Pub Date : 2026-03-11Epub Date: 2026-02-09DOI: 10.1016/j.ijhydene.2026.153940
Yunus Emre Yuksel , Fatih Yilmaz , Murat Ozturk
In this study, a comprehensive thermodynamic analysis of an integrated solar tower-based multigeneration system planned for the purpose of electricity, hydrogen, heating, cooling and freshwater production. The design of the system consists of a solar tower receiver with Rankine and Organic Rankine power cycles, a hydrogen production and storage unit, an absorption refrigeration system and a freshwater production plant. In the analysis part of the study, a detailed thermodynamic analysis is performed and to see the effects of basic design parameters such as reference temperature, solar irradiance, molten-salt temperature and electrolyzer efficiency, parametric analyses were calculated. For the basic design parameters, the overall energetic and exergetic efficiencies were found to be 55.29% and 51.18%. The overall exergy destruction rate of the system was calculated as 12.3 MW, mainly occurred in Rankine and hydrogen sub-plants. The results of parametric studies show that increasing solar irradiance and molten-salt temperatures have positive effects on system performance. In addition, improvement on electrolyzer efficiency makes hydrogen production more and decreases electricity consumption of the unit. The study implies that solar tower plants are useful for electricity production by high temperatures and also waste heat of each unit enables multiple production.
{"title":"Design and thermodynamic analysis of a solar power plant for hydrogen generation with other beneficial outputs for a residential society","authors":"Yunus Emre Yuksel , Fatih Yilmaz , Murat Ozturk","doi":"10.1016/j.ijhydene.2026.153940","DOIUrl":"10.1016/j.ijhydene.2026.153940","url":null,"abstract":"<div><div>In this study, a comprehensive thermodynamic analysis of an integrated solar tower-based multigeneration system planned for the purpose of electricity, hydrogen, heating, cooling and freshwater production. The design of the system consists of a solar tower receiver with Rankine and Organic Rankine power cycles, a hydrogen production and storage unit, an absorption refrigeration system and a freshwater production plant. In the analysis part of the study, a detailed thermodynamic analysis is performed and to see the effects of basic design parameters such as reference temperature, solar irradiance, molten-salt temperature and electrolyzer efficiency, parametric analyses were calculated. For the basic design parameters, the overall energetic and exergetic efficiencies were found to be 55.29% and 51.18%. The overall exergy destruction rate of the system was calculated as 12.3 MW, mainly occurred in Rankine and hydrogen sub-plants. The results of parametric studies show that increasing solar irradiance and molten-salt temperatures have positive effects on system performance. In addition, improvement on electrolyzer efficiency makes hydrogen production more and decreases electricity consumption of the unit. The study implies that solar tower plants are useful for electricity production by high temperatures and also waste heat of each unit enables multiple production.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153940"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-11Epub Date: 2026-02-09DOI: 10.1016/j.ijhydene.2026.153883
Yuxing Zhang, Dong Yang, Lei Wang, Zhiqin Kang, Yongjun Yu
Carbon monoxide (CO), as an inevitable byproduct in the in-situ supercritical water–coal gasification process coupled with oxygen injection for temperature elevation and hydrogen production, becomes a critical component that must be suppressed and converted due to its low calorific value and toxicity. Based on a self-developed in-situ supercritical water-coal gasification cyclic continuous reaction system, cyclic continuous reaction experiments of CO under supercritical water-coal gasification conditions at different temperatures were conducted. In combination with reaction kinetics, the reaction behavior and kinetic characteristics of CO in the in-situ supercritical water-coal gasification system were systematically analyzed. The main research findings are as follows: Firstly, 450 °C is the threshold temperature that triggers the rapid consumption of CO and promotes the formation of H2, CO2, and CH4 through the water-gas shift reaction and other related reactions. With increasing temperature, CO consumption increasingly favors the formation of H2. Secondly, the rates of the water-gas shift reaction and the methanation reaction at different supercritical water-coal gasification temperatures directly determine the conversion rate and conversion pathway of CO. Thirdly, the supercritical water-coal gasification environment intrinsically promotes CO consumption and H2 formation, providing an advantageous medium for hydrogen production. Enhancing the forward rate of the water-gas shift reaction is essential not only for accelerating CO consumption but also for elevating H2 concentration, while accelerating the forward methanation reaction is critical for further reducing CO levels. Finally, after CO injection, the steady-state concentration of H2 is essentially unaffected by reaction temperature, whereas higher temperatures favor the overall reaction pathway toward the formation of high-calorific-value gases such as H2 and CH4. This study fills the existing gap regarding the reaction behavior and kinetic characteristics of CO in the in-situ supercritical water-coal gasification system. It provides essential theoretical guidance for effectively suppressing and converting CO, optimizing product composition, and enhancing hydrogenation efficiency within in-situ supercritical water-coal gasification processes.
{"title":"Reaction behavior and kinetic characteristics of carbon monoxide in the in-situ supercritical water - coal gasification system","authors":"Yuxing Zhang, Dong Yang, Lei Wang, Zhiqin Kang, Yongjun Yu","doi":"10.1016/j.ijhydene.2026.153883","DOIUrl":"10.1016/j.ijhydene.2026.153883","url":null,"abstract":"<div><div>Carbon monoxide (CO), as an inevitable byproduct in the in-situ supercritical water–coal gasification process coupled with oxygen injection for temperature elevation and hydrogen production, becomes a critical component that must be suppressed and converted due to its low calorific value and toxicity. Based on a self-developed in-situ supercritical water-coal gasification cyclic continuous reaction system, cyclic continuous reaction experiments of CO under supercritical water-coal gasification conditions at different temperatures were conducted. In combination with reaction kinetics, the reaction behavior and kinetic characteristics of CO in the in-situ supercritical water-coal gasification system were systematically analyzed. The main research findings are as follows: Firstly, 450 °C is the threshold temperature that triggers the rapid consumption of CO and promotes the formation of H<sub>2</sub>, CO<sub>2</sub>, and CH<sub>4</sub> through the water-gas shift reaction and other related reactions. With increasing temperature, CO consumption increasingly favors the formation of H<sub>2</sub>. Secondly, the rates of the water-gas shift reaction and the methanation reaction at different supercritical water-coal gasification temperatures directly determine the conversion rate and conversion pathway of CO. Thirdly, the supercritical water-coal gasification environment intrinsically promotes CO consumption and H<sub>2</sub> formation, providing an advantageous medium for hydrogen production. Enhancing the forward rate of the water-gas shift reaction is essential not only for accelerating CO consumption but also for elevating H<sub>2</sub> concentration, while accelerating the forward methanation reaction is critical for further reducing CO levels. Finally, after CO injection, the steady-state concentration of H<sub>2</sub> is essentially unaffected by reaction temperature, whereas higher temperatures favor the overall reaction pathway toward the formation of high-calorific-value gases such as H<sub>2</sub> and CH<sub>4</sub>. This study fills the existing gap regarding the reaction behavior and kinetic characteristics of CO in the in-situ supercritical water-coal gasification system. It provides essential theoretical guidance for effectively suppressing and converting CO, optimizing product composition, and enhancing hydrogenation efficiency within in-situ supercritical water-coal gasification processes.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153883"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-11Epub Date: 2026-02-17DOI: 10.1016/j.ijhydene.2026.153860
Tatyana V. Drabkova , Alexander L. Gusev , Sadritdin M. Turabdzhanov
The development of sustainable water treatment systems is essential for green hydrogen production, as it must meet stringent quality standards for electrolyzers while addressing water scarcity. The study presents an energy-self-sufficient ion-exchange unit (IOU–4F) that converts highly mineralized industrial wastewater into a suitable resource for electrolysis.
The unit consists of a compact modular structure with four conical columns filled with ampholytic sorbent. It achieves selective removal of metal cations and salt anions in a single stage, yielding water with low electrical conductivity suitable for alkaline electrolyzers (AEL) and as pre-treatment for proton exchange membrane (PEM) systems. Regeneration relies on gravity-fed reagents, eliminating electricity needs, while a photovoltaic subsystem ensures operational autonomy.
Pilot tests confirmed purification efficiency exceeding 99%. After multiple cycles, the sorbent retained high exchange capacity and mechanical strength without generating toxic waste.
This technology demonstrates feasibility for off-grid hydrogen production in water-scarce regions, reduces operational costs, promotes water reuse, and supports import independence through local materials. It provides a basis for scalable, decentralized green hydrogen clusters, contributing to energy and water security.
{"title":"Energy-self-sufficient ion-exchange system for pre-electrolysis water treatment in green hydrogen production","authors":"Tatyana V. Drabkova , Alexander L. Gusev , Sadritdin M. Turabdzhanov","doi":"10.1016/j.ijhydene.2026.153860","DOIUrl":"10.1016/j.ijhydene.2026.153860","url":null,"abstract":"<div><div>The development of sustainable water treatment systems is essential for green hydrogen production, as it must meet stringent quality standards for electrolyzers while addressing water scarcity. The study presents an energy-self-sufficient ion-exchange unit (IOU–4F) that converts highly mineralized industrial wastewater into a suitable resource for electrolysis.</div><div>The unit consists of a compact modular structure with four conical columns filled with ampholytic sorbent. It achieves selective removal of metal cations and salt anions in a single stage, yielding water with low electrical conductivity suitable for alkaline electrolyzers (AEL) and as pre-treatment for proton exchange membrane (PEM) systems. Regeneration relies on gravity-fed reagents, eliminating electricity needs, while a photovoltaic subsystem ensures operational autonomy.</div><div>Pilot tests confirmed purification efficiency exceeding 99%. After multiple cycles, the sorbent retained high exchange capacity and mechanical strength without generating toxic waste.</div><div>This technology demonstrates feasibility for off-grid hydrogen production in water-scarce regions, reduces operational costs, promotes water reuse, and supports import independence through local materials. It provides a basis for scalable, decentralized green hydrogen clusters, contributing to energy and water security.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153860"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147424298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper presents a comprehensive real-time simulation framework for hybrid hydrogen–battery trains, integrating detailed subsystem modelling, degradation assessment, and energy management design. A dynamic fuel cells/battery powertrain model is developed in Matlab/Simulink and implemented on a Speedgoat® real-time platform, enabling realistic performance evaluation and hardware-in-the-loop applications. An inverse simulation approach is adopted to analyze energy management strategies and their impact on power allocation, energy consumption, and component degradation. Two alternative energy management systems are investigated and compared through a real-world case study on a long 177.5 km non-electrified railway route in Southern Italy. Although the two strategies exhibit comparable total energy-related operating costs, they result in markedly different degradation patterns and lifecycle cost structures. A conservative fuel cell management strategy reduces fuel cell degradation and lowers the number of required replacements over a 20-year operational horizon by more than a factor of three, despite a 12% increase in hydrogen consumption. This translates into a net reduction of approximately 0.6 M€ in total lifecycle costs (9.19 M€ vs 9.76 M€), while differences in refuelling and recharging expenditures remain marginal. However, a sensitivity analysis identifies the hydrogen price as the dominant external risk, with a ±30% fluctuation impacting the total cost by approximately ±2.0 M€. Degradation-aware energy management emerges as a key design criterion for improving the long-term economic performance and reliability of hybrid railway systems. The proposed real-time simulation framework provides a robust tool to support control design, system validation, and cost-informed decision-making in next-generation sustainable rail transport.
{"title":"Hybrid hydrogen – battery fueled trains: A real-time simulation approach","authors":"Adriano Pozzessere , Uways Mithoowani , Alessandro Ruvio , Giuliano Agati , Gabriele Guglielmo Gagliardi , Paolo Venturini , Domenico Borello","doi":"10.1016/j.ijhydene.2026.153737","DOIUrl":"10.1016/j.ijhydene.2026.153737","url":null,"abstract":"<div><div>The paper presents a comprehensive real-time simulation framework for hybrid hydrogen–battery trains, integrating detailed subsystem modelling, degradation assessment, and energy management design. A dynamic fuel cells/battery powertrain model is developed in Matlab/Simulink and implemented on a Speedgoat® real-time platform, enabling realistic performance evaluation and hardware-in-the-loop applications. An inverse simulation approach is adopted to analyze energy management strategies and their impact on power allocation, energy consumption, and component degradation. Two alternative energy management systems are investigated and compared through a real-world case study on a long 177.5 km non-electrified railway route in Southern Italy. Although the two strategies exhibit comparable total energy-related operating costs, they result in markedly different degradation patterns and lifecycle cost structures. A conservative fuel cell management strategy reduces fuel cell degradation and lowers the number of required replacements over a 20-year operational horizon by more than a factor of three, despite a 12% increase in hydrogen consumption. This translates into a net reduction of approximately 0.6 M€ in total lifecycle costs (9.19 M€ vs 9.76 M€), while differences in refuelling and recharging expenditures remain marginal. However, a sensitivity analysis identifies the hydrogen price as the dominant external risk, with a ±30% fluctuation impacting the total cost by approximately ±2.0 M€. Degradation-aware energy management emerges as a key design criterion for improving the long-term economic performance and reliability of hybrid railway systems. The proposed real-time simulation framework provides a robust tool to support control design, system validation, and cost-informed decision-making in next-generation sustainable rail transport.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153737"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-11Epub Date: 2026-02-10DOI: 10.1016/j.ijhydene.2026.153871
Linsen Li , Zhuwei Yang , Tianli Zhang , Jiale Dou , Ming Ma , Lixia Ling , Li Lin , Zhao Jiang
N-ethylcarbazole/Dodecahydro-N-ethylcarbazole (NECZ/12H-NECZ) has emerged as a highly promising candidate among liquid organic hydrogen carriers (LOHCs), however, the relatively slow dehydrogenation kinetic and low selectivity render the commercial applications. Herein, an accordion-like C3N4 with expanded interlayer spacing and abundant carbon vacancies is synthesized via a mixed-alcohol-assisted bottom-up method. The optimal Pd/EN-C3N4 catalyst (EN-C3N4 denotes accordion-like C3N4 treated by ethanol and n-butanol intercalation) exhibited excellent performance, achieving 99.43% conversion and 5.0 wt% H2 release in 90 min at 453 K. Characterization and DFT calculations reveal that the unique accordion structure provides high specific surface area and abundant carbon vacancies, which improves the dispersion and anchoring stability of Pd NPs. Meawhile, the carbon vacancies increase electron density around Pd nanoparticles and upshift the d-band center, collectively reducing the energy barrier of the rate-determining step. The catalyst also demonstrates excellent stability over 49 h. This work provides a defect-engineering strategy for designing efficient LOHC dehydrogenation catalysts.
n -乙基咔唑/十二氢- n -乙基咔唑(NECZ/12H-NECZ)是有机液体氢载体(lohc)中极具潜力的候选材料,但其脱氢动力学相对较慢,选择性较低,因此无法实现商业化应用。本文采用混合醇辅助自下而上的方法合成了层间距扩大且碳空位丰富的手风琴状C3N4。最佳Pd/EN-C3N4催化剂(EN-C3N4表示经乙醇和正丁醇插层处理的风琴状C3N4)表现出优异的性能,在453k条件下,90 min转化率达到99.43%,H2释放量为5.0 wt%。表征和DFT计算表明,独特的手风琴结构提供了高比表面积和丰富的碳空位,提高了Pd NPs的分散性和锚定稳定性。同时,碳空位增加了钯纳米粒子周围的电子密度,使d带中心上移,共同降低了速率决定步骤的能垒。该催化剂在49 h内也表现出优异的稳定性。这项工作为设计高效LOHC脱氢催化剂提供了缺陷工程策略。
{"title":"Boosting the hydrogen production efficiency of dodecahydro-N-ethylcarbazole by depositing Pd on the accordion-like C3N4","authors":"Linsen Li , Zhuwei Yang , Tianli Zhang , Jiale Dou , Ming Ma , Lixia Ling , Li Lin , Zhao Jiang","doi":"10.1016/j.ijhydene.2026.153871","DOIUrl":"10.1016/j.ijhydene.2026.153871","url":null,"abstract":"<div><div>N-ethylcarbazole/Dodecahydro-N-ethylcarbazole (NECZ/12H-NECZ) has emerged as a highly promising candidate among liquid organic hydrogen carriers (LOHCs), however, the relatively slow dehydrogenation kinetic and low selectivity render the commercial applications. Herein, an accordion-like C<sub>3</sub>N<sub>4</sub> with expanded interlayer spacing and abundant carbon vacancies is synthesized via a mixed-alcohol-assisted bottom-up method. The optimal Pd/EN-C<sub>3</sub>N<sub>4</sub> catalyst (EN-C<sub>3</sub>N<sub>4</sub> denotes accordion-like C<sub>3</sub>N<sub>4</sub> treated by ethanol and n-butanol intercalation) exhibited excellent performance, achieving 99.43% conversion and 5.0 wt% H<sub>2</sub> release in 90 min at 453 K. Characterization and DFT calculations reveal that the unique accordion structure provides high specific surface area and abundant carbon vacancies, which improves the dispersion and anchoring stability of Pd NPs. Meawhile, the carbon vacancies increase electron density around Pd nanoparticles and upshift the d-band center, collectively reducing the energy barrier of the rate-determining step. The catalyst also demonstrates excellent stability over 49 h. This work provides a defect-engineering strategy for designing efficient LOHC dehydrogenation catalysts.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153871"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-11Epub Date: 2026-02-10DOI: 10.1016/j.ijhydene.2026.153904
Lu Liu , Wenyue Wang , Tai Wang , Teng Wang , Xinyu Dong , Tao Zhang
The widespread application of hydrogen liquefaction is constrained by two major challenges: high energy consumption and significant carbon emissions. To address these issues, this study proposes a novel integrated process that combines steam methane reforming (SMR) with the utilization of cold energy from liquefied natural gas (LNG). Unlike the conventional method of sequestering the carbon dioxide produced by SMR as a waste stream, this study innovatively utilizes the captured carbon dioxide as a working fluid in a Brayton cycle for hydrogen precooling. This strategy not only reduces direct carbon dioxide emissions but also lowers overall energy consumption. Furthermore, using carbon dioxide as a refrigerant reduces the demand for LNG cold energy, thereby enhancing heat exchange efficiency. The proposed process was simulated in Aspen HYSYS and optimized using a genetic algorithm to minimize specific energy consumption (SEC). To evaluate its performance, a comprehensive 4E analysis (energy, exergy, economy, and environment) were conducted and compared with two reference processes: one using LNG for carbon sequestration, and the other directly emitting carbon dioxide. For a plant producing 300 tons of liquid hydrogen per day, the proposed process exhibits a competitive specific energy consumption (SEC) of 5.52 kWh/kgLH2 and an exergy efficiency of 54.8%. Compared to the LNG-based carbon sequestration process, due to enhanced temperature compatibility, the SEC of this process is reduced by 7.5%, and the exergy destruction in the precooling stage is reduced by 67.4%. The results indicate that integrating a carbon dioxide Brayton cycle can effectively convert environmental burdens into thermodynamic advantages, providing an economical and sustainable approach for hydrogen liquefaction.
{"title":"Optimization and analysis of a novel hydrogen liquefaction process based on liquefied natural gas cold energy utilization integrating with steam methane reforming","authors":"Lu Liu , Wenyue Wang , Tai Wang , Teng Wang , Xinyu Dong , Tao Zhang","doi":"10.1016/j.ijhydene.2026.153904","DOIUrl":"10.1016/j.ijhydene.2026.153904","url":null,"abstract":"<div><div>The widespread application of hydrogen liquefaction is constrained by two major challenges: high energy consumption and significant carbon emissions. To address these issues, this study proposes a novel integrated process that combines steam methane reforming (SMR) with the utilization of cold energy from liquefied natural gas (LNG). Unlike the conventional method of sequestering the carbon dioxide produced by SMR as a waste stream, this study innovatively utilizes the captured carbon dioxide as a working fluid in a Brayton cycle for hydrogen precooling. This strategy not only reduces direct carbon dioxide emissions but also lowers overall energy consumption. Furthermore, using carbon dioxide as a refrigerant reduces the demand for LNG cold energy, thereby enhancing heat exchange efficiency. The proposed process was simulated in Aspen HYSYS and optimized using a genetic algorithm to minimize specific energy consumption (SEC). To evaluate its performance, a comprehensive 4E analysis (energy, exergy, economy, and environment) were conducted and compared with two reference processes: one using LNG for carbon sequestration, and the other directly emitting carbon dioxide. For a plant producing 300 tons of liquid hydrogen per day, the proposed process exhibits a competitive specific energy consumption (SEC) of 5.52 kWh/kgLH<sub>2</sub> and an exergy efficiency of 54.8%. Compared to the LNG-based carbon sequestration process, due to enhanced temperature compatibility, the SEC of this process is reduced by 7.5%, and the exergy destruction in the precooling stage is reduced by 67.4%. The results indicate that integrating a carbon dioxide Brayton cycle can effectively convert environmental burdens into thermodynamic advantages, providing an economical and sustainable approach for hydrogen liquefaction.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153904"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hydrogen (H2) stands at the forefront of clean energy solutions due to its exceptional gravimetric energy density, environmental friendliness, and widespread availability. However, the development of safe, efficient, and high-capacity H2 storage remains a critical bottleneck for its practical deployment. Due to the cost and safety limitations of conventional methods like liquefaction and high-pressure storage, automotive applications increasingly depend on material-based H2 storage solutions. In this study, a detailed computational investigation of a novel two-dimensional (2D) carbon nitride (C3N2) monolayer (ML) as a promising H2 storage material is performed. The interaction of pristine C3N2 with H2 is weak. This is overcome by enhancing H2 storage performance by functionalizing C3N2 with selected light metal dopants such as Mg, K, and Ca. In this paper, using a first-principles study, we show that C3N2 can accommodate up to four dopants, each exhibiting strong binding energies of −2.93, −2.92, and −4.22 eV/dopant for Mg, K, and Ca, respectively. Bader charge analysis further reveals substantial charge transfer from the dopants to the C3N2 monolayer, effectively transforming the dopants into cations. Thermal stability of metal-doped C3N2 systems is evaluated at 300 K using ab initio molecular dynamics (AIMD) simulations, which confirm robust structural integrity under ambient conditions. Each dopant adsorbs a maximum of five H2 molecules with average adsorption energies within the desired range of −0.15 to −0.60 eV/H2, suitable for ambient temperature operation. We find that 4Mg-, 4K-, and 4Ca-doped C3N2 systems achieve H2 storage capacities of 9.47, 5.96, and 6.57 wt%, respectively, all surpassing the U.S. Department of Energy (DOE) 2025 target of 5.5 wt%. This study establishes metal-doped C3N2 as a promising 2D nanomaterial for next-generation H2 storage and provides valuable design insights for developing practical solid-state H2 carriers.
{"title":"Computational analysis of light metal decorated C3N2 monolayers for efficient hydrogen storage","authors":"Gom Dorji , Sonam Peden , Syed Faraz Hasan , Francois Aguey-Zinsou , Tanveer Hussain","doi":"10.1016/j.ijhydene.2026.153641","DOIUrl":"10.1016/j.ijhydene.2026.153641","url":null,"abstract":"<div><div>Hydrogen (H<sub>2</sub>) stands at the forefront of clean energy solutions due to its exceptional gravimetric energy density, environmental friendliness, and widespread availability. However, the development of safe, efficient, and high-capacity H<sub>2</sub> storage remains a critical bottleneck for its practical deployment. Due to the cost and safety limitations of conventional methods like liquefaction and high-pressure storage, automotive applications increasingly depend on material-based H<sub>2</sub> storage solutions. In this study, a detailed computational investigation of a novel two-dimensional (2D) carbon nitride (C<sub>3</sub>N<sub>2</sub>) monolayer (ML) as a promising H<sub>2</sub> storage material is performed. The interaction of pristine C<sub>3</sub>N<sub>2</sub> with H<sub>2</sub> is weak. This is overcome by enhancing H<sub>2</sub> storage performance by functionalizing C<sub>3</sub>N<sub>2</sub> with selected light metal dopants such as Mg, K, and Ca. In this paper, using a first-principles study, we show that C<sub>3</sub>N<sub>2</sub> can accommodate up to four dopants, each exhibiting strong binding energies of −2.93, −2.92, and −4.22 eV/dopant for Mg, K, and Ca, respectively. Bader charge analysis further reveals substantial charge transfer from the dopants to the C<sub>3</sub>N<sub>2</sub> monolayer, effectively transforming the dopants into cations. Thermal stability of metal-doped C<sub>3</sub>N<sub>2</sub> systems is evaluated at 300 K using ab initio molecular dynamics (AIMD) simulations, which confirm robust structural integrity under ambient conditions. Each dopant adsorbs a maximum of five H<sub>2</sub> molecules with average adsorption energies within the desired range of −0.15 to −0.60 eV/H<sub>2</sub>, suitable for ambient temperature operation. We find that 4Mg-, 4K-, and 4Ca-doped C<sub>3</sub>N<sub>2</sub> systems achieve H<sub>2</sub> storage capacities of 9.47, 5.96, and 6.57 wt%, respectively, all surpassing the U.S. Department of Energy (DOE) 2025 target of 5.5 wt%. This study establishes metal-doped C<sub>3</sub>N<sub>2</sub> as a promising 2D nanomaterial for next-generation H<sub>2</sub> storage and provides valuable design insights for developing practical solid-state H<sub>2</sub> carriers.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153641"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-11Epub Date: 2026-02-09DOI: 10.1016/j.ijhydene.2026.153833
Shuting Jin , Xin Chen , Zhenxing Liang , Chaozhu Shu
Two-dimensional (2D) materials exhibit excellent electrocatalytic hydrogen evolution (HER) activity due to their unique structure, large specific surface area, excellent electrical conductivity, abundant surface functional groups, and superior structure stability. Exploring the structure-performance relationship of 2D materials is essential for the development of efficient and stable electrocatalysts in electrocatalytic HER. In this review, we systematically discuss various types of 2D materials, including graphene, metallocenes, MXenes, transition metal nitrides, transition metal carbides, transition metal phosphides, transition metal sulfides, transition metal borides as well as transition metal oxides, and describe in detail their structure, synthesis and HER performance. In addition, we also deeply analyze the effects of different modification strategies (such as morphology modulation, chemical doping, phase engineering, defect engineering and heterostructure engineering) on the electrocatalytic HER performance of 2D materials, which provides an effective guidance for the rational design of efficient HER catalysts. Furthermore, the advanced characterization techniques for understanding the physicochemical properties of catalysts are introduced, which provide powerful information for the systematic study of electrocatalytic HER performance. Finally, the existing challenges of 2D materials are analyzed in the field of electrocatalytic hydrogen evolution, and insights are presented on the future development of HER electrocatalysts.
{"title":"Hydrogen evolution reaction on two dimensional material-based electrocatalysts: challenges, current status and future perspectives","authors":"Shuting Jin , Xin Chen , Zhenxing Liang , Chaozhu Shu","doi":"10.1016/j.ijhydene.2026.153833","DOIUrl":"10.1016/j.ijhydene.2026.153833","url":null,"abstract":"<div><div>Two-dimensional (2D) materials exhibit excellent electrocatalytic hydrogen evolution (HER) activity due to their unique structure, large specific surface area, excellent electrical conductivity, abundant surface functional groups, and superior structure stability. Exploring the structure-performance relationship of 2D materials is essential for the development of efficient and stable electrocatalysts in electrocatalytic HER. In this review, we systematically discuss various types of 2D materials, including graphene, metallocenes, MXenes, transition metal nitrides, transition metal carbides, transition metal phosphides, transition metal sulfides, transition metal borides as well as transition metal oxides, and describe in detail their structure, synthesis and HER performance. In addition, we also deeply analyze the effects of different modification strategies (such as morphology modulation, chemical doping, phase engineering, defect engineering and heterostructure engineering) on the electrocatalytic HER performance of 2D materials, which provides an effective guidance for the rational design of efficient HER catalysts. Furthermore, the advanced characterization techniques for understanding the physicochemical properties of catalysts are introduced, which provide powerful information for the systematic study of electrocatalytic HER performance. Finally, the existing challenges of 2D materials are analyzed in the field of electrocatalytic hydrogen evolution, and insights are presented on the future development of HER electrocatalysts.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153833"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-11Epub Date: 2026-02-09DOI: 10.1016/j.ijhydene.2026.153953
Yong Guo, Rui Guo
Based on density functional theory, conducted a comprehensive study on the structural, hydrogen storage, electronic, mechanical, lattice dynamical, and thermodynamic properties of the newly designed aluminum-based hydrides AlX3H8 (X = Sc, Ti) to evaluate their potential for hydrogen storage applications. The optimized lattice constants were determined to be 4.666 Å for AlSc3H8 and 4.401 Å for AlTi3H8. Key hydrogen storage performance indicators — gravimetric hydrogen storage capacity and desorption temperature — were found to be 4.56 wt% and 366.81 K for AlSc3H8, and 4.34 wt% and 275.04 K for AlTi3H8, respectively. Negative formation enthalpies indicate thermodynamic stability, and the fulfillment of mechanical stability criteria confirms structural robustness. Electronic structure analysis reveals metallic behavior in both compounds. Furthermore, Pugh's ratio and Poisson's ratio indicate that AlSc3H8 exhibits brittle characteristics, whereas AlTi3H8 demonstrates ductile behavior. Phonon dispersion calculations confirm dynamical stability. These findings collectively suggest that AlSc3H8 and AlTi3H8 are promising candidates for solid-state hydrogen storage applications.
{"title":"First-principles study on the physical properties of aluminum-based hydrides AlX3H8 (X = Sc, Ti) for hydrogen storage","authors":"Yong Guo, Rui Guo","doi":"10.1016/j.ijhydene.2026.153953","DOIUrl":"10.1016/j.ijhydene.2026.153953","url":null,"abstract":"<div><div>Based on density functional theory, conducted a comprehensive study on the structural, hydrogen storage, electronic, mechanical, lattice dynamical, and thermodynamic properties of the newly designed aluminum-based hydrides AlX<sub>3</sub>H<sub>8</sub> (X = Sc, Ti) to evaluate their potential for hydrogen storage applications. The optimized lattice constants were determined to be 4.666 Å for AlSc<sub>3</sub>H<sub>8</sub> and 4.401 Å for AlTi<sub>3</sub>H<sub>8</sub>. Key hydrogen storage performance indicators — gravimetric hydrogen storage capacity and desorption temperature — were found to be 4.56 wt% and 366.81 K for AlSc<sub>3</sub>H<sub>8</sub>, and 4.34 wt% and 275.04 K for AlTi<sub>3</sub>H<sub>8</sub>, respectively. Negative formation enthalpies indicate thermodynamic stability, and the fulfillment of mechanical stability criteria confirms structural robustness. Electronic structure analysis reveals metallic behavior in both compounds. Furthermore, Pugh's ratio and Poisson's ratio indicate that AlSc<sub>3</sub>H<sub>8</sub> exhibits brittle characteristics, whereas AlTi<sub>3</sub>H<sub>8</sub> demonstrates ductile behavior. Phonon dispersion calculations confirm dynamical stability. These findings collectively suggest that AlSc<sub>3</sub>H<sub>8</sub> and AlTi<sub>3</sub>H<sub>8</sub> are promising candidates for solid-state hydrogen storage applications.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153953"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-11Epub Date: 2026-02-09DOI: 10.1016/j.ijhydene.2026.153911
Shi Feng Zai , Zhi Yuan Li , Sen Mao Han, Xin Yu Liu, Yu Han Wu
Designing low−cost and high−efficiency electrocatalysts for hydrogen evolution reaction (HER) is critical for advancing sustainable energy conversion, yet remains challenging in alkaline media because water dissociation and hydrogen adsorption require inherently conflicting surface properties. Herein, density functional theory (DFT) calculations guide the design of a crystalline/amorphous NiSe2/Ni(OH)2 heterostructure, revealing the strong interfacial coupling between crystalline NiSe2 and amorphous Ni(OH)2 modulates the local electronic environment, optimizes intermediates binding energies, and facilitates H2O dissociation. Based on these theoretical findings, we experimentally fabricated a crystalline/amorphous NiSe2/Ni(OH)2 hybrid through a combination of electrochemical deposition and solvothermal selenization, where comprehensive characterizations confirm that crystalline NiSe2 offers abundant reaction sites and facilitates interfacial charge transfer, while its coupling with amorphous Ni(OH)2 enhances active site exposure, jointly boosting the catalytic performance. Benefiting from these features, the crystalline/amorphous hybrid exhibits excellent alkaline HER activities with a low overpotential of 53 mV to drive a current density of 10 mA cm−2, excellent mass transport ability, and superior durability without notable degradation over 100 h electrolysis, outperforming almost all reported oxide/selenide−based catalysts.
设计低成本和高效的析氢反应电催化剂对于推进可持续的能量转化至关重要,但在碱性介质中仍然具有挑战性,因为水解离和氢吸附需要固有的相互冲突的表面性质。本文通过密度泛函理论(DFT)计算指导了晶体/非晶态nis2 /Ni(OH)2异质结构的设计,揭示了晶体nis2与非晶态Ni(OH)2之间的强界面耦合调节了局部电子环境,优化了中间体结合能,促进了H2O的解离。基于这些理论发现,我们通过电化学沉积和溶剂热硒化相结合的方法制备了结晶/非晶态nis2 /Ni(OH)2杂化物,综合表征证实了结晶nis2提供了丰富的反应位点,有利于界面电荷转移,同时与非晶态Ni(OH)2的偶联增强了活性位点的暴露,共同提高了催化性能。得益于这些特性,晶体/非晶杂化物表现出优异的碱性HER活性,过电位低至53 mV,可驱动电流密度为10 mA cm - 2,具有优异的质量传递能力,并且在电解100小时后不会出现明显的降解,优于几乎所有报道的氧化物/硒化物基催化剂。
{"title":"Interfacial electronic structure modulation in crystalline/amorphous NiSe2/Ni(OH)2 heterostructure for efficient alkaline HER","authors":"Shi Feng Zai , Zhi Yuan Li , Sen Mao Han, Xin Yu Liu, Yu Han Wu","doi":"10.1016/j.ijhydene.2026.153911","DOIUrl":"10.1016/j.ijhydene.2026.153911","url":null,"abstract":"<div><div>Designing low−cost and high−efficiency electrocatalysts for hydrogen evolution reaction (HER) is critical for advancing sustainable energy conversion, yet remains challenging in alkaline media because water dissociation and hydrogen adsorption require inherently conflicting surface properties. Herein, density functional theory (DFT) calculations guide the design of a crystalline/amorphous NiSe<sub>2</sub>/Ni(OH)<sub>2</sub> heterostructure, revealing the strong interfacial coupling between crystalline NiSe<sub>2</sub> and amorphous Ni(OH)<sub>2</sub> modulates the local electronic environment, optimizes intermediates binding energies, and facilitates H<sub>2</sub>O dissociation. Based on these theoretical findings, we experimentally fabricated a crystalline/amorphous NiSe<sub>2</sub>/Ni(OH)<sub>2</sub> hybrid through a combination of electrochemical deposition and solvothermal selenization, where comprehensive characterizations confirm that crystalline NiSe<sub>2</sub> offers abundant reaction sites and facilitates interfacial charge transfer, while its coupling with amorphous Ni(OH)<sub>2</sub> enhances active site exposure, jointly boosting the catalytic performance. Benefiting from these features, the crystalline/amorphous hybrid exhibits excellent alkaline HER activities with a low overpotential of 53 mV to drive a current density of 10 mA cm<sup>−2</sup>, excellent mass transport ability, and superior durability without notable degradation over 100 h electrolysis, outperforming almost all reported oxide/selenide−based catalysts.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"216 ","pages":"Article 153911"},"PeriodicalIF":8.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}