electrolysis, Nafion replacement, PFAS-free membranes, silicon dioxide, energy sustainability, electrochemical methods, membrane technology.

Hydrogen production through SMR is a well-established method, primarily used to convert natural gas into hydrogen. However, this process results in significant carbon dioxide emissions, prompting researchers to seek methods that mitigate environmental impact without compromising efficiency. The use of adsorbents in hydrogen separation exemplifies a promising pathway in achieving cleaner hydrogen production.

Metal-organic frameworks are unique materials comprising metal ions interconnected by organic ligands, forming a porous structure with immense surface area. This characteristic renders MOFs particularly suitable for gas adsorption applications, including hydrogen. The versatility of MOFs permits modification of their pore structures, enabling the optimization of their properties for specific applications, which is a significant advantage over traditional adsorbents.

The researchers delve into various types of MOFs, highlighting their distinct qualities and suitability for hydrogen separation in the context of steam methane reforming. Certain MOFs display high selectivity for hydrogen, while others exhibit superior adsorption capacities. Such insights are crucial as they guide the selection of appropriate MOF materials for specific hydrogen separation applications, ultimately contributing to the overall efficiency and sustainability of hydrogen production.

Moreover, the article discusses the influence of temperature and pressure on the adsorption kinetics of hydrogen in MOFs. The interplay between these parameters determines the overall efficiency of the hydrogen separation process. Understanding how these conditions affect MOF performance is essential for optimizing operational protocols in industrial applications, ensuring maximum hydrogen recovery while minimizing energy costs.

The authors also highlight the role of hybrid materials that combine MOFs with other adsorbent technologies. This innovative approach leverages the strengths of multiple materials, potentially yielding enhanced performance in hydrogen separation compared to MOFs or other adsorbents in isolation. Such hybrid systems open new avenues for research and practical applications that could revolutionize hydrogen production practices.

Additionally, the review emphasizes the scalability and economic aspects of utilizing MOFs in hydrogen separation processes. While laboratory-scale experiments showcase promising results, translating these findings into commercially viable processes poses challenges. Factors such as synthesis cost, regeneration potential, and operational stability must be thoroughly evaluated to ensure that MOFs can compete with conventional technologies.

Another significant aspect covered in the research is the environmental implications of employing MOFs for hydrogen separation. As the world shifts towards greener energy solutions, the ability of these frameworks to reduce carbon emissions during hydrogen production aligns seamlessly with global sustainability goals. Implementing MOF technologies could substantially decrease the carbon footprint associated with hydrogen generation from fossil fuels.

In addition to their applications in hydrogen production, the study suggests that MOFs may find utility in other gas separation processes, further broadening their applicability. For instance, the ability to selectively adsorb gases other than hydrogen could lead to advancements in carbon capture and air purification technologies. This versatility makes MOFs a staple of ongoing research in materials science and environmental engineering.

The insights presented by Mudhulu et al. contribute significantly to the existing literature on MOFs and their applications in energy-related fields. Their comprehensive review not only compiles a wealth of knowledge but also sets the stage for future research to explore unexplored avenues in this promising domain. By identifying the key challenges and potential solutions, the authors pave the way for further innovations and advancements in MOF technology.

In summary, the exploration of metal-organic frameworks as adsorbents for hydrogen separation in steam methane reforming represents a critical juncture in the pursuit of cleaner energy solutions. The review by Mudhulu and colleagues underscores the potential of MOFs to revolutionize hydrogen production technologies, with implications that extend beyond hydrogen itself. As researchers continue to refine these materials and their applications, the transition to sustainable energy systems may become more attainable than ever.

In conclusion, the findings articulated in this review emphasize the need for continued investment and research in MOF technologies. As we navigate an era marked by heightened environmental awareness and the pressing necessity to reduce carbon emissions, the advancement of efficient hydrogen production methods becomes increasingly paramount. The integration of MOFs into hydrogen separation processes is a pivotal step towards achieving a sustainable energy future, symbolizing hope for cleaner and more efficient energy production.

Subject of Research: Hydrogen separation using metal-organic frameworks (MOFs) in steam methane reforming.

Article Title: Metal–organic framework (MOF) as adsorbents for hydrogen separation from steam methane reforming: an in-depth review.

Article References:

Mudhulu, S., Kuncharam, B.V.R. & Gupta, S. Metal–organic framework (MOF) as adsorbents for hydrogen separation from steam methane reforming: an in-depth review.
Environ Sci Pollut Res (2025). https://doi.org/10.1007/s11356-025-36963-7

Image Credits: AI Generated

DOI: 10.1007/s11356-025-36963-7

Keywords: Metal-organic frameworks, hydrogen separation, steam methane reforming, carbon emissions, sustainable energy.

Hydrogen’s appeal as a clean energy source is well recognized due to its high energy density and zero carbon dioxide emissions upon combustion. Nonetheless, the widespread adoption of hydrogen fuel has been hindered by the predominant industrial processes that rely heavily on methane steam reforming and other fossil fuel-based techniques. These methods not only produce substantial greenhouse gases but also require significant energy input, undermining the sustainability benefits of hydrogen fuel. The scientific community has long sought alternative pathways to produce hydrogen with a lower carbon footprint, focusing their efforts on catalytic decomposition of ammonia — a hydrogen-rich compound that can serve as a carbon-free hydrogen carrier.

Ammonia’s potential to facilitate a carbon-neutral hydrogen economy is contingent on efficient catalytic processes capable of decomposing it into nitrogen and hydrogen. Traditionally, decomposition reactions demand extremely high temperatures, typically above 700°C, necessitating the use of energy-intensive inputs. Moreover, the catalysts in industrial use heavily involve ruthenium — a scarce and costly transition metal — that further escalates production costs. This fundamental limitation has impeded scalability and economic viability, prompting urgent calls for novel catalysts and reaction environments that can operate under milder conditions using earth-abundant materials.

Addressing these pressing obstacles, Che’s collaborative team pioneered an innovative plasma-assisted catalytic approach to ammonia decomposition. Unlike classical thermal catalysis relying solely on high-temperature energy to drive reactions, plasma catalysis employs energized ionized gases to activate chemical bonds at substantially lower temperatures. This technique not only reduces the thermal energy demand but also enhances reaction kinetics, facilitating efficient nitrogen-hydrogen bond cleavage in ammonia. The strategic use of plasma presents a paradigm shift, enabling viable catalytic activity at temperatures where traditional methods falter, thus offering a path to sustainable hydrogen production with reduced reliance on fossil energy.

The linchpin of this breakthrough lies in the identification of suitable catalysts capable of functioning synergistically with plasma environments. Given the vast landscape of potential bimetallic alloys — exceeding 3,300 combinations — exhaustive experimental screening would be prohibitively time-consuming and resource-intensive. To circumvent this bottleneck, the research team integrated advanced computational simulations with interpretable machine learning algorithms, crafting predictive models that could discern and prioritize catalysts with optimal performance characteristics. This computational-experimental synergy expedited catalyst discovery, allowing the rapid convergence on promising candidates without sacrificing reliability.

Central to the computational framework was a focus on abundant and economically favorable transition metal alloys such as iron-copper and nickel-molybdenum. These candidates were projected by the machine learning models to outperform ruthenium catalysts under plasma-assisted conditions, a claim subsequently corroborated by laboratory validations executed in collaboration with researchers at Dalian University of Technology. The experimental data confirmed that several of these earth-abundant alloys not only matched but in some cases exceeded the catalytic efficiency of precious metal counterparts, establishing a compelling case for their industrial-scale adoption.

An additional dimension to this research was the techno-economic and environmental analysis executed at Northeastern University, which quantified the potential cost savings and emission reductions achievable through plasma catalysis integrated with modular reactor designs. The findings revealed that deploying plasma-assisted ammonia decomposition in compact, scalable reactors could substantially curtail both operational expenses and carbon footprint relative to conventional hydrogen production facilities. This scalability and modularity present opportunities for distributed hydrogen generation, mitigating transportation and storage challenges inherent to hydrogen gas.

Furthermore, the practical implications of this innovative technique extend notably into maritime applications. Ammonia’s high volumetric energy density and relative ease of storage compared to hydrogen gas propose it as an optimal hydrogen carrier in shipping industries. The prospect of onboard conversion of ammonia into hydrogen via plasma-assisted catalysis could power maritime vessels using hydrogen fuel cells, dramatically slashing maritime emissions and advancing global decarbonization targets. This represents a crucial synergy between energy innovation and environmental stewardship in an industry notorious for carbon-intensive operations.

The success of this research underscores the transformative capabilities of combining interpretable machine learning with physics-driven modeling to tackle complex chemical engineering challenges. By illuminating the molecular-level interactions underpinning catalytic performance in plasma environments, the approach transcends traditional black-box AI models, fostering trust and mechanistic understanding vital for practical deployment. The MAC (Modeling and AI in Catalysis) Lab at Worcester Polytechnic Institute exemplifies this integrative vision, driving forward the frontiers of green hydrogen production.

As hydrogen economies evolve globally, breakthroughs like those led by Fanglin Che will be instrumental in overcoming longstanding material and energetic barriers. The convergence of AI, plasma physics, and catalysis not only accelerates the discovery of viable catalysts but also charts a pathway to scalable, economically feasible, and environmentally benign hydrogen fuel cycles. The implications ripple across sectors reliant on clean energy, from transportation to power generation, signaling a pivotal stride towards sustainable futures.

This research, supported by the U.S. Department of Energy, marks a seminal milestone for the MAC Lab and the wider scientific community, consolidating the role of computationally-guided experimentation in innovating energy technologies. The publication in the esteemed journal Nature Chemical Engineering highlights the significance and timeliness of these findings amid global calls for intensified climate action. The collaborative efforts marrying computational prowess with hands-on validation showcase the power of interdisciplinary approaches in confronting some of the most urgent challenges of our era.

Worcester Polytechnic Institute continues its tradition of melding rigorous academics with solution-oriented research that addresses real-world problems. Through project-based learning and cutting-edge investigation, WPI empowers students and faculty alike to contribute meaningfully to sustainable scientific and technological advancements. This hydrogen catalysis initiative is but one facet of WPI’s broader commitment to pioneering clean energy transitions and fostering innovation ecosystems.

As the world embraces cleaner energy paradigms, the successful demonstration of plasma-assisted ammonia decomposition catalyzed by earth-abundant alloys paves the way for future commercialization and adoption. Continued research and development, dynamic scaling strategies, and integration with renewable electricity sources promise to further drive down costs and emissions. This work stands as a beacon of how emergent technologies can reshape the energy matrix, enabling hydrogen to truly fulfill its potential as a cornerstone of carbon neutrality.

Subject of Research: Not applicable
Article Title: Interpretable machine learning-guided plasma catalysis for hydrogen production
News Publication Date: 3-Oct-2025
Web References: https://www.nature.com/articles/s44286-025-00287-7
References: Worcester Polytechnic Institute, Dalian University of Technology, Northeastern University, U.S. Department of Energy
Image Credits: Worcester Polytechnic Institute
Keywords: Artificial intelligence, Hydrogen, Hydrogen production, Fuel, Chemical engineering, Carbon, Copper, Iron, Nickel, Chemical reactions, Computer modeling, Catalytic efficiency, Machine learning, Ammonia, Molybdenum, Plasma, Algorithms

The team from MIT has unveiled a scalable process that produces hydrogen gas through the reaction of aluminum sourced primarily from recycled soda cans with seawater. Central to this method’s viability is a “cradle-to-grave” life cycle analysis, meticulously conducted to understand the environmental impact of every stage — from mining or recycling the aluminum, through the chemical reaction itself, to fuel transportation and eventual consumption. This scrutiny ensures that the process’s carbon footprint truly aligns with green energy standards, delivering a performance on par with other renewable hydrogen technologies such as those powered by solar and wind.

At the heart of the chemical reaction is aluminum’s unique behavior in water. Normally, aluminum exposed to oxygen forms a robust oxide layer that protects it from reacting. But by treating aluminum with a gallium-indium alloy, a rare metal mixture, this protective shield is disrupted, enabling aluminum to engage directly with water molecules. This interaction breaks apart water molecules, generating aluminum oxide and releasing pure hydrogen gas. The elegance of this reaction lies in its simplicity and energy density. As lead researcher Aly Kombargi explains, the volume of hydrogen that can be generated from a small amount of aluminum fuel holds promise for meeting the substantial energy demands of vehicles powered by hydrogen.

The innovation does not end at the reaction itself. The presence of salt in seawater plays a dual role: it not only facilitates the chemical interaction but also precipitates the gallium-indium catalyst, allowing it to be recovered and reused. This recycling of the catalyst contributes to the process’s sustainability, reducing waste and limiting the consumption of rare metals. Such a closed-loop system is indicative of a carefully engineered method with commercialization and environmental responsibility deeply embedded in its design.

To quantify the environmental viability of this aluminum-seawater hydrogen production, the researchers utilized Earthster, a sophisticated online life cycle assessment tool. Earthster pulls from vast databases of industrial processes and product emissions to model the environmental impact comprehensively. The MIT team explored numerous scenarios, including those starting from primary aluminum mined fresh from the earth and those tapping into secondary aluminum sources like recycled soda cans. They also varied transportation logistics for both aluminum inputs and hydrogen outputs to capture the full range of potential emissions.

Among the dozen scenarios analyzed, one configuration stood out: using primarily recycled aluminum combined with seawater, while recovering and reusing the gallium-indium catalyst. This pathway demonstrated a carbon footprint of approximately 1.45 kilograms of carbon dioxide emitted per kilogram of hydrogen produced. To put this into perspective, common fossil-fuel-based hydrogen production methods emit nearly 11 kilograms of CO2 per kilogram of hydrogen, marking a dramatic reduction in greenhouse gas emissions. This result firmly places aluminum-seawater hydrogen production alongside other promising green hydrogen approaches, matching or even surpassing them in carbon efficiency.

Cost analysis further underscores the commercial promise of this method. The researchers estimate the price of producing hydrogen via this process to be roughly $9 per kilogram. This figure is competitive with existing green hydrogen production methods that depend on intermittent energy sources like wind and solar. Importantly, the process addresses several logistical challenges that have traditionally hampered hydrogen’s spread, notably through the transport of hydrogen fuel itself. Instead of moving volatile hydrogen gas, the proposed system allows transportation of pretreated aluminum pellets as a stable “hydrogen fuel,” which can be converted to hydrogen on demand at fueling stations typically situated near seawater sources.

An intriguing byproduct of the chemical reaction is boehmite, an aluminum oxide hydroxide mineral. This compound has commercial interest in semiconductor manufacturing and other industrial applications, suggesting the possibility of another revenue stream that could offset operational expenses. Recovering and selling boehmite after hydrogen production not only reduces waste but can further drive down the overall environmental and economic cost of the technology, aligning with principles of circular economy.

To showcase the practicality of their approach beyond theoretical modeling, the MIT team has developed a pilot reactor approximately the size of a water bottle. This compact device efficiently converts aluminum pellets and seawater into hydrogen with sufficient energy output to power an electric bike for several hours. This demonstration, coupled with previous successes in fueling small vehicles, indicates the scalability of the technology from micro to automotive scales. Researchers are also exploring expanding the application envelope to maritime domains, including underwater vehicles powered directly by hydrogen generated from surrounding seawater.

The significance of this technology extends beyond mere engineering novelty. Aly Kombargi highlights aluminum’s potential to become an essential player in clean energy systems by offering a feasible, scalable solution for hydrogen deployment in transportation and remote energy applications. The ability to utilize abundant materials like seawater combined with recycled aluminum could democratize access to green hydrogen, breaking reliance on rare or geographically constrained energy inputs.

MIT’s study, supported by the MIT Portugal Program, represents a pioneering step toward environmentally sustainable hydrogen. While challenges remain, including optimizing the reaction efficiency, catalyst recovery at scale, and supply chain logistics, the research provides a practical framework to harness existing materials and resources for clean energy. As the global community intensifies efforts to decarbonize, such innovations that balance technical feasibility, environmental responsibility, and cost-effectiveness will be indispensable.

Continued research and development efforts will aim to refine reactor designs and explore broader implications of this process in real-world energy systems. The vision of fueling not only vehicles but also remote installations or marine applications paints an encouraging picture for hydrogen’s role in a decarbonized future powered by everyday recycled materials and seawater — a testament to the ingenuity of converging chemistry and sustainability science.

Subject of Research: Hydrogen production using recycled aluminum and seawater for green energy applications

Article Title: “Life Cycle Assessment and Cost Analysis of Hydrogen Production via Aluminum-Seawater Reactions”

Web References:
https://news.mit.edu/2024/recipe-for-zero-emissions-fuel-with-cans-seawater-caffeine-0725
https://www.cell.com/cell-reports-sustainability/fulltext/S2949-7906(25)00103-X
http://dx.doi.org/10.1016/j.crsus.2025.100407

References:
Life Cycle Assessment and Cost Analysis of Hydrogen Production via Aluminum-Seawater Reactions, Cell Reports Sustainability, 2025

Image Credits: Courtesy of Douglas Hart, et al

Keywords

Fuel, Hydrogen fuel, Energy resources, Alternative energy, Carbon emissions, Pollutants, Vehicles, Electric vehicles, Energy, Sustainability, Transportation

Bismuth ferrite has garnered considerable attention for its potential as a photoelectrocatalyst capable of harnessing solar energy to drive the oxidation of water or biomass derivatives, thereby extracting hydrogen through photoelectron oxidation. The intrinsic functionality of these films lies in their ability to absorb solar photons and facilitate the separation of hydrogen atoms from water or organic compounds like glycerol and ethanol. However, the efficiency of this promising semiconductor film has historically been hampered by impurities—secondary phases that interfere with the material’s electronic and catalytic properties.

The challenge addressed by the research team was to devise a straightforward, low-cost approach for eliminating these detrimental compounds without resorting to expensive or environmentally taxing processes. During doctoral research led by Bruno Leuzinger da Silva at UNICAMP, under the mentorship of Professor Ana Flávia Nogueira, an unexpected discovery occurred: upon exposure to glycerol under illumination, the bismuth ferrite films underwent a spontaneous purification process. This serendipitous finding revealed that the material itself could be coaxed into self-cleaning, selectively removing the Bi₂O₃ phases when photoelectrochemical reactions were activated.

Further rigorous experimentation confirmed that the combination of light, electricity, and glycerol—a renewable, abundant, and biodegradable by-product of biodiesel production—instigated electrochemical transformations at the material’s surface that eradicated secondary phases, dramatically enhancing the photoelectrocatalytic performance. By immersing the films in glycerol and illuminating them, the researchers effectively ‘fine-tuned’ the material’s crystalline structure, resulting in higher phase purity and a corresponding improvement in hydrogen evolution efficiency.

This purification mechanism not only tackles the persistent bottleneck in the development of bismuth ferrite-based photoelectrodes but also introduces a paradigm shift in material processing for sustainable energy applications. It leverages benign inputs and mild conditions, standing in stark contrast to traditional methods that often require high-temperature annealing or chemical treatments involving hazardous substances. The eco-friendly nature of this approach aligns well with the overarching goals of green chemistry and sustainable technology development.

While the current performance of these purified Bi₂Fe₄O₉ films does not yet meet the benchmarks necessary for full-scale industrial application, the scientific breakthrough paves the way for extensive optimization and integration into photoelectrochemical reactors designed for green hydrogen production. Hydrogen generated through such environmentally compatible methods is poised to become an indispensable clean fuel, crucial in mitigating climate change and reducing dependence on fossil fuels.

Additionally, the implications of this discovery extend beyond hydrogen evolution. The production of high-purity, photoactive materials through such gentle electrochemical purification techniques holds promise for water purification processes, potentially allowing for the breakdown of organic pollutants in wastewater under solar irradiation. This opens avenues for multifunctional applications of the biocompatible ferrite films in environmental remediation.

Funding from major science foundations, including the São Paulo Research Foundation (FAPESP), as well as industrial partners like Shell, has enabled the multidisciplinary investigation that integrates expertise from materials chemistry, chemical engineering, and renewable energy technologies. Strategic collaboration across these domains fosters not only the advancement of photoelectrocatalytic materials but also their translation into practical, scalable solutions.

The detailed findings are documented in an upcoming publication in the journal Electrochimica Acta, where the team outlines the mechanistic insights into phase removal and enhanced catalytic activity. This work is a testament to how careful observation, combined with fundamental chemical knowledge, can yield transformative solutions to pressing energy challenges.

To summarize, the study demonstrates the ability to utilize simple, sustainable reagents under mild photoelectrochemical conditions to achieve a level of material purity previously inaccessible or prohibitively expensive. This brings the scientific community a step closer to realizing efficient solar-driven hydrogen production using advanced photoelectrode materials. The interplay of light-driven reactions and material self-purification signals a future where smart material engineering will seamlessly integrate with sustainable industrial processes.

As the global energy landscape pivots toward renewable sources, innovations such as this highlight the critical role of interdisciplinary research centers like CINE. By fostering groundbreaking science combined with practical application insights, they are molding the future of clean energy and environmental technologies. Continuous efforts to enhance film stability, catalytic turnover, and integration with photoelectrochemical systems will undoubtedly follow, spurred by these promising initial results.

In conclusion, the photoelectrochemical purification of Bi₂Fe₄O₉ thin films exemplifies how combining fundamental science with a deep understanding of material interfaces can unlock green technological advancements. The successful removal of secondary phases using glycerol and light not only enhances hydrogen evolution but also establishes a platform for designing next-generation photoactive materials geared toward a sustainable hydrogen economy and water treatment.

Subject of Research:
Development of a photoelectrochemical purification method for mullite-type bismuth ferrite (Bi₂Fe₄O₉) thin films enhancing green hydrogen production.

Article Title:
Photoelectrochemical Bi2Fe4O9 phase purification – Removing the phase Bi2O3 from Bi2Fe4O9/Bi2O3 thin films

News Publication Date:
12-Feb-2025

Web References:
https://www.cine.org.br/en/
https://www.sciencedirect.com/science/article/abs/pii/S0013468625002154?via%3Dihub

References:
Fernández P.S. et al. (2025) Electrochimica Acta, DOI: 10.1016/j.electacta.2025.145852.

Image Credits:
CINE

Keywords

Hydrogen production, Photocatalysis, Perovskites, Photoelectrons, Catalysis, Electrochemistry

At the heart of this project lies the innovative production of turquoise hydrogen, which is extracted through the process of natural gas pyrolysis. Unlike traditional methods of hydrogen generation, which often result in the emission of carbon dioxide, this new method seeks to revolutionize hydrogen production by utilizing the abundant natural gas reserves found in regions such as the Marcellus Shale and the Appalachian Basin. Such an approach not only addresses environmental concerns but also aims to make hydrogen a more accessible energy source for various applications.

Sheima Khatib, an associate professor of chemical engineering and one of the leading researchers in this project, highlighted the strategic significance of using natural gas. Describing it as a relatively cleaner fossil fuel compared to oil, she emphasizes that converting it into hydrogen represents a dual opportunity: it is a clean energy carrier for power generation and serves as a crucial feedstock for a multitude of industrial processes. Through this initiative, Khatib and her team are not merely focusing on energy generation; they are paving the way for industrial applications that can benefit from cleaner production methods.

The project is designed with multiple goals, each aimed at reinforcing Virginia’s role in energy innovation. Firstly, it aims to establish a globally recognized hydrogen innovation hub. This involves advancing techniques for catalytic methane decomposition, a method that promises to create hydrogen while simultaneously producing solid carbon—a versatile substance with numerous industrial applications. Moreover, there’s a clear emphasis on promoting regional partnerships, which will spur economic development, diversify local industries, and foster entrepreneurial activities within the region.

In addition to economic outcomes, the project also seeks to develop a highly skilled workforce that is well-prepared for futures in chemical manufacturing and energy sectors. Academic and industrial collaborations are being prioritized to cultivate talent in emerging energy technologies, especially in rural areas where such educational advancements can have transformative effects. By reaching out to K-12 educational systems, the initiative aims to enhance energy literacy among students, creating pathways for them to engage in fields associated with sustainable energy technologies.

Khatib’s innovative research focuses on catalytic methane decomposition—an efficient process that transforms methane, the main component of natural gas, into hydrogen and solid carbon via the action of a catalyst. This method ensures that production occurs without releasing harmful carbon dioxide emissions, presenting a significant advancement in the quest for cleaner hydrogen generation. The clean hydrogen produced can be utilized in fuel cells, which have gained attention for their potential in creating electricity with mere water being their only byproduct—a stark contrast to traditional fossil fuel usage.

The implications of this research extend beyond energy generation; they touch upon various critical industrial processes. Hydrogen’s role in ammonia synthesis for fertilizers, petroleum refining, and methanol production renders it indispensable in numerous sectors. Additionally, the solid carbon byproduct of the process presents opportunities for advanced materials development, thereby adding value to what would otherwise be a waste product.

By targeting the dual issues of greenhouse gas emissions and energy production, Khatib and her team are working to transform methane, a potent greenhouse gas, into high-value products. This shift not only contributes to environmental remediation but also presents strategic opportunities for economic asset creation within local communities, ultimately promoting sustainable practices within the region’s energy landscape.

Partnering with industry leaders and academic professionals is a crucial component of this initiative. Notable collaborators include Amy Price Azano, an expert in rural education, who will spearhead workforce development components, and Wilson Shafer, an assistant professor of chemistry at Asbury University. Together, these professionals will forge partnerships aimed at bridging the gap between advanced research and practical implementation within the Appalachian region’s carbon and hydrogen value chains.

The project emphasizes robust market analysis and feasibility studies driven by industry collaboration. Hart, R&D leader at Shepherd Chemical Company, has expressed enthusiasm for the project’s potential to transition laboratory innovations into successful commercial applications. By addressing technical challenges and exploring pathways for technology transfer, the team aims to ensure that breakthroughs in catalytic methane decomposition can resonate in the business sphere, ultimately achieving a real societal impact.

As the initiative progresses, the educational aspect remains a vital thread woven into its fabric. With programs designed for K-12 teachers, the project aspires to foster excitement around sustainable energy technologies among younger generations. This sustained engagement is crucial not only for workforce development but also for instilling a culture of sustainability within rural communities that can ultimately lead to widespread environmental benefits.

By promoting a collaborative approach that integrates essential stakeholders in educational and industrial sectors, the project aspires to create a comprehensive ecosystem that supports sustainable energy practices while driving economic growth. This multifaceted initiative sets the stage for a new era of energy in Virginia, one where clean hydrogen production is synonymous with innovation, economic revitalization, and environmental stewardship.

The implications of Virginia Tech’s initiative are profound, as the project stands at the intersection of advanced scientific research, community engagement, and economic development. As Sheima Khatib articulates, the overarching goal is to contribute significantly to regional and national energy security while paving the way for sustainable energy solutions that can alter the trajectory of energy production and use in Virginia and beyond.

Through a blend of cutting-edge research, community engagement, and educational initiatives, this project exemplifies how scientific innovation can be harnessed to address the pressing energy and environmental challenges of our time, promising a cleaner, more sustainable future driven by local resources and expertise.

Subject of Research: Natural gas conversion and hydrogen production
Article Title: Virginia Tech Leads the Charge in Hydrogen Innovation
News Publication Date: October 2023
Web References:
References:
Image Credits: Photo by Hailey Wade for Virginia Tech

Keywords: Hydrogen production, Natural gas conversion, Turquoise hydrogen, Sustainable energy, Economic development, Workforce development, Catalytic methane decomposition, Environmental stewardship, Clean energy solutions, Virginia Tech.