United States

High-temperature proton exchange membranes (HT-PEMs) for fuel cells are considered transformative technologies for efficient energy conversion particularly in hydrogen-based transportation owing to their ability to deliver high power density and operational efficiency in harsh environments. However several critical challenges limit their broader adoption notably the limited durability and high costs associated with core components such as membranes and electrocatalysts under elevated temperature conditions. This review systematically addresses these challenges by examining the role of engineered nanomaterials in overcoming performance and stability limitations. The potential of nanomaterials to improve catalytic activity proton conductivity and thermal stability is discussed in detail emphasizing their impact on the optimization of catalyst layer composition including catalysts binders phosphoric acid electrolytes and additives. Recent advancements in nanostructured assemblies and 3D morphologies are explored to enhance fuel cell efficiency through synergistic interactions of these components. Additionally ongoing issues such as catalyst degradation long-term stability and resistance to high-temperature operation are critically analyzed. This manuscript offers a comprehensive overview of current HT-PEMs research and proposes future material design strategies that could bridge the gap between laboratory prototypes and large-scale industrial applications.

We combine state-of-the-art thermo-metallurgical welding process modeling with coupled diffusion-elastic– plastic phase field fracture simulations to predict the failure states of hydrogen transport pipelines. This enables quantitatively resolving residual stress states and the role of brittle hard regions of the weld such as the heat affected zone (HAZ). Failure pressures can be efficiently quantified as a function of asset state (existing defects) materials and weld procedures adopted and hydrogen purity. Importantly simulations spanning numerous relevant conditions (defect size and orientations) are used to build Virtual Failure Assessment Diagrams (FADs) enabling a straightforward uptake of this mechanistic approach in fitness-for-service assessment. Model predictions are in very good agreement with FAD approaches from the standards but show that the latter are not conservative when resolving the heterogeneous nature of the weld microstructure. Appropriate mechanistic FAD safety factors are established that account for the role of residual stresses and hard brittle weld regions.

Green hydrogen is gaining global attention as a zero-carbon energy carrier with the potential to drive sustainable energy transitions particularly in regions facing rising fossil fuel costs and resource depletion. In sub-Saharan Africa financing mechanisms and structured off-take agreements are critical to attracting investment across the green hydrogen value chain from advisory and pilot stages to full-scale deployment. While substantial funding is required to support a green economic transition success will depend on the effective mobilization of capital through smart public policies and innovative financial instruments. This review evaluates financing mechanisms relevant to sub-Saharan Africa including green bonds public–private partnerships foreign direct investment venture capital grants and loans multilateral and bilateral funding and government subsidies. Despite their potential current capital flows remain insufficient and must be significantly scaled up to meet green energy transition targets. This study employs a mixed-methods approach drawing on primary data from utility firms under the H2Atlas-Africa project and secondary data from international organizations and the peer-reviewed literature. The analysis identifies that transitioning toward Net-Zero emissions economies through hydrogen development in sub-Saharan Africa presents both significant opportunities and measurable risks. Specifically the results indicate an estimated investment risk factor of 35% reflecting potential challenges such as financing infrastructure and policy readiness. Nevertheless the findings underscore that green hydrogen is a viable alternative to fossil fuels in subSaharan Africa particularly if supported by targeted financing strategies and robust policy frameworks. This study offers practical insights for policymakers financial institutions and development partners seeking to structure bankable projects and accelerate green hydrogen adoption across the region.

Hydrogen is widely recognized as a key enabler of the clean energy transition but the lack of safe efficient and scalable storage technologies continues to hinder its broad deployment. Conventional hydrogen storage approaches such as compressed hydrogen storage cryo-compressed hydrogen storage and liquid hydrogen storage face limitations including high energy consumption elevated cost weight and safety concerns. In contrast solid-state hydrogen storage using carbon-based adsorbents has gained growing attention due to their chemical tunability low cost and potential for modular integration into energy systems. This review provides a comprehensive evaluation of hydrogen storage using carbon-based materials covering fundamental adsorption mechanisms classical materials emerging architectures and recent advances in computationally AI-guided material design. We first discuss the physicochemical principles driving hydrogen physisorption chemisorption Kubas interaction and spillover effects on carbon surfaces. Classical adsorbents such as activated carbon carbon nanotubes graphene carbon dots and biochar are evaluated in terms of pore structure dopant effects and uptake capacity. The review then highlights recent progress in advanced carbon architectures such as MXenes three-dimensional architectures and 3D-printed carbon platforms with emphasis on their gravimetric and volumetric performance under practical conditions. Importantly this review introduces a forward-looking perspective on the application of artificial intelligence and machine learning tools for data-driven sorbent design. These methods enable high-throughput screening of materials prediction of performance metrics and identification of structure– property relationships. By combining experimental insights with computational advances carbon-based hydrogen storage platforms are expected to play a pivotal role in the next generation of energy storage systems. The paper concludes with a discussion on remaining challenges utilization scenarios and the need for interdisciplinary efforts to realize practical applications.

Hydrogen (H2) will play a vital role in the global shift towards sustainable energy systems. Due to the high cost and challenges associated with storing hydrogen in large quantities for industrial applications Underground Hydrogen Storage (UHS) in geological formations has emerged as a promising solution. Clay minerals abundant in subsurface environments play a critical role in UHS by providing low permeability cation exchange capacity and stability essential for preventing hydrogen leakage. However microorganisms in the subsurface particularly hydrogenotrophic species interact with clay minerals in ways that can affect the integrity of these storage systems. Microbes form biofilms on clay surfaces which can cause pore clogging and reduce the permeability of the reservoir potentially stabilizing H2 storage and limiting injectivity. Microbial-induced chemical weathering through the production of organic acids and redox reactions can degrade clay minerals releasing metal ions and destabilizing the storage site. These interactions raise concerns about the long-term storage capacity of UHS as microbial processes could lead to H2 loss and caprock degradation compromising the storage system’s effectiveness. This mini review aims to cover the current understanding of the interactions between clay minerals and microorganisms and how these dynamics can affect the safe and sustainable deployment of UHS.

Today hydrogen (H2) is overwhelmingly produced through steam methane reforming (SMR) of natural gas which emits about 12 kg of carbon dioxide (CO2) for 1 kg of H2 (∼12 kg-CO2/kg-H2). Water electrolysis offers an alternative for H2 production but today’s electrolyzers consume over 55 kWh of electricity for 1 kg of H2 (>55 kWh/kg-H2). Electric grid-powered water electrolysis would emit less CO2 than the SMR process when the carbon intensity for grid power falls below 0.22 kg-CO2/kWh. Solar- and wind-powered electrolytic H2 production promises over 80% CO2 reduction over the SMR process but large-scale (megawatt to gigawatt) direct solar- or wind-powered water electrolysis has yet to be demonstrated. In this paper several approaches for solar-powered electrolysis are analyzed: (1) coupling a photovoltaic (PV) array with an electrolyzer through alternating current; (2) direct-current (DC) to DC coupling; and (3) direct DC-DC coupling without a power converter. Co-locating a solar or wind farm with an electrolyzer provides a lower power loss and a lower upfront system cost than long-distance power transmission. A load-matching PV system for water electrolysis enables a 10%–50% lower levelized cost of electricity than the other systems and excellent scalability from a few kilowatts to a gigawatt. The concept of maximum current point tracking is introduced in place of maximum power point tracking to maximize the H2 output by solarpowered electrolysis.

Hydrogen storage remains the main barrier to the broader use of hydrogen as an energy carrier despite hydrogen’s high energy density and clean combustion. This study presents a comparative evaluation of conventional and emerging storage methods integrating thermodynamic kinetic economic and environmental metrics to assess capacity efficiency cost and reversibility. Physisorption analysis reveals that metal organic frameworks can achieve storage capacities up to 14.0 mmol/g. Chemical storage systems are evaluated including nanostructured MgH2 (7.6 wt%) catalyzed reversible complex hydrides liquid organic hydrogen carriers and clathrate hydrates. Techno-economic analysis shows storage costs from $500–700/kg H2 to $30–50/kg H2 with energy efficiencies of 50%–90%. Life cycle assessment identifies manufacturing as the primary source of emissions with carbon footprints varying from 150 to 2057 kg CO2 -eq/kg H2 . Cryo-compressed is the most practical transportation option while metal hydrides suit stationary use. This study provides a quantitative foundation to guide material selection and system design for next-generation hydrogen storage technologies.

Materials-based H2 storage plays a critical role infacilitating H2 as a low-carbon energy carrier but there remainslimited guidance on the technical performance necessary for specificapplications. Metal−organic framework (MOF) adsorbents haveshown potential in power applications but need to demonstrateeconomic promises against incumbent compressed H2 storage.Herein we evaluate the potential impact of material propertiescharge/discharge patterns and propose targets for MOFs’ deploy-ment in long-duration energy storage applications including backupload optimization and hybrid power. We find that state-of-the-artMOF could outperform cryogenic storage and 350 bar compressedstorage in applications requiring ≤8 cycles per year but need ≥5 g/Lincrease in uptake to be cost-competitive for applications thatrequire ≥30 cycles per year. Existing challenges include manufacturing at scale and quantifying the economic value of lower-pressure storage. Lastly future research needs are identified including integrating thermodynamic effects and degradation mechanisms.

The teams sits down with Johannah Christensen to discuss regulatory policies and risk mitigation for vessel owners switching to green fuels and what we can do to encourage that jump as well as ensure a Just Transition.

The podcast can be found on their website.

Photoelectrochemical (PEC) water splitting is a promising technology for green hydrogen production by harnessing solar energy. Traditionally this sustainable approach is studied under light intensity of 100 mW/cm2 mimicking the natural solar irradiation at the Earth’s surface. Sunlight can be easily concentrated using simple optical systems like Fresnel lens to enhance charge carrier generation and hydrogen production in PEC water splitting. Despite the great potentials this strategy has not been extensively studied and faces challenges related to the stability of photoelectrodes. To prompt the investigations and applications this work outlines the best practices and protocols for conducting PEC solar water splitting under concentrated sunlight illumination incorporating our recent advancements and providing some experimental guidelines. The key factors such as light source calibration photoelectrode preparation PEC cell configuration and long-term stability test are discussed to ensure reproducible and high performance. Additionally the challenges of the expected photothermal effect and the heat energy utilization strategy are discussed.