Pub Date : 2026-02-04DOI: 10.1016/j.ijhydene.2026.153834
Haobin Hu , Xiuxiang Zhao , Yufeng Wang , Zhenyu Cheng , Chao Kong , Qihong Lei , Enzhou Liu
Photocatalytic hydrogen (H2) production as a representative of clean energy technologies, plays a crucial role in promoting green development. In this study, CuSxSe1-x catalysts with various S:Se ratios were synthesized through a photoinduced self - transformation approach, and CuSxSe1-x/g-C3N4 composite with different CuSxSe1-x content was fabricated via the solvent evaporation method. The investigations show that CuSxSe1-x nanoparticles with an average size of approximately 10 nm are uniformly anchored on the g-C3N4 surface, it can introduce more active sites and expand the light absorption range of the composite. Under irradiation with a 300 W Xe lamp, when the molar ratio of S:Se is 0.5:0.5, the 20 wt% CuS0.5Se0.5/g-C3N4 composite achieves a H2 evolution rate () of 1327.3 μmol∙g−1∙h−1, which is 12.5 times higher than that of pure g-C3N4 (106 μmol∙g−1∙h−1). This can be mainly attributed to the formation of an S-scheme heterojunction between CuS0.5Se0.5 and g-C3N4, which can optimize the electron migration pathway and reduce the overpotential for H2 evolution, ultimately achieving efficient H2 evolution.
{"title":"Efficient photocatalytic H2 evolution over sulfoselenide CuS0.5Se0.5/g-C3N4 S-scheme heterojunction","authors":"Haobin Hu , Xiuxiang Zhao , Yufeng Wang , Zhenyu Cheng , Chao Kong , Qihong Lei , Enzhou Liu","doi":"10.1016/j.ijhydene.2026.153834","DOIUrl":"10.1016/j.ijhydene.2026.153834","url":null,"abstract":"<div><div>Photocatalytic hydrogen (H<sub>2</sub>) production as a representative of clean energy technologies, plays a crucial role in promoting green development. In this study, CuS<sub><em>x</em></sub>Se<sub>1-<em>x</em></sub> catalysts with various S:Se ratios were synthesized through a photoinduced self - transformation approach, and CuS<sub><em>x</em></sub>Se<sub>1-<em>x</em></sub>/g-C<sub>3</sub>N<sub>4</sub> composite with different CuS<sub><em>x</em></sub>Se<sub>1-<em>x</em></sub> content was fabricated via the solvent evaporation method. The investigations show that CuS<sub><em>x</em></sub>Se<sub>1-<em>x</em></sub> nanoparticles with an average size of approximately 10 nm are uniformly anchored on the g-C<sub>3</sub>N<sub>4</sub> surface, it can introduce more active sites and expand the light absorption range of the composite. Under irradiation with a 300 W Xe lamp, when the molar ratio of S:Se is 0.5:0.5, the 20 <em>wt</em>% CuS<sub>0.5</sub>Se<sub>0.5</sub>/g-C<sub>3</sub>N<sub>4</sub> composite achieves a H<sub>2</sub> evolution rate (<span><math><mrow><msub><mi>r</mi><msub><mi>H</mi><mn>2</mn></msub></msub></mrow></math></span>) of 1327.3 μmol∙g<sup>−1</sup>∙h<sup>−1</sup>, which is 12.5 times higher than that of pure g-C<sub>3</sub>N<sub>4</sub> (106 μmol∙g<sup>−1</sup>∙h<sup>−1</sup>). This can be mainly attributed to the formation of an S-scheme heterojunction between CuS<sub>0.5</sub>Se<sub>0.5</sub> and g-C<sub>3</sub>N<sub>4</sub>, which can optimize the electron migration pathway and reduce the overpotential for H<sub>2</sub> evolution, ultimately achieving efficient H<sub>2</sub> evolution.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153834"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102642","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 : 2026-02-04DOI: 10.1016/j.ijhydene.2026.153774
Yichen Gan , Akihiro Ueda , Unggi Yoon , Byoungjik Park , Yangkyun Kim , Wookyung Kim
This study experimentally investigates vented explosions in a scaled model of an underground hydrogen refueling station. The apparatus comprises a 1-L chamber representing the underground storage area, connected to a vertical tower that simulates the passage to the ground surface. A vent at the chamber to tower interface was configured for high static activation pressures to simulate worst-case scenarios. Schlieren imaging captured flame propagation, while the effects of equivalence ratio , vent area , and tower floor area on peak pressures were quantified at the chamber and at the tower top. Results show that strongly influences flame speed and thereby controls the peaks. Changing markedly alters internal peaks but only weakly influences tower-top peaks because of the external explosion. A near-linear correlation between the two peaks is observed across conditions, suggesting a simple regression-based estimator for tower-top loads in similar geometries under high .
{"title":"Experimental study of vented hydrogen-air deflagrations in an underground hydrogen refueling station","authors":"Yichen Gan , Akihiro Ueda , Unggi Yoon , Byoungjik Park , Yangkyun Kim , Wookyung Kim","doi":"10.1016/j.ijhydene.2026.153774","DOIUrl":"10.1016/j.ijhydene.2026.153774","url":null,"abstract":"<div><div>This study experimentally investigates vented explosions in a scaled model of an underground hydrogen refueling station. The apparatus comprises a 1-L chamber representing the underground storage area, connected to a vertical tower that simulates the passage to the ground surface. A vent at the chamber to tower interface was configured for high static activation pressures <span><math><mrow><msub><mi>P</mi><mtext>stat</mtext></msub></mrow></math></span> to simulate worst-case scenarios. Schlieren imaging captured flame propagation, while the effects of equivalence ratio <span><math><mrow><mi>ϕ</mi></mrow></math></span>, vent area <span><math><mrow><msub><mi>A</mi><mi>v</mi></msub></mrow></math></span>, and tower floor area <span><math><mrow><msub><mi>A</mi><mi>f</mi></msub></mrow></math></span> on peak pressures were quantified at the chamber and at the tower top. Results show that <span><math><mrow><mi>ϕ</mi></mrow></math></span> strongly influences flame speed and thereby controls the peaks. Changing <span><math><mrow><msub><mi>A</mi><mi>v</mi></msub></mrow></math></span> markedly alters internal peaks but only weakly influences tower-top peaks because of the external explosion. A near-linear correlation between the two peaks is observed across conditions, suggesting a simple regression-based estimator for tower-top loads in similar geometries under high <span><math><mrow><msub><mi>P</mi><mtext>stat</mtext></msub></mrow></math></span>.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153774"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102639","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 : 2026-02-04DOI: 10.1016/j.ijhydene.2026.153817
Mustafa Kaan Baltacioglu , Onur Bulut
Hydrogen is emerging as one of the most critical energy carriers of the present and near future, and its sustainable utilization relies on environmentally friendly production methods. Water electrolysis is a widely used approach, enabling the decomposition of water into hydrogen and oxygen gases via electrical energy. The hydroxy (HHO) dry cell is a system based on water electrolysis principles, whose performance depends on several parameters, with the composition of the electrolyte being among the most influential. In this study, the effects of adding nanomaterials - specifically multi-walled carbon nanotubes (MWCNTs) and graphene - to the electrolyte on system-level HHO production, energy consumption, and cost were investigated. The results indicate that incorporating MWCNTs improved HHO production by approximately 121% under low current conditions, demonstrating the potential of nanomaterial-enhanced electrolytes for practical performance improvements in HHO dry cells. This study focuses on operational performance rather than detailed electrochemical mechanisms, providing insights relevant for engineering applications.
{"title":"Analysis of innovative electrolyte additives for hydroxy dry cells","authors":"Mustafa Kaan Baltacioglu , Onur Bulut","doi":"10.1016/j.ijhydene.2026.153817","DOIUrl":"10.1016/j.ijhydene.2026.153817","url":null,"abstract":"<div><div>Hydrogen is emerging as one of the most critical energy carriers of the present and near future, and its sustainable utilization relies on environmentally friendly production methods. Water electrolysis is a widely used approach, enabling the decomposition of water into hydrogen and oxygen gases via electrical energy. The hydroxy (HHO) dry cell is a system based on water electrolysis principles, whose performance depends on several parameters, with the composition of the electrolyte being among the most influential. In this study, the effects of adding nanomaterials - specifically multi-walled carbon nanotubes (MWCNTs) and graphene - to the electrolyte on system-level HHO production, energy consumption, and cost were investigated. The results indicate that incorporating MWCNTs improved HHO production by approximately 121% under low current conditions, demonstrating the potential of nanomaterial-enhanced electrolytes for practical performance improvements in HHO dry cells. This study focuses on operational performance rather than detailed electrochemical mechanisms, providing insights relevant for engineering applications.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153817"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102645","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 : 2026-02-04DOI: 10.1016/j.ijhydene.2026.153801
Qingyuan Hu, Yuhao Zong, Kaiming Liu, Wu Wang
A high surface area carbon material was synthesized through a combined mechanical and chemical activation process. The method involved ball-milling a phenolic resin polymer with potassium hydroxide as the chemical activating agent, followed by high-temperature carbonization/activation and subsequent removal of inorganic residues. The specific surface area and porosity of the resulting carbons were systematically influenced by key synthesis parameters, including the KOH/polymer mass ratio, ball-milling duration, and the temperature and holding time of carbonization/activation. The ball-milling step was crucial for achieving a homogeneous mixture of the activator within the precursor. By optimizing these parameters, a super-activated carbon with an exceptionally high specific surface area of nearly 3400 m2/g was successfully prepared. This material demonstrated a significant hydrogen storage capacity, with an excess adsorption of approximately 6.0 wt% at 77 K and 30 bar.
{"title":"Ball-milling assisted synthesis of high surface area carbons from phenolic resin for cryogenic hydrogen storage","authors":"Qingyuan Hu, Yuhao Zong, Kaiming Liu, Wu Wang","doi":"10.1016/j.ijhydene.2026.153801","DOIUrl":"10.1016/j.ijhydene.2026.153801","url":null,"abstract":"<div><div>A high surface area carbon material was synthesized through a combined mechanical and chemical activation process. The method involved ball-milling a phenolic resin polymer with potassium hydroxide as the chemical activating agent, followed by high-temperature carbonization/activation and subsequent removal of inorganic residues. The specific surface area and porosity of the resulting carbons were systematically influenced by key synthesis parameters, including the KOH/polymer mass ratio, ball-milling duration, and the temperature and holding time of carbonization/activation. The ball-milling step was crucial for achieving a homogeneous mixture of the activator within the precursor. By optimizing these parameters, a super-activated carbon with an exceptionally high specific surface area of nearly 3400 m<sup>2</sup>/g was successfully prepared. This material demonstrated a significant hydrogen storage capacity, with an excess adsorption of approximately 6.0 wt% at 77 K and 30 bar.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153801"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102663","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}
This study investigates the coupled effects of hydrogen direct injection and methane port fuel injection in a dual-fuel rotary engine. The optimization of hydrogen injector position, injection angle, and timing is explored, with a focus on the relationship between these parameters and combustion behavior. The entropy-weighted technique for order of preference by similarity to ideal solution method is used for multi-criteria evaluation based on key performance indicators, including indicated mean effective pressure, indicated thermal efficiency, combustion duration, and peak pressure. Results show that the configuration with the hydrogen injector at the chamber mid-section yields the best performance, improving ITE and IMEP by 11.7% and 11.6%, respectively. A vertical injection angle (0°) enhances turbulence near the spark plug, while an intermediate hydrogen injection timing of 170°EA BTDC offers the optimal balance between mixture stratification and combustion phasing.
{"title":"Optimizing hydrogen injection parameters for enhanced combustion in hydrogen-methane rotary engines","authors":"Da Zhang, Ying Wang, Manyao Xie, Xiaopeng Cheng, Xinyu Mu, Yanbo Qiu","doi":"10.1016/j.ijhydene.2026.153813","DOIUrl":"10.1016/j.ijhydene.2026.153813","url":null,"abstract":"<div><div>This study investigates the coupled effects of hydrogen direct injection and methane port fuel injection in a dual-fuel rotary engine. The optimization of hydrogen injector position, injection angle, and timing is explored, with a focus on the relationship between these parameters and combustion behavior. The entropy-weighted technique for order of preference by similarity to ideal solution method is used for multi-criteria evaluation based on key performance indicators, including indicated mean effective pressure, indicated thermal efficiency, combustion duration, and peak pressure. Results show that the configuration with the hydrogen injector at the chamber mid-section yields the best performance, improving ITE and IMEP by 11.7% and 11.6%, respectively. A vertical injection angle (0°) enhances turbulence near the spark plug, while an intermediate hydrogen injection timing of 170°EA BTDC offers the optimal balance between mixture stratification and combustion phasing.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153813"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102640","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 : 2026-02-04DOI: 10.1016/j.ijhydene.2026.153799
Tarık Bercan Sarı , Selmi Erim Bozbag , Deniz Şanlı Yıldız , Can Erkey
Hydrogen internal combustion engines (H2-ICEs) are gaining interest as a route to meet Euro 7 emission standards and carbon neutrality goals. However, their exhaust—rich in water vapor, oxygen, and hydrogen—poses challenges for NOx control. This study evaluates the NH3-SCR performance over a Cu/CHA catalyst under H2-ICE-relevant conditions (H2O:1–20 vol%, O2:1–14 vol%, and H2 0/500 ppm, 150–490 °C). NH3-TPD revealed reduced NH3 uptake with increasing water. NH3 oxidation and low-temperature SCR activity declined with higher H2O while high-temperature conversion improved. Above 250 °C, NOx conversion exceeded 99% regardless of water concentration at 60,000 h−1 GHSV. Increasing water concentration from 1 to 20 vol% resulted in lower NO conversion but with less transient NH3 inhibition behavior. H2 co-feed affected high-temperature deNOx efficiency but had minimal impact between 150 and 400 °C. A kinetic model was developed which captured Standard, Fast SCR and NH3 inhibition behavior under a wide range of water concentrations.
{"title":"Investigation of NOX reduction via NH3-SCR in aftertreatment systems for hydrogen internal combustion engines","authors":"Tarık Bercan Sarı , Selmi Erim Bozbag , Deniz Şanlı Yıldız , Can Erkey","doi":"10.1016/j.ijhydene.2026.153799","DOIUrl":"10.1016/j.ijhydene.2026.153799","url":null,"abstract":"<div><div>Hydrogen internal combustion engines (H<sub>2</sub>-ICEs) are gaining interest as a route to meet Euro 7 emission standards and carbon neutrality goals. However, their exhaust—rich in water vapor, oxygen, and hydrogen—poses challenges for NOx control. This study evaluates the NH<sub>3</sub>-SCR performance over a Cu/CHA catalyst under H<sub>2</sub>-ICE-relevant conditions (H<sub>2</sub>O:1–20 vol%, O<sub>2</sub>:1–14 vol%, and H<sub>2</sub> 0/500 ppm, 150–490 °C). NH<sub>3</sub>-TPD revealed reduced NH<sub>3</sub> uptake with increasing water. NH<sub>3</sub> oxidation and low-temperature SCR activity declined with higher H<sub>2</sub>O while high-temperature conversion improved. Above 250 °C, NOx conversion exceeded 99% regardless of water concentration at 60,000 h<sup>−1</sup> GHSV. Increasing water concentration from 1 to 20 vol% resulted in lower NO conversion but with less transient NH<sub>3</sub> inhibition behavior. H<sub>2</sub> co-feed affected high-temperature deNOx efficiency but had minimal impact between 150 and 400 °C. A kinetic model was developed which captured Standard, Fast SCR and NH<sub>3</sub> inhibition behavior under a wide range of water concentrations.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153799"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102643","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 : 2026-02-04DOI: 10.1016/j.ijhydene.2026.153838
Min Ji Shin , Hee-Young Park , Simon MoonGeun Jung , Won Suk Jung
Electrochemical water splitting is an efficient and ecofriendly method for hydrogen production. Although Pt-based catalysts are the most widely used for the hydrogen evolution reaction (HER), their scarcity and high cost limit their applications. Therefore, the development of highly active catalysts based on nonprecious metals is required. In this study, a Mo-doped NiSe catalyst was synthesized on Ni foam (NF) as the Ni source via hydrothermal. The catalyst exhibited a two-dimensional nanoflower structure, and the presence of crystalline NiSe and Ni3Se2 was confirmed. Mo-doped NiSe achieved a current density of −10 mA cm−2 at an overpotential of −148 mV in 1 M KOH, showing superior HER activity to that of NiSe (−194 mV), p-MoSe2 (−314 mV), and NF (−249 mV). Mo doping enhanced the activity by increasing the electrochemically active surface area and tuning the d-band of Ni. Long term stability tests over 6000 potential cycles reveal that the catalyst undergoes surface reconstruction while preserving its crystalline framework during this process. Mo is partially leached and readsorbed as high valent Mo6+, whereas Ni and Se remain largely unchanged. These results demonstrated that Mo-doped NiSe is a promising alkaline HER catalyst with excellent stability.
电化学水分解是一种高效、环保的制氢方法。虽然pt基催化剂在析氢反应（HER）中应用最为广泛，但其稀缺性和高成本限制了其应用。因此，开发基于非贵金属的高活性催化剂是必要的。本研究以泡沫镍（Ni foam， NF）为Ni源，通过水热法合成了掺杂mo的NiSe催化剂。催化剂呈现出二维纳米花结构，并证实了NiSe和Ni3Se2晶体的存在。在1 M KOH中，mo掺杂的NiSe在- 148 mV过电位下获得了−10 mA cm−2的电流密度，其HER活性优于NiSe （- 194 mV）、p-MoSe2 （- 314 mV）和NF （- 249 mV）。Mo掺杂通过增加Ni的电化学活性表面积和调节Ni的d波段来增强活性。超过6000次潜在循环的长期稳定性测试表明，催化剂在此过程中经历了表面重建，同时保留了其晶体框架。Mo被部分浸出并重新吸附为高价Mo6+，而Ni和Se基本保持不变。这些结果表明，掺杂钼的NiSe是一种很有前途的碱性HER催化剂，具有良好的稳定性。
{"title":"Multiphase heterostructured Mo-doped NiSe catalyst with improved activity and stability for the hydrogen evolution reaction in alkaline electrolyte","authors":"Min Ji Shin , Hee-Young Park , Simon MoonGeun Jung , Won Suk Jung","doi":"10.1016/j.ijhydene.2026.153838","DOIUrl":"10.1016/j.ijhydene.2026.153838","url":null,"abstract":"<div><div>Electrochemical water splitting is an efficient and ecofriendly method for hydrogen production. Although Pt-based catalysts are the most widely used for the hydrogen evolution reaction (HER), their scarcity and high cost limit their applications. Therefore, the development of highly active catalysts based on nonprecious metals is required. In this study, a Mo-doped NiSe catalyst was synthesized on Ni foam (NF) as the Ni source via hydrothermal. The catalyst exhibited a two-dimensional nanoflower structure, and the presence of crystalline NiSe and Ni<sub>3</sub>Se<sub>2</sub> was confirmed. Mo-doped NiSe achieved a current density of −10 mA cm<sup>−2</sup> at an overpotential of −148 mV in 1 M KOH, showing superior HER activity to that of NiSe (−194 mV), <em>p</em>-MoSe<sub>2</sub> (−314 mV), and NF (−249 mV). Mo doping enhanced the activity by increasing the electrochemically active surface area and tuning the d-band of Ni. Long term stability tests over 6000 potential cycles reveal that the catalyst undergoes surface reconstruction while preserving its crystalline framework during this process. Mo is partially leached and readsorbed as high valent Mo<sup>6+</sup>, whereas Ni and Se remain largely unchanged. These results demonstrated that Mo-doped NiSe is a promising alkaline HER catalyst with excellent stability.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153838"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102662","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 : 2026-02-04DOI: 10.1016/j.ijhydene.2026.153837
Donghyun Kim , Sangcheol Jang , Wonjong Yu , Suk Won Cha
A rapid in-situ nanodecoration strategy is developed to enhance the durability of nanostructured La0.6Sr0.4CoO3-δ (LSC) cathodes for solid oxide fuel cells. Cu nanoparticles (∼5 nm) are deposited onto nanoporous PLD-grown LSC surfaces via magnetron sputtering and subsequently oxidized to CuxO under 500 °C operating conditions. Initial electrochemical performance, including power density and polarization resistance, remains comparable between decorated and undecorated cells. However, the undecorated cathode exhibits rapid degradation, with resistance increasing from 1.6 to 3.25 Ω cm2 over 23 h. In contrast, the CuxO-decorated cathode stabilizes after an initial conditioning period, maintaining a resistance of 1.75 Ω cm2. The Cu nanoparticles retain their size during oxidation, indicating morphological stability. Constant-voltage operation reveals a >58% enhancement in current density over time for the decorated electrode. Impedance spectroscopy and distribution of relaxation times (DRT) analysis attribute the performance improvement to a marked reduction in charge transfer resistance. These results demonstrate a simple and scalable surface modification approach for improving the longevity and functionality of nanoporous oxide electrodes in electrochemical energy systems.
{"title":"In situ CuxO nanodecoration via rapid sputtering for tailoring surface nanostructure of oxygen electrodes","authors":"Donghyun Kim , Sangcheol Jang , Wonjong Yu , Suk Won Cha","doi":"10.1016/j.ijhydene.2026.153837","DOIUrl":"10.1016/j.ijhydene.2026.153837","url":null,"abstract":"<div><div>A rapid in-situ nanodecoration strategy is developed to enhance the durability of nanostructured La<sub>0</sub>.<sub>6</sub>Sr<sub>0</sub>.<sub>4</sub>CoO<sub>3-</sub>δ (LSC) cathodes for solid oxide fuel cells. Cu nanoparticles (∼5 nm) are deposited onto nanoporous PLD-grown LSC surfaces via magnetron sputtering and subsequently oxidized to Cu<sub>x</sub>O under 500 °C operating conditions. Initial electrochemical performance, including power density and polarization resistance, remains comparable between decorated and undecorated cells. However, the undecorated cathode exhibits rapid degradation, with resistance increasing from 1.6 to 3.25 Ω cm<sup>2</sup> over 23 h. In contrast, the Cu<sub>x</sub>O-decorated cathode stabilizes after an initial conditioning period, maintaining a resistance of 1.75 Ω cm<sup>2</sup>. The Cu nanoparticles retain their size during oxidation, indicating morphological stability. Constant-voltage operation reveals a >58% enhancement in current density over time for the decorated electrode. Impedance spectroscopy and distribution of relaxation times (DRT) analysis attribute the performance improvement to a marked reduction in charge transfer resistance. These results demonstrate a simple and scalable surface modification approach for improving the longevity and functionality of nanoporous oxide electrodes in electrochemical energy systems.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153837"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102638","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 : 2026-02-04DOI: 10.1016/j.ijhydene.2026.153669
Yasin Furkan Gorgulu , Selcuk Ekici , T. Hikmet Karakoc
Two-dimensional computational fluid dynamics simulations were performed at six representative flight levels (FL300, FL318, FL336, FL354, FL372, and FL390) using real engine-derived boundary conditions. The realizable RNG k–ε turbulence model coupled with the Eddy Dissipation Model was employed to resolve turbulence–chemistry interaction and altitude-specific effects on reactive flow, species transport, and emissions. The combustor geometry and mesh were held constant to isolate the impact of atmospheric variations. The realizable RNG k–ε turbulence model and Eddy Dissipation Model were employed to model turbulence–chemistry interactions within the reacting flow field. Results showed that decreasing ambient pressure and temperature with increasing altitude significantly reduce flame temperature, combustion efficiency, and turbulence kinetic energy. At FL390, the maximum flame temperature was approximately 2278 K, which is about 10.3 % lower than the peak value at FL300. Similarly, NO formation was markedly suppressed at higher altitudes, with a ∼37 % reduction in maximum NO mass fraction from FL300 to FL390, attributed to the temperature-dependent Zeldovich mechanism. The analysis also revealed diminished axial velocity and species conversion efficiency with altitude, indicating a weakening of core combustion intensity. These findings demonstrate the sensitivity of hydrogen combustion dynamics to altitude conditions and offer practical insights for the optimization of hydrogen-fueled aviation propulsion systems. The results reveal a clear trade-off between combustion efficiency and nitrogen oxide formation, where lower altitudes favor stronger combustion and higher NO emissions, while higher altitudes inherently suppress NO formation at the expense of reduced combustion intensity.
利用真实发动机导出的边界条件，在六个具有代表性的飞行水平（FL300、FL318、FL336、FL354、FL372和FL390）进行了二维计算流体动力学模拟。采用可实现的RNG k -ε湍流模型和涡动耗散模型，分析了湍流-化学相互作用和高度特异性对反应流、物质输运和排放的影响。燃烧室的几何形状和网格保持不变，以隔离大气变化的影响。采用可实现的RNG k -ε湍流模型和涡流耗散模型对反应流场内的湍流-化学相互作用进行了模拟。结果表明，随着海拔的升高，环境压力和温度的降低，火焰温度、燃烧效率和湍流动能显著降低。在FL390时，火焰的最高温度约为2278 K，比FL300时的峰值低约10.3%。同样，由于温度依赖的Zeldovich机制，NO的形成在高海拔地区明显受到抑制，从FL300到FL390，最大NO质量分数减少了约37%。轴向速度和物质转换效率随海拔的升高而降低，表明堆芯燃烧强度减弱。这些发现证明了氢燃烧动力学对海拔条件的敏感性，并为氢燃料航空推进系统的优化提供了实用的见解。结果表明，燃烧效率和氮氧化物形成之间存在明显的权衡关系，其中海拔较低有利于燃烧更强烈和更高的NO排放，而海拔较高则以降低燃烧强度为代价抑制NO的形成。
{"title":"Altitude-based CFD investigation of hydrogen combustion behavior in a jet engine combustor using real operational data","authors":"Yasin Furkan Gorgulu , Selcuk Ekici , T. Hikmet Karakoc","doi":"10.1016/j.ijhydene.2026.153669","DOIUrl":"10.1016/j.ijhydene.2026.153669","url":null,"abstract":"<div><div>Two-dimensional computational fluid dynamics simulations were performed at six representative flight levels (FL300, FL318, FL336, FL354, FL372, and FL390) using real engine-derived boundary conditions. The realizable RNG k–ε turbulence model coupled with the Eddy Dissipation Model was employed to resolve turbulence–chemistry interaction and altitude-specific effects on reactive flow, species transport, and emissions. The combustor geometry and mesh were held constant to isolate the impact of atmospheric variations. The realizable RNG k–ε turbulence model and Eddy Dissipation Model were employed to model turbulence–chemistry interactions within the reacting flow field. Results showed that decreasing ambient pressure and temperature with increasing altitude significantly reduce flame temperature, combustion efficiency, and turbulence kinetic energy. At FL390, the maximum flame temperature was approximately 2278 K, which is about 10.3 % lower than the peak value at FL300. Similarly, NO formation was markedly suppressed at higher altitudes, with a ∼37 % reduction in maximum NO mass fraction from FL300 to FL390, attributed to the temperature-dependent Zeldovich mechanism. The analysis also revealed diminished axial velocity and species conversion efficiency with altitude, indicating a weakening of core combustion intensity. These findings demonstrate the sensitivity of hydrogen combustion dynamics to altitude conditions and offer practical insights for the optimization of hydrogen-fueled aviation propulsion systems. The results reveal a clear trade-off between combustion efficiency and nitrogen oxide formation, where lower altitudes favor stronger combustion and higher NO emissions, while higher altitudes inherently suppress NO formation at the expense of reduced combustion intensity.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153669"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102644","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}
Poly(heptazine imide) (PHI) exhibits exceptional photocatalytic performance due to its unique structural advantages. However, its effectiveness is limited by a narrow light response range and inefficiencies in charge carrier separation and transfer. Herein, we introduce an innovative approach to synthesize red PHI (RPHIx) with a reduced interlayer distance and a highly in-plane ordered structure by calcining melon-based carbon nitride with KSCN at varying target calcination temperature. The compact interlayer π-π stacking facilitates n→π∗ electronic transition, thereby broadening the range of light absorption and enhancing the separation of photo-induced carriers. The resulting RPHI600 reveals a remarkable photocatalytic H2 evolution reaction (HER) rate that is 85 times higher than that of pristine PHI under 510< λ < 780 nm irradiation. Moreover, the improved in-plane integrity and reduced interlayer distance facilitate the transfer of charge carriers in both horizontal and vertical directions, leading to an HER rate 2.3 times greater than that of PHI under 420< λ < 780 nm illumination. This work offers valuable insights for enhancing the light-harvesting capability and crystallinity of PHI-based photocatalyst.
{"title":"Boosting n→π∗ electronic transition via reducing interlayer stacking distance in red Poly(heptazine imide) towards efficient photocatalytic H2 production","authors":"Zhengliang Zhao, Tingting Zhao, Zehui Jia, Jiaxin Li, Yushi Xie, Jinyu Li, Mingxia Li, Jinlong Dong","doi":"10.1016/j.ijhydene.2026.153828","DOIUrl":"10.1016/j.ijhydene.2026.153828","url":null,"abstract":"<div><div>Poly(heptazine imide) (PHI) exhibits exceptional photocatalytic performance due to its unique structural advantages. However, its effectiveness is limited by a narrow light response range and inefficiencies in charge carrier separation and transfer. Herein, we introduce an innovative approach to synthesize red PHI (RPHIx) with a reduced interlayer distance and a highly in-plane ordered structure by calcining melon-based carbon nitride with KSCN at varying target calcination temperature. The compact interlayer π-π stacking facilitates n→π∗ electronic transition, thereby broadening the range of light absorption and enhancing the separation of photo-induced carriers. The resulting RPHI600 reveals a remarkable photocatalytic H<sub>2</sub> evolution reaction (HER) rate that is 85 times higher than that of pristine PHI under 510< λ < 780 nm irradiation. Moreover, the improved in-plane integrity and reduced interlayer distance facilitate the transfer of charge carriers in both horizontal and vertical directions, leading to an HER rate 2.3 times greater than that of PHI under 420< λ < 780 nm illumination. This work offers valuable insights for enhancing the light-harvesting capability and crystallinity of PHI-based photocatalyst.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"214 ","pages":"Article 153828"},"PeriodicalIF":8.3,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102664","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}
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