Pub Date : 2024-09-24DOI: 10.1016/j.ijhydene.2024.09.280
ZnS is widely used in the photocatalytic decomposition of water to produce hydrogen due to its fast electron-hole pair generation and high negative potential. However, its absorption in the visible region is poor due to its wide band gap, and it has serious photogenerated carrier recombination problems. Herein, a shallow impurity energy level was introduced by doping the ZnS lattice with Cd. Due to its presence, electrons trying to return to the valence band are trapped and excited twice, suppressing the recombination of photogenerated carriers and greatly improving electron utilization. The Cd1.5-ZnS possesses a hydrogen production rate as high as 85722.20 μmol/g, which is 17 times higher than pure ZnS. Meanwhile, Cd1.5-ZnS has a narrower forbidden band and superior visible light absorption, and the serious photocorrosion problem of ZnS has been suppressed. This study provides a viable approach for the synthesis of photocatalysts with adjustable band gaps and enhanced hydrogen precipitation efficiency.
{"title":"Effect mechanism of Cd on band structure and photocatalytic hydrogen production performance of ZnS","authors":"","doi":"10.1016/j.ijhydene.2024.09.280","DOIUrl":"10.1016/j.ijhydene.2024.09.280","url":null,"abstract":"<div><div>ZnS is widely used in the photocatalytic decomposition of water to produce hydrogen due to its fast electron-hole pair generation and high negative potential. However, its absorption in the visible region is poor due to its wide band gap, and it has serious photogenerated carrier recombination problems. Herein, a shallow impurity energy level was introduced by doping the ZnS lattice with Cd. Due to its presence, electrons trying to return to the valence band are trapped and excited twice, suppressing the recombination of photogenerated carriers and greatly improving electron utilization. The Cd1.5-ZnS possesses a hydrogen production rate as high as 85722.20 μmol/g, which is 17 times higher than pure ZnS. Meanwhile, Cd1.5-ZnS has a narrower forbidden band and superior visible light absorption, and the serious photocorrosion problem of ZnS has been suppressed. This study provides a viable approach for the synthesis of photocatalysts with adjustable band gaps and enhanced hydrogen precipitation efficiency.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314120","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 : 2024-09-24DOI: 10.1016/j.ijhydene.2024.09.143
Supercapacitors have emerged as a highly promising technology for energy storage, offering benefits such as high power output, adjustable energy density, and robust cyclic stability. The performance of these devices is largely influenced by the electrode materials used, which must provide substantial charge storage, excellent rate capability, and strong conductivity. Among various strategies developed to address these challenges, sulfurization has gained notable attention for its effectiveness in enhancing the electrochemical properties of electrode materials. This review article provides an in-depth examination of the sulfurization process applied to electrodes, aiming to deliver a thorough overview of recent advancements, the effects of sulfur integration on electrode characteristics, and the consequent improvements in supercapacitor performance. It delves into how sulfurization affects the morphology, structure, and composition of electrode materials, including changes in surface area, pore size distribution, crystal structure, and the creation of active sites. The review consolidates findings on enhanced specific capacitance, improved rate capability, extended cycle life, and increased energy density achieved through sulfurization. Additionally, it addresses the challenges and limitations of sulfurization, offering insights into potential solutions and future research directions.
{"title":"Unlocking the potential of sulfurized electrode materials for next-generation supercapacitor technology","authors":"","doi":"10.1016/j.ijhydene.2024.09.143","DOIUrl":"10.1016/j.ijhydene.2024.09.143","url":null,"abstract":"<div><div>Supercapacitors have emerged as a highly promising technology for energy storage, offering benefits such as high power output, adjustable energy density, and robust cyclic stability. The performance of these devices is largely influenced by the electrode materials used, which must provide substantial charge storage, excellent rate capability, and strong conductivity. Among various strategies developed to address these challenges, sulfurization has gained notable attention for its effectiveness in enhancing the electrochemical properties of electrode materials. This review article provides an in-depth examination of the sulfurization process applied to electrodes, aiming to deliver a thorough overview of recent advancements, the effects of sulfur integration on electrode characteristics, and the consequent improvements in supercapacitor performance. It delves into how sulfurization affects the morphology, structure, and composition of electrode materials, including changes in surface area, pore size distribution, crystal structure, and the creation of active sites. The review consolidates findings on enhanced specific capacitance, improved rate capability, extended cycle life, and increased energy density achieved through sulfurization. Additionally, it addresses the challenges and limitations of sulfurization, offering insights into potential solutions and future research directions.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314193","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 : 2024-09-24DOI: 10.1016/j.ijhydene.2024.09.275
Limited charge transfer and slow oxygen evolution (OER) kinetics significantly impede the practical realization of photoanodes for photoelectrochemical (PEC) water splitting. Here, pn-type-Fe2O3 homojunction photoanode catalysts with P active sites are designed by doping phosphorus (P) into outer lattice of n-type Fe2O3 nanorods (pn-P-Fe2O3). The optimized pn-P-Fe2O3 photoanode shows the maximum photocurrent density of 2.61 mA/cm2 at 1.23 VRHE, and the value is 6.4 times greater than that of pristine Fe2O3. Experimental and theoretical results clearly show that the P–N homogeneous junctions constructed in Fe2O3 through P-doping increase active sites for H2O adsorption and activation, reduce OER reaction energy barrier, and promote effective separation of photogenerated electron-hole pairs and water splitting kinetics. This not only makes the photoelectric water decomposition performance outstanding, but also produces excellent durability. This work provides a novel simple and environmentally friendly strategy for designing effective photoanodes for PEC water splitting.
有限的电荷转移和缓慢的氧进化（OER）动力学严重阻碍了光电化学（PEC）水分离光阳极的实际应用。在此，通过在 n 型 Fe2O3 纳米棒（pn-P-Fe2O3）的外晶格中掺入磷（P），设计出具有 P 活性位点的 pn 型 Fe2O3 同结光电阳极催化剂。优化后的 pn-P-Fe2O3 光阳极在 1.23 VRHE 下的最大光电流密度为 2.61 mA/cm2，是原始 Fe2O3 的 6.4 倍。实验和理论结果清楚地表明，通过掺杂 P 在 Fe2O3 中构建的 P-N 均相结增加了 H2O 吸附和活化的活性位点，降低了 OER 反应能垒，促进了光生电子-空穴对的有效分离和水分裂动力学。这不仅使光电水分解性能突出，而且还产生了良好的耐久性。这项工作为设计用于 PEC 水分离的有效光阳极提供了一种简单而环保的新策略。
{"title":"P–N homojunction and heteroatom active site engineering over Fe2O3 nanorods for highly efficient photoelectrochemical water splitting","authors":"","doi":"10.1016/j.ijhydene.2024.09.275","DOIUrl":"10.1016/j.ijhydene.2024.09.275","url":null,"abstract":"<div><div>Limited charge transfer and slow oxygen evolution (OER) kinetics significantly impede the practical realization of photoanodes for photoelectrochemical (PEC) water splitting. Here, pn-type-Fe<sub>2</sub>O<sub>3</sub> homojunction photoanode catalysts with P active sites are designed by doping phosphorus (P) into outer lattice of n-type Fe<sub>2</sub>O<sub>3</sub> nanorods (pn-P-Fe<sub>2</sub>O<sub>3</sub>). The optimized pn-P-Fe<sub>2</sub>O<sub>3</sub> photoanode shows the maximum photocurrent density of 2.61 mA/cm<sup>2</sup> at 1.23 V<sub>RHE</sub>, and the value is 6.4 times greater than that of pristine Fe<sub>2</sub>O<sub>3</sub>. Experimental and theoretical results clearly show that the P–N homogeneous junctions constructed in Fe<sub>2</sub>O<sub>3</sub> through P-doping increase active sites for H<sub>2</sub>O adsorption and activation, reduce OER reaction energy barrier, and promote effective separation of photogenerated electron-hole pairs and water splitting kinetics. This not only makes the photoelectric water decomposition performance outstanding, but also produces excellent durability. This work provides a novel simple and environmentally friendly strategy for designing effective photoanodes for PEC water splitting.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314538","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 : 2024-09-24DOI: 10.1016/j.ijhydene.2024.09.285
The operational cabin of hydrogen tube bundle containers (HTBCs) is susceptible to vibration and fatigue loads during transportation, which may result in hydrogen leakage and deflagration accidents. In this paper, a three-dimensional (3D) computational fluid dynamics (CFD) model is developed to simulate the effects of leakage diameter, leakage pressure, leakage direction and position on hydrogen leakage and diffusion in the operational cabin of HTBCs. The results demonstrate that the formation of vortex recirculation zones leads to the accumulation of flammable gas cloud (FGC) in the operational cabin. The medium leakage diameter (1.5 mm) and higher leakage pressure (20 MPa, 35 MPa) cause the operational cabin to be filled with FGC within 5 s, requiring the operational cabin to be designed with no possible ignition source inside. In addition, when hydrogen leaks from the +Z direction, the sensor responds within 0.31 s, which is 1.7 s earlier than the response time in the -Z direction, indicating that the existing sensor layout cannot meet the requirements of fast response. When the leak position (L3) is close to the vent, the FGC volume proportion at 2 s is 19.3 % and 15.88 % lower than that of L1 and L2, respectively, indicating that the leak position close to the vent can effectively slow down the accumulation of FGC. The research results have implications for the safety design of operational cabin of HTBCs, the layout of hydrogen sensors and vents, and the emergency response measures for hydrogen leakage.
{"title":"Hydrogen leakage and diffusion in the operational cabin of hydrogen tube bundle containers：A CFD study","authors":"","doi":"10.1016/j.ijhydene.2024.09.285","DOIUrl":"10.1016/j.ijhydene.2024.09.285","url":null,"abstract":"<div><div>The operational cabin of hydrogen tube bundle containers (HTBCs) is susceptible to vibration and fatigue loads during transportation, which may result in hydrogen leakage and deflagration accidents. In this paper, a three-dimensional (3D) computational fluid dynamics (CFD) model is developed to simulate the effects of leakage diameter, leakage pressure, leakage direction and position on hydrogen leakage and diffusion in the operational cabin of HTBCs. The results demonstrate that the formation of vortex recirculation zones leads to the accumulation of flammable gas cloud (FGC) in the operational cabin. The medium leakage diameter (1.5 mm) and higher leakage pressure (20 MPa, 35 MPa) cause the operational cabin to be filled with FGC within 5 s, requiring the operational cabin to be designed with no possible ignition source inside. In addition, when hydrogen leaks from the +Z direction, the sensor responds within 0.31 s, which is 1.7 s earlier than the response time in the -Z direction, indicating that the existing sensor layout cannot meet the requirements of fast response. When the leak position (L<sub>3</sub>) is close to the vent, the FGC volume proportion at 2 s is 19.3 % and 15.88 % lower than that of L<sub>1</sub> and L<sub>2</sub>, respectively, indicating that the leak position close to the vent can effectively slow down the accumulation of FGC. The research results have implications for the safety design of operational cabin of HTBCs, the layout of hydrogen sensors and vents, and the emergency response measures for hydrogen leakage.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314747","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 : 2024-09-24DOI: 10.1016/j.ijhydene.2024.09.197
Photovoltaic (PV) power generation has issues of volatility and intermittency. Currently, PV plants are generally equipped with 10% rated capacity lithium-ion (Li) battery energy storage systems in China, who often fail to suppress fluctuation in the output power of PV plants effectively and meet the grid-connected standard. The hybrid energy storage system (HESS) combining with hydrogen production and Li battery system can produce hydrogen by water electrolysis during the peak period of PV power generation, effectively improving PV utilization efficiency, while smoothing PV power fluctuation and improving grid connection electricity quality. Firstly, models of the solid oxide electrolysis cell (SOEC) and alkaline electrolysis cell (AEC) systems for hydrogen production, and Li battery energy storage system are established, and the transient response characteristics of each system are analyzed. Secondly, an adaptive wavelet packet decomposition (AWPD) method for PV power signal decomposition is proposed based on the wavelet packet decomposition (WPD) method. Thirdly, a capacity configuration method for HESS are proposed based on the APWD method. Fourthly, a coordinated control strategy for HESS is proposed with the transient response characteristics of different energy storage systems and the state of charge for Li battery system. Finally, the proposed method is validated through simulation experiments based on the actual power data of the PV plant. The results show that the developed methods can effectively utilize partial PV power generation to produce hydrogen, improve PV utilization, and the combined output power of PV plant and HESS can fulfill the grid-connected standard.
{"title":"Coordinated control algorithm of hydrogen production-battery based hybrid energy storage system for suppressing fluctuation of PV power","authors":"","doi":"10.1016/j.ijhydene.2024.09.197","DOIUrl":"10.1016/j.ijhydene.2024.09.197","url":null,"abstract":"<div><div>Photovoltaic (PV) power generation has issues of volatility and intermittency. Currently, PV plants are generally equipped with 10% rated capacity lithium-ion (Li) battery energy storage systems in China, who often fail to suppress fluctuation in the output power of PV plants effectively and meet the grid-connected standard. The hybrid energy storage system (HESS) combining with hydrogen production and Li battery system can produce hydrogen by water electrolysis during the peak period of PV power generation, effectively improving PV utilization efficiency, while smoothing PV power fluctuation and improving grid connection electricity quality. Firstly, models of the solid oxide electrolysis cell (SOEC) and alkaline electrolysis cell (AEC) systems for hydrogen production, and Li battery energy storage system are established, and the transient response characteristics of each system are analyzed. Secondly, an adaptive wavelet packet decomposition (AWPD) method for PV power signal decomposition is proposed based on the wavelet packet decomposition (WPD) method. Thirdly, a capacity configuration method for HESS are proposed based on the APWD method. Fourthly, a coordinated control strategy for HESS is proposed with the transient response characteristics of different energy storage systems and the state of charge for Li battery system. Finally, the proposed method is validated through simulation experiments based on the actual power data of the PV plant. The results show that the developed methods can effectively utilize partial PV power generation to produce hydrogen, improve PV utilization, and the combined output power of PV plant and HESS can fulfill the grid-connected standard.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314677","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 : 2024-09-23DOI: 10.1016/j.ijhydene.2024.09.228
This article presented a robust plan for an off-grid charging station (OGCS) for electric vehicles (EVs) and hydrogen vehicles (HVs) based on a photovoltaic (PV) system and a hydrogen storage system (HSS). This OGCS simultaneously supplies HVs and EVs continuously throughout the day. Also, HSS and fuel cell (FC) systems have been allocated in the OGCS to be used when we do not have access to the power of the PV system. In addition, a diesel generator (DG) is also designed to prevent in cases where we have extreme uncertainty, including the lack of energy in the PV system and the high load of the system, which may lead to load interruption. Uncertainties of electric and hydrogen loads of EVs and HVs in addition to PV production power are simulated using scenario-based stochastic optimization technique (SOT). Finally, a new framework based on stochastic p-robust optimization technique (SPROT) is applied to optimize the maximum relative regret (MRR) in the worst scenario in order to achieve robust planning in the uncertain environment. The obtained results from the proposed SPROT are compared with SOT. The compared results indicate a 4.51% raise in the average cost in SPROT and a 45.73% decrease in MRR that leads to robust planning. Finally, installed capacity of PV system will decrease from 1688 to 1685 kW, while installed capacity of DG will increase from 78 to 123 kW.
{"title":"Planning of a charging station for electric and hydrogen vehicles under hydrogen storage and fuel cell systems using a novel stochastic p-robust optimization technique","authors":"","doi":"10.1016/j.ijhydene.2024.09.228","DOIUrl":"10.1016/j.ijhydene.2024.09.228","url":null,"abstract":"<div><div>This article presented a robust plan for an off-grid charging station (OGCS) for electric vehicles (EVs) and hydrogen vehicles (HVs) based on a photovoltaic (PV) system and a hydrogen storage system (HSS). This OGCS simultaneously supplies HVs and EVs continuously throughout the day. Also, HSS and fuel cell (FC) systems have been allocated in the OGCS to be used when we do not have access to the power of the PV system. In addition, a diesel generator (DG) is also designed to prevent in cases where we have extreme uncertainty, including the lack of energy in the PV system and the high load of the system, which may lead to load interruption. Uncertainties of electric and hydrogen loads of EVs and HVs in addition to PV production power are simulated using scenario-based stochastic optimization technique (SOT). Finally, a new framework based on stochastic p-robust optimization technique (SPROT) is applied to optimize the maximum relative regret (MRR) in the worst scenario in order to achieve robust planning in the uncertain environment. The obtained results from the proposed SPROT are compared with SOT. The compared results indicate a 4.51% raise in the average cost in SPROT and a 45.73% decrease in MRR that leads to robust planning. Finally, installed capacity of PV system will decrease from 1688 to 1685 kW, while installed capacity of DG will increase from 78 to 123 kW.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314755","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 : 2024-09-23DOI: 10.1016/j.ijhydene.2024.09.265
The growing global population needs energy from clean and renewable resources to meet present and future demands. Ideally, green hydrogen is commonly considered the key to overcoming the energy problem and the future energy standard. One of the most promising technologies for the development of the hydrogen economy is electrolysis water splitting (WS) hydrogen (H2) production; nevertheless, developing highly efficient environmentally sustainable electrocatalysts remains a serious issue for this technology. Transition metals (TMs) have achieved substantial progress in recent years, as a structural-based electrocatalyst developing especially noteworthy attention for the hydrogen evolution process (HER). These features have been proven to constitute the perfect electrocatalyst due to their advantages such as low cost, efficiency, stability, a large number of active sites, and great surface. This comprehensive review explains TMs-based chalcogenides and particular structural arrangements of multi-dimensional (1D, 2D, and 3D) electrocatalysts on different substrates for WS hydrogen production. The reaction process, the importance of the electrocatalyst, the advantages of the structural materials, and the efficiency that fluctuates with phase dimensions, have been investigated. Finally, the present issues and prospects of structural materials for WS were investigated in terms of HER and the perspective of this field was presented.
不断增长的全球人口需要来自清洁和可再生资源的能源，以满足当前和未来的需求。理想情况下，绿色氢气通常被认为是解决能源问题和未来能源标准的关键。发展氢经济最有前途的技术之一是电解水分裂制氢（WS）技术；然而，开发高效、环境可持续的电催化剂仍然是该技术面临的一个严峻问题。近年来，过渡金属（TMs）取得了长足的进步，作为一种基于结构的电催化剂，它在氢进化过程（HER）中的应用尤其值得关注。这些特性已被证明是完美的电催化剂，因为它们具有成本低、效率高、稳定性好、活性位点多和表面积大等优点。本综述介绍了基于 TMs 的铬化物以及用于 WS 制氢的不同基底上的多维（1D、2D 和 3D ）电催化剂的特殊结构排列。研究了反应过程、电催化剂的重要性、结构材料的优势以及随相尺寸波动的效率。最后，从 HER 的角度研究了 WS 结构材料的当前问题和前景，并展望了这一领域的前景。
{"title":"A comprehensive review and perspective of recent research developments, and accomplishments on structural-based catalysts; 1D, 2D, and 3D nanostructured electrocatalysts for hydrogen energy production","authors":"","doi":"10.1016/j.ijhydene.2024.09.265","DOIUrl":"10.1016/j.ijhydene.2024.09.265","url":null,"abstract":"<div><div>The growing global population needs energy from clean and renewable resources to meet present and future demands. Ideally, green hydrogen is commonly considered the key to overcoming the energy problem and the future energy standard. One of the most promising technologies for the development of the hydrogen economy is electrolysis water splitting (WS) hydrogen (H<sub>2</sub>) production; nevertheless, developing highly efficient environmentally sustainable electrocatalysts remains a serious issue for this technology. Transition metals (TMs) have achieved substantial progress in recent years, as a structural-based electrocatalyst developing especially noteworthy attention for the hydrogen evolution process (HER). These features have been proven to constitute the perfect electrocatalyst due to their advantages such as low cost, efficiency, stability, a large number of active sites, and great surface. This comprehensive review explains TMs-based chalcogenides and particular structural arrangements of multi-dimensional (1D, 2D, and 3D) electrocatalysts on different substrates for WS hydrogen production. The reaction process, the importance of the electrocatalyst, the advantages of the structural materials, and the efficiency that fluctuates with phase dimensions, have been investigated. Finally, the present issues and prospects of structural materials for WS were investigated in terms of HER and the perspective of this field was presented.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314653","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 : 2024-09-23DOI: 10.1016/j.ijhydene.2024.09.232
The Gd-doped CeO2 (GDC) diffusion barrier between the zirconia-based electrolyte and the LSCF-based cathode in a solid-oxide fuel cell (SOFC) is essential for preventing the formation of Sc2ZrO3 as a secondary phase. However, the reaction between ceria and zirconia at high temperatures (>1300 °C) impedes the formation of a highly dense GDC layer. Herein, we present a cost-effective approach for fabricating a highly dense GDC diffusion barrier layer at lower sintering temperatures by filling the pores of the GDC skeleton using a gelatin or polyvinylpyrrolidone (PVP) solution as a chelating agent for GDC cations. We investigated the interaction between the cations and the chelating agent molecules and its effect on the diffusion barrier. In addition, the flow behavior of the pore-filling solution was evaluated to determine its penetrability. The proposed method yielded a pore-filled GDC (PF-GDC) interlayer with enhanced density at 1000 °C, a remarkable 250 °C below the conventional sintering temperature for a porous GDC interlayer. The effectiveness of the PF-GDC was investigated by analyzing the performance of electrolyte-supported cells (ESCs) and anode-supported cells (ASCs). On ASCs, the observed peak power density at 800 °C was enhanced 1.5-fold, from 1.91 W⋅cm−2 (porous GDC sintered at 1250 °C) to 2.61 W⋅cm−2 (PF-GDC sintered at 1200 °C). These findings highlight the potential for pore-filling methods to improve the performance of SOFCs.
{"title":"Enhanced densification of screen-printed GDC interlayers for solid oxide fuel cells using nitrate-based precursor in various chelating agents as pore-filling solution","authors":"","doi":"10.1016/j.ijhydene.2024.09.232","DOIUrl":"10.1016/j.ijhydene.2024.09.232","url":null,"abstract":"<div><div>The Gd-doped CeO<sub>2</sub> (GDC) diffusion barrier between the zirconia-based electrolyte and the LSCF-based cathode in a solid-oxide fuel cell (SOFC) is essential for preventing the formation of Sc<sub>2</sub>ZrO<sub>3</sub> as a secondary phase. However, the reaction between ceria and zirconia at high temperatures (>1300 °C) impedes the formation of a highly dense GDC layer. Herein, we present a cost-effective approach for fabricating a highly dense GDC diffusion barrier layer at lower sintering temperatures by filling the pores of the GDC skeleton using a gelatin or polyvinylpyrrolidone (PVP) solution as a chelating agent for GDC cations. We investigated the interaction between the cations and the chelating agent molecules and its effect on the diffusion barrier. In addition, the flow behavior of the pore-filling solution was evaluated to determine its penetrability. The proposed method yielded a pore-filled GDC (PF-GDC) interlayer with enhanced density at 1000 °C, a remarkable 250 °C below the conventional sintering temperature for a porous GDC interlayer. The effectiveness of the PF-GDC was investigated by analyzing the performance of electrolyte-supported cells (ESCs) and anode-supported cells (ASCs). On ASCs, the observed peak power density at 800 °C was enhanced 1.5-fold, from 1.91 W⋅cm<sup>−2</sup> (porous GDC sintered at 1250 °C) to 2.61 W⋅cm<sup>−2</sup> (PF-GDC sintered at 1200 °C). These findings highlight the potential for pore-filling methods to improve the performance of SOFCs.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314676","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 : 2024-09-23DOI: 10.1016/j.ijhydene.2024.09.216
Studying the synergistic effects of dilution gases and hydrogen on the laminar combustion characteristics and NOX-emission concentrations of methane/air can contribute to achieving efficient and clean natural-gas combustion. This study quantitatively analyzes the impact of N2 and CO2 as dilution gases on the laminar combustion characteristics and NOX emissions of methane/air under different equivalence ratios. The virtual gases FN2 and FCO2 are introduced to distinguish between the physical and chemical effects of the dilution gases. Subsequently, the effect of hydrogen addition on the laminar combustion characteristics and NOX emissions of a methane/5% dilution gas/air mixture is investigated. Finally, the synergistic effects of the dilution gases and hydrogen on the laminar flame speed and NOX-emission concentrations of methane/air under various blending conditions are discussed. The results indicate that CO2 exhibits a more substantial reduction in laminar flame speed, flame temperature, key radical concentrations, and NOX-emission concentrations than N2, primarily because of its physical effects. N2 has minimal chemical effects, but marginally increases NOX emissions. The addition of hydrogen increases the laminar flame speed and key radical concentrations of the methane/dilution gas/air mixture. however, significant differences in the NOX-concentration trends with increasing hydrogen-blending ratios are observed for the three equivalence ratios (Φ = 0.7,1.0,1.4). Selecting appropriate blending ratios of dilution gases and hydrogen can simultaneously enhance the laminar flame speed of methane/air while reducing the NOX-emission concentrations. This study provides valuable insights into the optimization of the blending ratio of hydrogen-enriched natural-gas engines coupled with exhaust-gas recirculation.
{"title":"Synergistic effects of dilution gases and hydrogen on methane/air laminar combustion characteristics and NOX-emission concentrations","authors":"","doi":"10.1016/j.ijhydene.2024.09.216","DOIUrl":"10.1016/j.ijhydene.2024.09.216","url":null,"abstract":"<div><div>Studying the synergistic effects of dilution gases and hydrogen on the laminar combustion characteristics and NO<sub>X</sub>-emission concentrations of methane/air can contribute to achieving efficient and clean natural-gas combustion. This study quantitatively analyzes the impact of N<sub>2</sub> and CO<sub>2</sub> as dilution gases on the laminar combustion characteristics and NO<sub>X</sub> emissions of methane/air under different equivalence ratios. The virtual gases FN<sub>2</sub> and FCO<sub>2</sub> are introduced to distinguish between the physical and chemical effects of the dilution gases. Subsequently, the effect of hydrogen addition on the laminar combustion characteristics and NO<sub>X</sub> emissions of a methane/5% dilution gas/air mixture is investigated. Finally, the synergistic effects of the dilution gases and hydrogen on the laminar flame speed and NO<sub>X</sub>-emission concentrations of methane/air under various blending conditions are discussed. The results indicate that CO<sub>2</sub> exhibits a more substantial reduction in laminar flame speed, flame temperature, key radical concentrations, and NO<sub>X</sub>-emission concentrations than N<sub>2</sub>, primarily because of its physical effects. N<sub>2</sub> has minimal chemical effects, but marginally increases NO<sub>X</sub> emissions. The addition of hydrogen increases the laminar flame speed and key radical concentrations of the methane/dilution gas/air mixture. however, significant differences in the NO<sub>X</sub>-concentration trends with increasing hydrogen-blending ratios are observed for the three equivalence ratios (Φ = 0.7,1.0,1.4). Selecting appropriate blending ratios of dilution gases and hydrogen can simultaneously enhance the laminar flame speed of methane/air while reducing the NO<sub>X</sub>-emission concentrations. This study provides valuable insights into the optimization of the blending ratio of hydrogen-enriched natural-gas engines coupled with exhaust-gas recirculation.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314752","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 : 2024-09-23DOI: 10.1016/j.ijhydene.2024.09.145
Green hydrogen, produced using renewable energy sources, represents a critical component in the transition to sustainable energy systems due to its clean and versatile nature. This research investigates the dynamic behavior of bubbles within the serpentine flow field of a Proton Exchange Membrane Water Electrolysis (PEMWE) cell, aiming to enhance the understanding of two-phase flow dynamics and improve the efficiency of green hydrogen production. Utilizing the Volume of Fluid (VOF) method, a three-dimensional unsteady model was developed to simulate the flow dynamics at the anode of a PEMWE system. The study explores the transition of bubbles from bubbly flow to slug and annular flow, highlighting the significant impact of bubble formation on mass transport and overall cell performance. The results demonstrate that larger bubbles impede liquid water delivery to reaction sites and cause unstable pressure drops. The investigation also examines the influence of wall contact angles on bubble behavior, revealing that hydrophobic surfaces lead to increased gas coverage and more oxygen accumulation inside the channel, which hinders mass transport. These findings underscore the necessity for optimized flow channel designs and enhanced surface treatments to mitigate bubble coalescence and improve PEMWE performance.
{"title":"Numerical analysis of bubble behavior in proton exchange membrane water electrolyzer flow field with serpentine channel","authors":"","doi":"10.1016/j.ijhydene.2024.09.145","DOIUrl":"10.1016/j.ijhydene.2024.09.145","url":null,"abstract":"<div><div>Green hydrogen, produced using renewable energy sources, represents a critical component in the transition to sustainable energy systems due to its clean and versatile nature. This research investigates the dynamic behavior of bubbles within the serpentine flow field of a Proton Exchange Membrane Water Electrolysis (PEMWE) cell, aiming to enhance the understanding of two-phase flow dynamics and improve the efficiency of green hydrogen production. Utilizing the Volume of Fluid (VOF) method, a three-dimensional unsteady model was developed to simulate the flow dynamics at the anode of a PEMWE system. The study explores the transition of bubbles from bubbly flow to slug and annular flow, highlighting the significant impact of bubble formation on mass transport and overall cell performance. The results demonstrate that larger bubbles impede liquid water delivery to reaction sites and cause unstable pressure drops. The investigation also examines the influence of wall contact angles on bubble behavior, revealing that hydrophobic surfaces lead to increased gas coverage and more oxygen accumulation inside the channel, which hinders mass transport. These findings underscore the necessity for optimized flow channel designs and enhanced surface treatments to mitigate bubble coalescence and improve PEMWE performance.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314658","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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