Advances in Hydrogen Energy

Topic Information

Dear Colleagues,

Hydrogen energy research and development has attracted growing attention as it is one of the key solutions for achieving a clean energy system in the future. To reduce greenhouse gas emissions, national governments across the world are developing ambitious policies to support hydrogen technology, and an increasing level of funding has been allocated for projects that research, develop, and demonstrate this technology. At the same time, the private sector is capitalizing on this opportunity through larger investments in hydrogen technology solutions.

While intense research activities have been dedicated to this field, several issues require further research prior to achieving the full commercialization of hydrogen technology solutions. This Topic will contribute to disseminating the most recent advancements in the field with respect to both modeling and experimental analysis. The focus is placed on research covering all aspects of the hydrogen energy route, including fuel production, storage, transportation, and final usage. This also includes the development of hydrogen-based fuels, such as ammonia, alcohols, and methane.

We look forward to receiving your submissions.

Dr. Samuel Simon Araya
Dr. Vincenzo Liso
Topic Editors

Keywords

Participating Journals

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Catalysts catalysts	4.0	7.6	2011	15.9 Days	CHF 2200	Submit
Energies energies	3.2	7.3	2008	16.8 Days	CHF 2600	Submit
Hydrogen hydrogen	3.0	5.5	2020	17 Days	CHF 1200	Submit
Processes processes	2.8	5.5	2013	14.9 Days	CHF 2400	Submit
Sustainability sustainability	3.3	7.7	2009	17.9 Days	CHF 2400	Submit

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Published Papers (8 papers)

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All Catalysts Energies Hydrogen Processes Sustainability

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17 pages, 1780 KB  

Open AccessArticle

Polyaniline-Encapsulated Cu-NA-MOFs: Facile Synthesis and Dual-Role Electrocatalytic Activity

by Hussain S. AlShahrani, Hadi M. Marwani, Khalid A. Alzahrani, Kahkashan Anjum and Anish Khan

Catalysts 2026, 16(4), 370; https://doi.org/10.3390/catal16040370 - 21 Apr 2026

Viewed by 325

Abstract

The world’s growing need for energy, fueled by industrial expansion and a rising population, continues to be a challenge for the scientific community. The heavy reliance on fossil fuels that contribute to environmental degradation and public health concerns, is shifting toward sustainable alternatives, [...] Read more.

The world’s growing need for energy, fueled by industrial expansion and a rising population, continues to be a challenge for the scientific community. The heavy reliance on fossil fuels that contribute to environmental degradation and public health concerns, is shifting toward sustainable alternatives, with hydrogen production via advanced catalysts as an energy source emerging as a promising solution. This transition addresses the challenges posed by harmful combustion emissions. In this study, we developed an innovative PANI@Cu-NA-MOF nanocomposite catalyst through a sol–gel synthesis approach that strategically integrates conducting polymers with metal–organic frameworks. The catalyst was characterized using different sets of techniques. Surface morphology and elemental composition were investigated using SEM-EDX, while structural analysis was carried out with FTIR that helped to identify the chemical bonds and functional groups, and UV-Vis spectroscopy provided information on its light absorption properties. In addition, TGA was used to evaluate thermal behavior, and XPS offered detailed surface chemical analysis. It was observed by morphology that PANI@Cu-NA-MOF is a noncapsular-like structure. It is thermally highly stable; a TGA study showed that up to 550 °C, almost 2.5% of weight was lost. The single peak in UV-Vis is the preparation of a successful composite. XPS and FTIR reveal the required peaks of functional groups and elements. The PANI@Cu-NA-MOF composite turned out to be quite effective for water electrolysis, requiring an overpotential of just 0.47 V to drive the reaction. When tested against the reversible hydrogen electrode, we observed onset potentials of 1.6 V/RHE for the oxygen evolution reaction and 0.2 V/RHE for the hydrogen evolution reaction. What makes this particularly interesting is that such performance significantly cuts down on the energy needed for electrolysis, which could make hydrogen production much more practical. Since hydrogen burns cleanly and offers a real alternative to fossil fuels, having an efficient catalyst like this brings us one step closer to sustainable energy. Full article

(This article belongs to the Topic Advances in Hydrogen Energy)

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21 pages, 4982 KB  

Open AccessArticle

Evolution of Hydrogen Evolution Reaction Catalytic Performance of Electrodeposited Nickel Electrodes

by Zhiyang Yao, Chunjuan Huang and Zhongwei Wang

Hydrogen 2026, 7(2), 47; https://doi.org/10.3390/hydrogen7020047 - 3 Apr 2026

Viewed by 638

Abstract

Despite the long-standing recognition of nickel as an effective electrocatalyst for the alkaline hydrogen evolution reaction (HER), the majority of extant studies primarily focus on initial catalytic performance or short-term stability under relatively low current densities. In practical alkaline water electrolysis, however, electrodes [...] Read more.

Despite the long-standing recognition of nickel as an effective electrocatalyst for the alkaline hydrogen evolution reaction (HER), the majority of extant studies primarily focus on initial catalytic performance or short-term stability under relatively low current densities. In practical alkaline water electrolysis, however, electrodes operate continuously at elevated current densities for extended periods, where surface chemical states and electrochemical responses may evolve dynamically. A systematic understanding of such time-dependent behaviour remains limited, particularly for electrodeposited nickel under sustained operation. In this study, the long-term HER performance of electrodeposited Ni electrodes at a current density of 100 mA cm⁻² over 120 h is investigated. The objective of this study is to correlate the evolution of electrochemical performance with changes in surface chemical states during prolonged electrolysis. To this end, a combination of methods was employed, including polarization measurements, electrochemical impedance analysis, double-layer capacitance evaluation, and ex situ surface characterization. In contrast to the tendency to prioritize absolute enhancement of activity, this study places greater emphasis on the transient decline–recovery–stabilization behaviour that is observed during operation. Furthermore, it discusses the potential relationship of this behaviour with surface hydroxylation and restructuring processes. The present study utilizes a time-resolved analysis to elucidate the dynamic surface evolution of nickel electrodes under practical alkaline HER conditions, thereby underscoring the significance of evaluating catalyst durability beyond the confines of short-term measurements. The findings presented herein contribute to a more realistic assessment of nickel-based electrodes for alkaline water electrolysis applications. Full article

(This article belongs to the Topic Advances in Hydrogen Energy)

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23 pages, 2495 KB  

Open AccessArticle

Combustion Characterization and Heat Loss Determination Through Experimental Investigation of Hydrogen Internal Combustion Engine

by Andrew Fenech, Stefan Portelli, Emiliano Pipitone and Mario Farrugia

Energies 2026, 19(6), 1424; https://doi.org/10.3390/en19061424 - 12 Mar 2026

Viewed by 596

Abstract

Hydrogen combustion is known to be fast compared to traditional hydrocarbon fuels. The fast combustion leads to a higher thermal efficiency. In this research a 600 cc single cylinder hydrogen engine was tested at 1250 rpm, lambda = 2 and 3, and three [...] Read more.

Hydrogen combustion is known to be fast compared to traditional hydrocarbon fuels. The fast combustion leads to a higher thermal efficiency. In this research a 600 cc single cylinder hydrogen engine was tested at 1250 rpm, lambda = 2 and 3, and three load levels (load was represented by Manifold Absolute Pressure (MAP); MAPs tested were 75, 95 and 120 kPa) and compared to operation with gasoline and propane. The fast burn duration (Mass Fraction Burnt MFB10% to MFB90%) and the MFB 50% were determined and analyzed. The hydrogen MFB50% location for Minimum Timing for Best Torque (MBT) was found to occur at around the typical 8 Crank Angle Degrees (CADs) After Top Dead Center (ATDC). Measurements of ignition delay based on the fast data direct measurement of spark ignition coil current drop to the change in polarity of net heat release are presented. With shifts towards direct injection and higher injection pressures, consideration was given to the hydrogen pressurization penalty, where it was calculated that pressurizing hydrogen to 100 bar at the flow required for lambda = 2 operation is 2.3 bar, i.e., higher than the Friction Mean Effective Pressure (FMEP)! Furthermore, hydrogen is widely cited to have a higher heat loss than typical hydrocarbon fuels. In this paper, detailed analyses at lambda 2 and lambda 3 showed that hydrogen in fact has lower heat losses. Full article

(This article belongs to the Topic Advances in Hydrogen Energy)

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20 pages, 2681 KB  

Open AccessArticle

Deep-Reinforcement-Learning-Based Energy Management for Off-Grid Wind-to-Hydrogen Systems

by Bo Zhou, Yuan Gao, Xiaoxu He, Yiyina Teng, Ning Wang, Baocheng Wang and Xiaofei Song

Sustainability 2026, 18(5), 2408; https://doi.org/10.3390/su18052408 - 2 Mar 2026

Cited by 1 | Viewed by 486

Abstract

Off-grid wind-to-hydrogen systems are considered a promising solution for sustainable, large-scale green hydrogen production in remote areas. However, under the combined effects of highly fluctuating wind generation and stochastic load variations, existing energy management methods still face a challenge: in off-grid wind-to-hydrogen systems, [...] Read more.

Off-grid wind-to-hydrogen systems are considered a promising solution for sustainable, large-scale green hydrogen production in remote areas. However, under the combined effects of highly fluctuating wind generation and stochastic load variations, existing energy management methods still face a challenge: in off-grid wind-to-hydrogen systems, intelligent energy management studies that jointly address economic performance and operational stability are still limited. To address these issues, this paper develops a mathematical model for an off-grid wind-to-hydrogen system to reveal the coupling characteristics of the wind–electricity–hydrogen conversion process. Building on this model, a deep-reinforcement-learning-based energy management strategy is proposed. By formulating objectives that simultaneously capture economic benefits and stability requirements, the proposed strategy enables adaptive power flow allocation and dynamic optimization under uncertainty. Case studies demonstrate that, while fully satisfying load demand, the proposed strategy can significantly improve renewable energy utilization and hydrogen production, thereby increasing profit and ensuring stable and sustainable system operation. Full article

(This article belongs to the Topic Advances in Hydrogen Energy)

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33 pages, 6733 KB  

Open AccessReview

Contribution of Severe Plastic Deformation via High-Pressure Torsion to the Hydrogen Cycle: From Hydrogen Production and Storage to Hydrogen Embrittlement

by Kaveh Edalati

Hydrogen 2026, 7(1), 23; https://doi.org/10.3390/hydrogen7010023 - 4 Feb 2026

Viewed by 823

Abstract

Hydrogen is a key energy carrier for achieving carbon neutrality, yet its widespread deployment is hindered by challenges associated with efficient hydrogen production, safe and reversible hydrogen storage, and hydrogen-induced embrittlement. Severe plastic deformation processes, particularly high-pressure torsion (HPT), have emerged as a [...] Read more.

Hydrogen is a key energy carrier for achieving carbon neutrality, yet its widespread deployment is hindered by challenges associated with efficient hydrogen production, safe and reversible hydrogen storage, and hydrogen-induced embrittlement. Severe plastic deformation processes, particularly high-pressure torsion (HPT), have emerged as a powerful approach capable of addressing these challenges through extreme grain refinement, defect engineering, phase stabilization far from equilibrium, and synthesis of novel materials. This article reviews the impact of HPT on hydrogen-related materials, covering hydrogen production, hydrogen storage, and hydrogen embrittlement resistance. For hydrogen production, HPT enables the synthesis of nanostructured, defect-rich, and compositionally complex compounds, including high-entropy oxides and oxynitrides, which exhibit enhanced hydrolytic, electrocatalytic, photocatalytic, photoelectrocatalytic, and photoreforming performance. For hydrogen storage, HPT fundamentally modifies hydrogenation activation and kinetics, and modifies thermodynamics by hydrogen binding energy engineering, enabling reversible hydrogen storage at room temperature in systems such as Mg-based and high-entropy alloys. For hydrogen embrittlement resistance, HPT under optimized conditions suppresses hydrogen-assisted fracture by engineering ultrafine grains and defects (vacancies, dislocations, Lomer–Cottrell locks, D-Frank partial dislocations, stacking faults, twins, and grain boundaries) that control hydrogen diffusion, trapping, and strain localization. By integrating insights across these three domains, this article highlights HPT as a transformative strategy for developing next-generation hydrogen materials and identifies key opportunities for future research at the intersection of severe plastic deformation and hydrogen technologies. Full article

(This article belongs to the Topic Advances in Hydrogen Energy)

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14 pages, 1779 KB  

Open AccessFeature PaperEditor’s ChoiceArticle

Electro-Reforming of Biomass Gasification Tar with Simultaneous Hydrogen Evolution

by Umberto Calice, Francesco Zimbardi, Nadia Cerone and Vito Valerio

Processes 2026, 14(3), 444; https://doi.org/10.3390/pr14030444 - 27 Jan 2026

Viewed by 657

Abstract

In this study, an electrochemical valorization strategy on liquid byproducts from hazelnut shell gasification was developed to couple waste remediation with energy-efficient hydrogen production. The aqueous phase, rich in organic compounds, is processed in an anion exchange membrane (AEM) cell, where pure hydrogen [...] Read more.

In this study, an electrochemical valorization strategy on liquid byproducts from hazelnut shell gasification was developed to couple waste remediation with energy-efficient hydrogen production. The aqueous phase, rich in organic compounds, is processed in an anion exchange membrane (AEM) cell, where pure hydrogen evolved at the cathode while organic pollutants are oxidized at the anode. First, the feedstock is thoroughly characterized using gas chromatography–mass spectrometry (GC-MS), identifying a complex matrix of water-soluble aromatic compounds such as phenols, catechols, and other aromatics compounds, with concentrations reaching up to 2.9 g/kg for catechols. Then, the electro-reforming process is optimized using Nickel oxide–hydroxide (Ni(O)OH) electrodes with a loading of 0.75 mg/cm². This methodology relies on the favorable thermodynamics of organic oxidation, which requires a lower onset potential (0.4 V) compared to the oxygen evolution reaction (OER) observed in the alkaline control (0.52 V), and the low overpotential of the Nickel oxide–hydroxide electrode towards the oxidized species. Consequently, the organic load undergoes progressive oxidation into hydrophilic and less bioaccumulating species and carbon dioxide, allowing for the simultaneous generation of pure hydrogen at the cathode at a reduced cell voltage. Elevated stability was observed, with a substantial abatement—78% of the initial organic load—of organic compounds achieved over 80 h at a fixed cell voltage of 0.5 V, and a specific energy consumption for hydrogen production of $38.5 \mathrm{M}\mathrm{J}\cdot {\mathrm{k}\mathrm{g}}_{{\mathrm{H}}_2}^{-1}$. This represents a step forward in the development of technologies that reduce the energy intensity of hydrogen generation while valorizing biomass gasification residues. Full article

(This article belongs to the Topic Advances in Hydrogen Energy)

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19 pages, 3988 KB  

Open AccessArticle

Fuel Cell Micro-CHP: Analysis of Hydrogen Solid Storage and Artificial Photosynthesis Hydrogen Production

by Saad Fahim, Taoufiq Kaoutari, Guillaume Foin and Hasna Louahlia

Hydrogen 2026, 7(1), 5; https://doi.org/10.3390/hydrogen7010005 - 2 Jan 2026

Viewed by 1077

Abstract

This paper investigates three distinct hydrogen-related subsystems: production, storage, and the use. An analysis of the micro-combined heat and power production (mCHP) behavior using natural gas is conducted to understand how the system operates under different conditions and to evaluate its yearly performance. [...] Read more.

This paper investigates three distinct hydrogen-related subsystems: production, storage, and the use. An analysis of the micro-combined heat and power production (mCHP) behavior using natural gas is conducted to understand how the system operates under different conditions and to evaluate its yearly performance. To reduce CO₂ emissions, hydrogen fuel consumption is proposed, and an emission analysis under different fuel-supply configurations is performed. The results show that hydrogen produced by artificial photosynthesis has the lowest CO₂ impact. Therefore, the paper examines this process and its main characteristics. An engineering model is proposed to rapidly estimate the mean volumetric hydrogen production rate. To ensure safe coupling between hydrogen production and mCHP demand, the study then focuses on solid-state hydrogen storage. Subsequently, in this framework, the state of charge (SOC) is defined as the central control variable linking storage thermodynamics to hydrogen delivery. Accurate SOC estimation ensures that the storage unit can supply the required hydrogen flow without causing starvation, pressure drops, or thermal drift during CHP operation. The proposed SOC estimation method is based on an analytical approach and experimentally validated while relying solely on external measurements. The overall objective is to enable a coherent, low-carbon, and safely controllable hydrogen-based mCHP system. Full article

(This article belongs to the Topic Advances in Hydrogen Energy)

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13 pages, 925 KB  

Open AccessArticle

Analysis of Exergy Flow and CCUS Carbon Reduction Potential in Coal Gasification Hydrogen Production Technology in China

by Lixing Zheng, Xuhui Jiang, Song Wang, Jiajun He, Yuhao Wang, Linbin Hu, Kaiji Xie and Peng Wang

Energies 2025, 18(22), 5906; https://doi.org/10.3390/en18225906 - 10 Nov 2025

Cited by 2 | Viewed by 969

Abstract

Coal constitutes China’s most significant resource endowment at present. Utilizing coal resources for hydrogen production represents an early-stage pathway for China’s hydrogen production industry. The analysis of energy quality and carbon emissions in coal gasification-based hydrogen production holds practical significance. This paper integrates [...] Read more.

Coal constitutes China’s most significant resource endowment at present. Utilizing coal resources for hydrogen production represents an early-stage pathway for China’s hydrogen production industry. The analysis of energy quality and carbon emissions in coal gasification-based hydrogen production holds practical significance. This paper integrates the exergy analysis methodology into the traditional LCA framework to evaluate the exergy and carbon emission scales of coal gasification-based hydrogen production in China, considering the technical conditions of CCUS. This paper found that the life cycle exergic efficiency of the whole chain of gasification-based hydrogen production in China is accounted to be 38.8%. By analyzing the causes of exergic loss and energy varieties, it was found that the temperature difference between the reaction of coal gasification and CO conversion unit and the pressure difference due to the compressor driven by the electricity consumption of the compression process in the variable pressure adsorption unit are the main causes of exergic loss. Corresponding countermeasures were suggested. Regarding decarbonization strategies, the CCUS process can reduce CO₂ emissions across the life cycle of coal gasification-based hydrogen production by 48%. This study provides an academic basis for medium-to-long-term forecasting and roadmap design of China’s hydrogen production structure. Full article

(This article belongs to the Topic Advances in Hydrogen Energy)

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