Incorporating obstacles into the anode flow channel is an effective strategy for optimizing gas-liquid mass transfer in proton exchange membrane electrolysis cells. This study experimentally investigates the impact of four obstacle layouts on cell performance and anode two-phase flow. The results demonstrate that obstacle distribution critically influences mass transfer. At a flow rate of 24 mL/min, the uniform three-column layout achieves optimal performance, reducing the operating voltage by 5.54 % at 2 A/cm2 compared to the smooth channel baseline. Two-phase flow analysis confirms that this design enhances bubble distribution uniformity and reduces annular flow dimensions. However, the electrolysis performance does not improve monotonically with increasing flow rate, and the obstacles increase flow resistance. Therefore, the optimal obstacle design requires a trade-off between mass transfer enhancement and pressure loss, depending on the specific operating conditions. This work provides experimental evidence and integrated guidance for the design of high-efficiency PEMEC flow fields.
在阳极流道中加入障碍物是优化质子交换膜电解槽气液传质的有效策略。实验研究了四种障碍物布局对电池性能和阳极两相流的影响。结果表明，障碍物分布对传质有重要影响。在24 mL/min的流速下，均匀的三柱布局达到了最佳性能，与平滑通道基线相比，在2 a /cm2时降低了5.54%的工作电压。两相流分析证实，该设计提高了气泡分布均匀性，减小了环空流动尺寸。然而，电解性能并不是随着流量的增加而单调提高，而且障碍物增加了流动阻力。因此，最优障碍设计需要在质量传递增强和压力损失之间进行权衡，这取决于具体的操作条件。该工作为高效PEMEC流场的设计提供了实验依据和综合指导。
{"title":"Experimental investigation of anode flow channel obstacles on PEMEC performance and two-phase flow distribution characteristics","authors":"Weicheng Sun, Zongqi Liu, Yuan Wang, Mingshu Bi, Jingjie Ren","doi":"10.1016/j.ijhydene.2026.153601","DOIUrl":"10.1016/j.ijhydene.2026.153601","url":null,"abstract":"<div><div>Incorporating obstacles into the anode flow channel is an effective strategy for optimizing gas-liquid mass transfer in proton exchange membrane electrolysis cells. This study experimentally investigates the impact of four obstacle layouts on cell performance and anode two-phase flow. The results demonstrate that obstacle distribution critically influences mass transfer. At a flow rate of 24 mL/min, the uniform three-column layout achieves optimal performance, reducing the operating voltage by 5.54 % at 2 A/cm<sup>2</sup> compared to the smooth channel baseline. Two-phase flow analysis confirms that this design enhances bubble distribution uniformity and reduces annular flow dimensions. However, the electrolysis performance does not improve monotonically with increasing flow rate, and the obstacles increase flow resistance. Therefore, the optimal obstacle design requires a trade-off between mass transfer enhancement and pressure loss, depending on the specific operating conditions. This work provides experimental evidence and integrated guidance for the design of high-efficiency PEMEC flow fields.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"212 ","pages":"Article 153601"},"PeriodicalIF":8.3,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077129","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 : 2026-01-29DOI: 10.1016/j.ijhydene.2026.153671
Tao Meng , Hefu Zhang , Daan Cui , Qiang Meng , Zhe Wang , Yulong Ji , Mojie Cheng , Suxia Ma
This study proposes an integrated process that couples a protonic ceramic electrolyzer cell (PCEC) with the methanation reaction, enabling a one-step conversion in which water, after electrolysis, directly participates in methane synthesis. A two-dimensional coupled Thermo–Mass–Chemical–Electrochemical numerical model is developed, incorporating charge transport, mass transport, chemical kinetics, fluid–solid coupling, and heat transfer. The model systematically evaluates the effects of key operating parameters: cell voltage, operating temperature, CO inlet temperature, and CO flow rate — on hydrogen yield, methane yield, and selectivity. The results indicate that under conditions of 873 K, moderately cooled CO, and 30–40 SCCM nitrogen sweep gas, both high current density and methane selectivity can be achieved; whereas excessive operating temperature or excessive nitrogen flow significantly suppresses methane formation due to the enhancement of the reverse water–gas shift (RWGS) reaction. This work provides new insights and approaches for renewable energy utilization, carbon oxide valorization, and green methane synthesis.
{"title":"Modelling and parametric study of an integrated protonic ceramic electrolyzer cell (PCEC) for methane synthesis","authors":"Tao Meng , Hefu Zhang , Daan Cui , Qiang Meng , Zhe Wang , Yulong Ji , Mojie Cheng , Suxia Ma","doi":"10.1016/j.ijhydene.2026.153671","DOIUrl":"10.1016/j.ijhydene.2026.153671","url":null,"abstract":"<div><div>This study proposes an integrated process that couples a protonic ceramic electrolyzer cell (PCEC) with the methanation reaction, enabling a one-step conversion in which water, after electrolysis, directly participates in methane synthesis. A two-dimensional coupled Thermo–Mass–Chemical–Electrochemical numerical model is developed, incorporating charge transport, mass transport, chemical kinetics, fluid–solid coupling, and heat transfer. The model systematically evaluates the effects of key operating parameters: cell voltage, operating temperature, CO inlet temperature, and CO flow rate — on hydrogen yield, methane yield, and selectivity. The results indicate that under conditions of 873 K, moderately cooled CO, and 30–40 SCCM nitrogen sweep gas, both high current density and methane selectivity can be achieved; whereas excessive operating temperature or excessive nitrogen flow significantly suppresses methane formation due to the enhancement of the reverse water–gas shift (RWGS) reaction. This work provides new insights and approaches for renewable energy utilization, carbon oxide valorization, and green methane synthesis.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"212 ","pages":"Article 153671"},"PeriodicalIF":8.3,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077188","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 : 2026-01-28DOI: 10.1016/j.ijhydene.2026.153673
Haotian Yu , Zeming Yuan , Qiang Han , Jiaxin Li , Tao Li
Magnesium-based hydrogen storage materials (MgH2) are promising for solid-state hydrogen storage (7.6 wt% theoretical capacity, abundant resources, high safety) but suffer from high dehydrogenation temperatures (>300 °C) and slow kinetics. Catalytic modification strategies for MgH2 are systematically summarized and compared in this review, encompassing both single-component catalysts (e.g., transition metals, carbon-based materials, metal oxides) and multi-component synergistic systems (e.g., metal-carbon hybrids, high-entropy alloys). The mechanisms by which these strategies address key bottlenecks are elucidated: transition metals like Ni reduce the dissociation energy of Mg–H bonds through 3d-sp orbital hybridization. N-doped carbon nanotubes enhance cycle stability via electronic regulation and nanoconfinement. Metal oxides optimize hydrogen diffusion paths through defect engineering. In multi-component systems, synergistic effects (e.g., dual-channel electron/hydrogen transport in Ni@C core-shell structures, interface stabilization via configurational entropy in high-entropy alloys) lead to breakthrough performance. Optimized systems can lower the initial dehydrogenation temperature to below 150 °C while maintaining a hydrogen storage capacity of over 6.5 wt%. Furthermore, this review bridges experimental advances with theoretical insights from first-principles calculations and machine learning screening. It also addresses persistent challenges and outlines future research directions for practical application. This work provides crucial theoretical and experimental guidance for developing high-efficiency Mg-based hydrogen storage materials. Specifically, it elucidates the priority of core challenges and provides quantitative design criteria for catalysts, laying a foundation for industrial application.
{"title":"Magnesium-based hydrogen storage materials: Design and performance optimization of single-component and multi-component systems review","authors":"Haotian Yu , Zeming Yuan , Qiang Han , Jiaxin Li , Tao Li","doi":"10.1016/j.ijhydene.2026.153673","DOIUrl":"10.1016/j.ijhydene.2026.153673","url":null,"abstract":"<div><div>Magnesium-based hydrogen storage materials (MgH<sub>2</sub>) are promising for solid-state hydrogen storage (7.6 wt% theoretical capacity, abundant resources, high safety) but suffer from high dehydrogenation temperatures (>300 °C) and slow kinetics. Catalytic modification strategies for MgH<sub>2</sub> are systematically summarized and compared in this review, encompassing both single-component catalysts (e.g., transition metals, carbon-based materials, metal oxides) and multi-component synergistic systems (e.g., metal-carbon hybrids, high-entropy alloys). The mechanisms by which these strategies address key bottlenecks are elucidated: transition metals like Ni reduce the dissociation energy of Mg–H bonds through 3d-sp orbital hybridization. N-doped carbon nanotubes enhance cycle stability via electronic regulation and nanoconfinement. Metal oxides optimize hydrogen diffusion paths through defect engineering. In multi-component systems, synergistic effects (e.g., dual-channel electron/hydrogen transport in Ni@C core-shell structures, interface stabilization via configurational entropy in high-entropy alloys) lead to breakthrough performance. Optimized systems can lower the initial dehydrogenation temperature to below 150 °C while maintaining a hydrogen storage capacity of over 6.5 wt%. Furthermore, this review bridges experimental advances with theoretical insights from first-principles calculations and machine learning screening. It also addresses persistent challenges and outlines future research directions for practical application. This work provides crucial theoretical and experimental guidance for developing high-efficiency Mg-based hydrogen storage materials. Specifically, it elucidates the priority of core challenges and provides quantitative design criteria for catalysts, laying a foundation for industrial application.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"211 ","pages":"Article 153673"},"PeriodicalIF":8.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076564","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 : 2026-01-28DOI: 10.1016/j.ijhydene.2026.153665
Mingzhao Wang , Qingzhao Li , Xiaoping Wen , Zhidong Guo , Feixiang Zhong , Xiong Ding
Blending hydrogen into existing natural gas pipelines offers a cost-effective route for hydrogen transportation, yet hydrogen's distinct physicochemical properties and the geometric heterogeneity of industrial piping can alter explosion dynamics and increase the hazard potential. Here, explosion characteristics and pressure responses of methane/hydrogen/air premixed mixtures is investigated in a variable cross-section pipe over a range of equivalence ratio (Φ) and hydrogen volume fraction (). The results show that the membrane rupture time decreases monotonically with increasing , whereas the rupture pressure fails to show a strictly positive correlation with . After membrane rupture, the flame morphology exhibits irregular transitions; the tulip flame becomes increasingly pronounced with rising , and a clear, complete tulip flame is observed only when ≥ 50 %. Furthermore, the propagation process triggers unstable oscillations, with primary instability oscillations displaying regular periodic patterns at Φ = 0.8 and Φ = 1.2. The maximum amplitude of unstable oscillations occurs at the variable cross-section chamber, with the peak oscillation amplitude reaching 101.69 kPa at Φ = 1 and = 30 %. Chemical kinetic analysis based on GRI-Mech 3.0 reveals that the endothermic reaction is consistently dominated by R38, while at Φ = 1.2, the dominant heat release reaction shifts from R10 to R52 as the increases.
{"title":"Flame dynamics and chemical kinetics analysis of premixed methane-hydrogen-air blends in variable cross-section pipes","authors":"Mingzhao Wang , Qingzhao Li , Xiaoping Wen , Zhidong Guo , Feixiang Zhong , Xiong Ding","doi":"10.1016/j.ijhydene.2026.153665","DOIUrl":"10.1016/j.ijhydene.2026.153665","url":null,"abstract":"<div><div>Blending hydrogen into existing natural gas pipelines offers a cost-effective route for hydrogen transportation, yet hydrogen's distinct physicochemical properties and the geometric heterogeneity of industrial piping can alter explosion dynamics and increase the hazard potential. Here, explosion characteristics and pressure responses of methane/hydrogen/air premixed mixtures is investigated in a variable cross-section pipe over a range of equivalence ratio (Φ) and hydrogen volume fraction (<span><math><mrow><msub><mi>α</mi><msub><mi>H</mi><mn>2</mn></msub></msub></mrow></math></span>). The results show that the membrane rupture time decreases monotonically with increasing <span><math><mrow><msub><mi>α</mi><msub><mi>H</mi><mn>2</mn></msub></msub></mrow></math></span>, whereas the rupture pressure fails to show a strictly positive correlation with <span><math><mrow><msub><mi>α</mi><msub><mi>H</mi><mn>2</mn></msub></msub></mrow></math></span>. After membrane rupture, the flame morphology exhibits irregular transitions; the tulip flame becomes increasingly pronounced with rising <span><math><mrow><msub><mi>α</mi><msub><mi>H</mi><mn>2</mn></msub></msub></mrow></math></span>, and a clear, complete tulip flame is observed only when <span><math><mrow><msub><mi>α</mi><msub><mi>H</mi><mn>2</mn></msub></msub></mrow></math></span> ≥ 50 %. Furthermore, the propagation process triggers unstable oscillations, with primary instability oscillations displaying regular periodic patterns at Φ = 0.8 and Φ = 1.2. The maximum amplitude of unstable oscillations occurs at the variable cross-section chamber, with the peak oscillation amplitude reaching 101.69 kPa at Φ = 1 and <span><math><mrow><msub><mi>α</mi><msub><mi>H</mi><mn>2</mn></msub></msub></mrow></math></span> = 30 %. Chemical kinetic analysis based on GRI-Mech 3.0 reveals that the endothermic reaction is consistently dominated by R38, while at Φ = 1.2, the dominant heat release reaction shifts from R10 to R52 as the <span><math><mrow><msub><mi>α</mi><msub><mi>H</mi><mn>2</mn></msub></msub></mrow></math></span> increases.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"211 ","pages":"Article 153665"},"PeriodicalIF":8.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076569","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 : 2026-01-28DOI: 10.1016/j.ijhydene.2026.153744
Xiyuan Liu , Christian Hacker , Shengnian Wang , Yuhua Duan
Developing new metal hydrides is a critical step toward efficient hydrogen storage in carbon-neutral energy systems. However, existing materials databases, such as the Materials Project, contain a limited number of well-characterized hydrides, which constrains the discovery of optimal candidates. This work presents a framework that integrates causal discovery with a lightweight generative machine learning model to generate novel metal hydride candidates that may not exist in current databases. Using a dataset of 450 samples (270 training, 90 validation, and 90 testing), the model generates 1000 candidates. After ranking and filtering, six previously unreported chemical formulas and crystal structures are identified, four of which are validated by density functional theory simulations and show strong potential for future experimental investigation. Overall, the proposed framework provides a scalable and time-efficient approach for expanding hydrogen storage datasets and accelerating materials discovery.
{"title":"A generative machine learning model for designing metal hydrides applied to hydrogen storage","authors":"Xiyuan Liu , Christian Hacker , Shengnian Wang , Yuhua Duan","doi":"10.1016/j.ijhydene.2026.153744","DOIUrl":"10.1016/j.ijhydene.2026.153744","url":null,"abstract":"<div><div>Developing new metal hydrides is a critical step toward efficient hydrogen storage in carbon-neutral energy systems. However, existing materials databases, such as the Materials Project, contain a limited number of well-characterized hydrides, which constrains the discovery of optimal candidates. This work presents a framework that integrates causal discovery with a lightweight generative machine learning model to generate novel metal hydride candidates that may not exist in current databases. Using a dataset of 450 samples (270 training, 90 validation, and 90 testing), the model generates 1000 candidates. After ranking and filtering, six previously unreported chemical formulas and crystal structures are identified, four of which are validated by density functional theory simulations and show strong potential for future experimental investigation. Overall, the proposed framework provides a scalable and time-efficient approach for expanding hydrogen storage datasets and accelerating materials discovery.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"211 ","pages":"Article 153744"},"PeriodicalIF":8.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076572","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 dependence on technology has increased, along with the development and change in living standards, which has led to increased energy demand and emissions. Therefore, researchers have focused on green hydrogen production to meet the energy demand and reduce emissions. The proton exchange membrane (PEM) electrolysis is one of the most promising methods for producing green hydrogen, attracting increasing attention from researchers in academia and industry. This study focuses on the bibliometric and text-mining analyses of PEM electrolyzers to identify general trends and the current state of the literature, thereby guiding researchers in future work. In this regard, a dataset was first generated using keywords and abstracts extracted from the Scopus webpage. Then, bibliometric and text-mining analyses were conducted on the dataset using R Studio and Python modeling. Our results demonstrate that research on PEM electrolyzers has increased significantly over the past few years, along with an expansion in the diversity of research topics within the field. Most studies in the literature have focused on material design and the integration of PEM electrolyzers with alternative energy systems. Furthermore, techno-economic analysis, life cycle assessment, multi-objective optimization, and machine learning are identified as emerging research areas. Overall, this work provides a comprehensive overview of the current state of PEM electrolyzer research and identifies future directions emphasizing advanced materials development, renewable energy integration, and sustainable energy management strategies.
{"title":"Text-mining and bibliometric analyses for proton exchange membrane electrolyzers","authors":"Ayca Firtin , Ayca Yilmaz , Inci Eroglu , Ramazan Yildirim , Damla Eroglu","doi":"10.1016/j.ijhydene.2026.153666","DOIUrl":"10.1016/j.ijhydene.2026.153666","url":null,"abstract":"<div><div>The dependence on technology has increased, along with the development and change in living standards, which has led to increased energy demand and emissions. Therefore, researchers have focused on green hydrogen production to meet the energy demand and reduce emissions. The proton exchange membrane (PEM) electrolysis is one of the most promising methods for producing green hydrogen, attracting increasing attention from researchers in academia and industry. This study focuses on the bibliometric and text-mining analyses of PEM electrolyzers to identify general trends and the current state of the literature, thereby guiding researchers in future work. In this regard, a dataset was first generated using keywords and abstracts extracted from the Scopus webpage. Then, bibliometric and text-mining analyses were conducted on the dataset using R Studio and Python modeling. Our results demonstrate that research on PEM electrolyzers has increased significantly over the past few years, along with an expansion in the diversity of research topics within the field. Most studies in the literature have focused on material design and the integration of PEM electrolyzers with alternative energy systems. Furthermore, techno-economic analysis, life cycle assessment, multi-objective optimization, and machine learning are identified as emerging research areas. Overall, this work provides a comprehensive overview of the current state of PEM electrolyzer research and identifies future directions emphasizing advanced materials development, renewable energy integration, and sustainable energy management strategies.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"211 ","pages":"Article 153666"},"PeriodicalIF":8.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076579","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 : 2026-01-28DOI: 10.1016/j.ijhydene.2026.153698
Bo Li , Qian Wang , Fei Zhong , Yankun Jiang , Rong Han
Dilute combustion enhances engine fuel economy and reduces NOx emissions through lean burn, EGR, or their combination. In this study, dilution rate (RD)—defined as the ratio of total intake mass (fresh air + EGR) to stoichiometric air—is used to quantify dilution intensity. Experiments on a hydrogen/methanol combined-injection SI engine investigate the effects of RD, λ, REGR, and hydrogen injection proportions (HIP). Results show that higher HIP improves combustion performance—especially under high RD and REGR—but increases NOx. Increasing RD enhances thermal efficiency and lowers NOx at the expense of stability. Higher REGR suppresses NOx but deteriorates combustion, particularly at elevated RD. Both higher HIP and lower REGR reduce HC and CO emissions. The optimal condition—10 % HIP, 1.3 RD, 0 % REGR—balances efficiency, stability, and emissions: BTE increases by 5.46 %, while BSFC, COVIMEP, BSNOx, BSHC, and BSCO decrease by 8.47 %, 4.10 %, 0.91 %, 12.84 %, and 77.0 %, respectively.
{"title":"Comparative evaluation of a hydrogen/methanol combined-injection SI engine under dilute combustion conditions using various dilution working fluids","authors":"Bo Li , Qian Wang , Fei Zhong , Yankun Jiang , Rong Han","doi":"10.1016/j.ijhydene.2026.153698","DOIUrl":"10.1016/j.ijhydene.2026.153698","url":null,"abstract":"<div><div>Dilute combustion enhances engine fuel economy and reduces NOx emissions through lean burn, EGR, or their combination. In this study, dilution rate (R<sub>D</sub>)—defined as the ratio of total intake mass (fresh air + EGR) to stoichiometric air—is used to quantify dilution intensity. Experiments on a hydrogen/methanol combined-injection SI engine investigate the effects of R<sub>D</sub>, λ, R<sub>EGR</sub>, and hydrogen injection proportions (HIP). Results show that higher HIP improves combustion performance—especially under high R<sub>D</sub> and R<sub>EGR</sub>—but increases NOx. Increasing R<sub>D</sub> enhances thermal efficiency and lowers NOx at the expense of stability. Higher R<sub>EGR</sub> suppresses NOx but deteriorates combustion, particularly at elevated R<sub>D</sub>. Both higher HIP and lower R<sub>EGR</sub> reduce HC and CO emissions. The optimal condition—10 % HIP, 1.3 R<sub>D</sub>, 0 % R<sub>EGR</sub>—balances efficiency, stability, and emissions: BTE increases by 5.46 %, while BSFC, COV<sub>IMEP</sub>, BSNOx, BSHC, and BSCO decrease by 8.47 %, 4.10 %, 0.91 %, 12.84 %, and 77.0 %, respectively.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"211 ","pages":"Article 153698"},"PeriodicalIF":8.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076616","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 : 2026-01-28DOI: 10.1016/j.ijhydene.2026.153545
Youxing Wei , Jiazhou Sun , Jianfeng Cai , Yueyue Xia , Zerun Lin , Zhongya Xi , Zhimin Lu , Shunchun Yao
Green ammonia and coal co-firing technology can fundamentally reduce CO2 emissions from coal-fired power plants, and its market feasibility has been verified. However, the complex coal/NH3/O2 interaction in NH3/coal co-firing remains unclear. In addition to the widely studied competition between coal and NH3 for O2, the persistent adsorption behavior on coal char surfaces in co-firing systems requires further investigation. This study experimentally investigates the adsorption and kinetic characteristics of NH3/O2 (alone or coexisting) on coal char surfaces and employs density functional theory (DFT) to elucidate the adsorption behavior at the microscopic level. Experimental results show that oxygen-containing functional groups and active carbon sites enhance the adsorption of O2 and NH3. The adsorption capacity for O2 is stronger than that for NH3, primarily driven by chemisorption. Under NH3/O2 coexistence conditions, the oxygen-containing functional groups generated from adsorbed O2 at low concentrations provide additional binding sites for NH3, showing a synergistic effect. At high concentrations, O2 preferentially occupies the key active sites and inhibits NH3 adsorption, dominating the competitive effect. Adsorption kinetics show that models such as Langmuir can effectively predict the NH3/O2 chemisorption characteristics. DFT results show that O2 preferentially adsorbs onto carbonyl sites, which significantly enhances the electron mobility of the char, whereas NH3 tends to bind on carboxylic groups and unsaturated carbon sites, mainly relying on weak interactions. Under co-adsorption conditions, O2 forms an electron accumulation region through strong π-π interactions, while NH3 achieves synergistic adsorption via hydrogen bonding or coordination with carboxyl groups. The synergistic effect enhances the electron interaction strength, but the competitive effect affects the adsorption efficiency and reaction path. This study provides a new basis for the adsorption behavior and synergistic and competitive effects in NH3/coal co-firing.
{"title":"Experimental and DFT study on the NH3/O2 adsorption characteristics and mechanism in NH3/coal co-firing","authors":"Youxing Wei , Jiazhou Sun , Jianfeng Cai , Yueyue Xia , Zerun Lin , Zhongya Xi , Zhimin Lu , Shunchun Yao","doi":"10.1016/j.ijhydene.2026.153545","DOIUrl":"10.1016/j.ijhydene.2026.153545","url":null,"abstract":"<div><div>Green ammonia and coal co-firing technology can fundamentally reduce CO<sub>2</sub> emissions from coal-fired power plants, and its market feasibility has been verified. However, the complex coal/NH<sub>3</sub>/O<sub>2</sub> interaction in NH<sub>3</sub>/coal co-firing remains unclear. In addition to the widely studied competition between coal and NH<sub>3</sub> for O<sub>2</sub>, the persistent adsorption behavior on coal char surfaces in co-firing systems requires further investigation. This study experimentally investigates the adsorption and kinetic characteristics of NH<sub>3</sub>/O<sub>2</sub> (alone or coexisting) on coal char surfaces and employs density functional theory (DFT) to elucidate the adsorption behavior at the microscopic level. Experimental results show that oxygen-containing functional groups and active carbon sites enhance the adsorption of O<sub>2</sub> and NH<sub>3</sub>. The adsorption capacity for O<sub>2</sub> is stronger than that for NH<sub>3</sub>, primarily driven by chemisorption. Under NH<sub>3</sub>/O<sub>2</sub> coexistence conditions, the oxygen-containing functional groups generated from adsorbed O<sub>2</sub> at low concentrations provide additional binding sites for NH<sub>3</sub>, showing a synergistic effect. At high concentrations, O<sub>2</sub> preferentially occupies the key active sites and inhibits NH<sub>3</sub> adsorption, dominating the competitive effect. Adsorption kinetics show that models such as Langmuir can effectively predict the NH<sub>3</sub>/O<sub>2</sub> chemisorption characteristics. DFT results show that O<sub>2</sub> preferentially adsorbs onto carbonyl sites, which significantly enhances the electron mobility of the char, whereas NH<sub>3</sub> tends to bind on carboxylic groups and unsaturated carbon sites, mainly relying on weak interactions. Under co-adsorption conditions, O<sub>2</sub> forms an electron accumulation region through strong π-π interactions, while NH<sub>3</sub> achieves synergistic adsorption via hydrogen bonding or coordination with carboxyl groups. The synergistic effect enhances the electron interaction strength, but the competitive effect affects the adsorption efficiency and reaction path. This study provides a new basis for the adsorption behavior and synergistic and competitive effects in NH<sub>3</sub>/coal co-firing.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"211 ","pages":"Article 153545"},"PeriodicalIF":8.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076580","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 : 2026-01-28DOI: 10.1016/j.ijhydene.2026.153547
Muzamil Ali Brohi , Mingyu Ma , Juan Wu , Jacob Senior Atta Owusu , Dengxin Li , Mazhar Ahmed Memon , Jiahui Li , Xiaochao Zou , Guien Zhou , Wenjing Sang
Catalytic steam gasification is a promising route for converting coal tar, a challenging heavy by-product, into high-value hydrogen-rich syngas. The process allows for the efficient conversion of complex hydrocarbons, yet the search for cost-effective and highly active catalysts to maximize hydrogen yield remains a key research objective. This study investigated the catalytic performance of Ce-doped Ni/ZrO2 catalysts in hydrogen-rich syngas production via steam gasification of coal tar. Initially, a series of Ni/ZrO2 catalysts with varying Ni loadings was synthesized and tested. Among these, the 20Ni/ZrO2 catalyst exhibited the highest hydrogen yield 29.64 mmol g−1, compared to only 20.67 mmol g−1 obtained in the absence of any catalyst, confirming the catalytic contribution of Ni/ZrO2 toward enhanced gasification efficiency. To further improve performance, Ce was incorporated into the optimal Ni/ZrO2 catalyst, forming CexNi1-x/ZrO2 to improve the catalytic performance. The 5Ce5Ni/ZrO2 catalyst demonstrated superior activity, achieving the maximum hydrogen yield of 34.78 mmol g−1, representing a substantial improvement over both the non-catalytic and Ni-only systems. Structural characterizations using XRD, XPS, BET, SEM-EDX, Raman spectroscopy, TGA and TEM, revealed that Ce doping enhanced Ni dispersion, surface area, and redox behavior. These findings confirm that Ce incorporation optimizes the Ni/ZrO2 catalyst structure, enabling more efficient hydrogen-rich syngas production during catalytic steam gasification of coal tar.
{"title":"Enhanced hydrogen production from coal tar over highly dispersed Ce–Ni/ZrO2 catalysts","authors":"Muzamil Ali Brohi , Mingyu Ma , Juan Wu , Jacob Senior Atta Owusu , Dengxin Li , Mazhar Ahmed Memon , Jiahui Li , Xiaochao Zou , Guien Zhou , Wenjing Sang","doi":"10.1016/j.ijhydene.2026.153547","DOIUrl":"10.1016/j.ijhydene.2026.153547","url":null,"abstract":"<div><div>Catalytic steam gasification is a promising route for converting coal tar, a challenging heavy by-product, into high-value hydrogen-rich syngas. The process allows for the efficient conversion of complex hydrocarbons, yet the search for cost-effective and highly active catalysts to maximize hydrogen yield remains a key research objective. This study investigated the catalytic performance of Ce-doped Ni/ZrO<sub>2</sub> catalysts in hydrogen-rich syngas production via steam gasification of coal tar. Initially, a series of Ni/ZrO<sub>2</sub> catalysts with varying Ni loadings was synthesized and tested. Among these, the 20Ni/ZrO<sub>2</sub> catalyst exhibited the highest hydrogen yield 29.64 mmol g<sup>−1</sup>, compared to only 20.67 mmol g<sup>−1</sup> obtained in the absence of any catalyst, confirming the catalytic contribution of Ni/ZrO<sub>2</sub> toward enhanced gasification efficiency. To further improve performance, Ce was incorporated into the optimal Ni/ZrO<sub>2</sub> catalyst, forming Ce<sub>x</sub>Ni<sub>1-x</sub>/ZrO<sub>2</sub> to improve the catalytic performance. The 5Ce5Ni/ZrO<sub>2</sub> catalyst demonstrated superior activity, achieving the maximum hydrogen yield of 34.78 mmol g<sup>−1</sup>, representing a substantial improvement over both the non-catalytic and Ni-only systems. Structural characterizations using XRD, XPS, BET, SEM-EDX, Raman spectroscopy, TGA and TEM, revealed that Ce doping enhanced Ni dispersion, surface area, and redox behavior. These findings confirm that Ce incorporation optimizes the Ni/ZrO<sub>2</sub> catalyst structure, enabling more efficient hydrogen-rich syngas production during catalytic steam gasification of coal tar.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"211 ","pages":"Article 153547"},"PeriodicalIF":8.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076568","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 : 2026-01-28DOI: 10.1016/j.ijhydene.2026.153450
Dawid Kutyła , Michihisa Fukumoto , Hiroki Takahashi , Ryuu Takahashi , Katarzyna Skibińska , Piotr Żabiński
Porous Ni–Pt and Ni–Pt–Ni electrocatalysts were produced by molten-salt aluminium deposition and dissolution, which created continuous porous foams with high internal surface area. Structural analysis confirmed that the simple Ni–Pt bilayer evolves into a Pt-rich surface, and the sandwich Ni–Pt–Ni architecture retains most of the Pt within the porous structure. Catalytic tests reveals differences in HER (Hydrogen Evolution Reaction) and OER (Oxygen Evolution Reaction) kinetics: the Ni–Pt foam reaches −100 mA cm−2 for HER at −102 mV and displays a low Tafel slope of 32.2 mV dec−1, while the Ni–Pt–Ni foam requires −179 mV and shows 42.6 mV dec−1. Both Pt-containing foams also reduce the OER overpotential to ≈+1.69 V at +100 mA cm−2. The results demonstrate that maximising Pt exposure in the interface area is key to tailoring noble-metal performance materials for water splitting applications.
采用熔盐铝沉积和溶解法制备了多孔Ni-Pt和Ni-Pt - ni电催化剂，形成了具有高内表面积的连续多孔泡沫。结构分析证实，简单的Ni-Pt双分子层演变成富Pt表面，夹层结构的Ni-Pt - ni结构保留了多孔结构内的大部分Pt。催化试验揭示了HER（析氢反应）和OER（析氧反应）动力学的差异：Ni-Pt泡沫在- 102 mV下的析氢反应达到- 100 mA cm - 2，显示出32.2 mV dec - 1的低塔费尔斜率，而Ni-Pt - ni泡沫需要- 179 mV，显示出42.6 mV dec - 1。在+100 mA cm−2时，两种含pt泡沫也将OER过电位降低到≈+1.69 V。结果表明，最大化Pt在界面区域的暴露是定制用于水分解应用的贵金属性能材料的关键。
{"title":"Ni–Pt versus Ni–Pt–Ni layered electrodes for water electrolysis obtained by molten-salt Al deposition/dissolution technique","authors":"Dawid Kutyła , Michihisa Fukumoto , Hiroki Takahashi , Ryuu Takahashi , Katarzyna Skibińska , Piotr Żabiński","doi":"10.1016/j.ijhydene.2026.153450","DOIUrl":"10.1016/j.ijhydene.2026.153450","url":null,"abstract":"<div><div>Porous Ni–Pt and Ni–Pt–Ni electrocatalysts were produced by molten-salt aluminium deposition and dissolution, which created continuous porous foams with high internal surface area. Structural analysis confirmed that the simple Ni–Pt bilayer evolves into a Pt-rich surface, and the sandwich Ni–Pt–Ni architecture retains most of the Pt within the porous structure. Catalytic tests reveals differences in HER (Hydrogen Evolution Reaction) and OER (Oxygen Evolution Reaction) kinetics: the Ni–Pt foam reaches −100 mA cm<sup>−2</sup> for HER at −102 mV and displays a low Tafel slope of 32.2 mV dec<sup>−1</sup>, while the Ni–Pt–Ni foam requires −179 mV and shows 42.6 mV dec<sup>−1</sup>. Both Pt-containing foams also reduce the OER overpotential to ≈+1.69 V at +100 mA cm<sup>−2</sup>. The results demonstrate that maximising Pt exposure in the interface area is key to tailoring noble-metal performance materials for water splitting applications.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"211 ","pages":"Article 153450"},"PeriodicalIF":8.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076618","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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