Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-nob...Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-noble metal catalysts and hydrocarbon-based ionomers as membrane[1].However,despite of extensive researches on non-noble metal catalysts such as Co[2].展开更多
Modern aircraft tend to use fuel thermal management systems to cool onboard heat sources.However,the design of heat transfer architectures for fuel thermal management systems relies on the experience of the engineers ...Modern aircraft tend to use fuel thermal management systems to cool onboard heat sources.However,the design of heat transfer architectures for fuel thermal management systems relies on the experience of the engineers and lacks theoretical guidance.This paper proposes a concise graph representation method based on graph theory for fuel thermal management systems,which can represent all possible connections between subsystems.A generalized optimization algorithm is proposed for fuel thermal management system architecture to minimize the heat sink.This algorithm can autonomously arrange subsystems with heat production differences and efficiently utilize the architecture of the fuel heat sink.At the same time,two evaluation indices are proposed from the perspective of subsystems.These indices intuitively and clearly show that the reason for the high efficiency of heat sink utilization is the balanced and moderate cooling of each subsystem and verify the rationality of the architecture optimization method.A set of simulations are also conducted,which demonstrate that the fuel tank temperature has no effect on the performance of the architecture.This paper provides a reference for the architectural design of aircraft fuel thermal management systems.The metrics used in this paper can also be utilized to evaluate the existing architecture.展开更多
Sustainable energy technologies,particularly fuel cells,are gaining attraction for their potential to reduce carbon emissions and provide efficient power.Proton exchange membrane fuel cells(PEMFCs)have been central to...Sustainable energy technologies,particularly fuel cells,are gaining attraction for their potential to reduce carbon emissions and provide efficient power.Proton exchange membrane fuel cells(PEMFCs)have been central to this development.However,one persistent issue with lowtemperature PEMFCs is the dehydration of Nafion ionomer at elevated temperatures,which severely limits proton conductivity.Wang et al.tackle this by introducing a covalent organic framework(COF)interwoven with Nafion,addressing the challenge of maintaining proton conductivity and oxygen transport in medium temperatures(100–120℃).展开更多
Metal-Supported Solid Oxide Fuel Cells(MS-SOFCs)hold significant potential for driving the energy transition.These electrochemical devices represent the most advanced generation of Solid Oxide Fuel Cell(SOFCs)and can ...Metal-Supported Solid Oxide Fuel Cells(MS-SOFCs)hold significant potential for driving the energy transition.These electrochemical devices represent the most advanced generation of Solid Oxide Fuel Cell(SOFCs)and can pave the way for mass production and wider adoption than Proton Exchange Membrane Fuel Cells(PEMFCs)due to their fuel flexibility,higher power density and the absence of noble metals in the fabrication processes.This review examines the state-of-the-art of SOFCs and MS-SOFCs,presenting perspectives and research directions for these key technological devices,highlighting novel materials,techniques,architectures,devices,and degradation mechanisms to address current challenges and future opportunities.Techniques such as infiltration/impregnation,ex-solution catalyst synthesis,and the use of a pre-catalytic reformer layer are discussed as their impact on efficiency and prolonged activity.These concepts are also described and connected with well-dispersed nano particles,hindrance of coarsening,and an increased number of Triple Phase Boundaries(TPBs).This review also describes the synergistic use of reformers with MS-SOFCs to compose solutions in energy generation from readily available fuels.Lastly,the End-of-Life(EoL),recycling,and life-cycle assessments(LCAs)of the Fuel Cell Hybrid Electric Vehicles(FCHEVs)were discussed.LCAs comparing Fuel Cell Electric Vehicles(FCEVs)equipped with(PEMFCs)and FCHEVs equipped with MS-SOFCs,both powered with hydrogen(H_(2))generated by different routes were compared.This review aims to provide valuable insights into these key technological devices,emphasizing the importance of robust research and development to enhance performance and lifespan while reducing costs and environmental impact.展开更多
Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it ...Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it is necessary for the quality of hydrogen to adhere to the standards set by ISO 14687:2019,which sets maximum limits for 14 impurities in hydrogen,aiming to prevent any degradation of fuel cell performance.Ammonia(NH_(3))is a prominent pollutant in fuel cells,and accurate measurements of its concentration are crucial for hydrogen fuel cell quantity.In this study,a novel detection platform was developed for determining NH_(3)in real hydrogen samples.The online analysis platform integrates a self-developed online dilution module with a Fourier transform infrared spectrometer(ODM-FTIR).The ODM-FTIR can be operated fully automatically with remote operation.Under the optimum conditions,this method achieved a wide linear range between(50∼1000)nmol/mol.The limit of detection(LOD)was as low as 2 nmol/mol with a relative standard deviation(RSD,n=7)of 3.6%at a content of 50 nmol/mol.To ensure that the quality of the hydrogen products meets the requirement of proton exchange membrane fuel cell vehicles(PEMFCV),the developed ODM-FTIR system was applied to monitor the NH_(3)content in Chengdu Hydrogen Energy Co.,Ltd.for 21 days during Chengdu 2021 FISU World University Games.The proposed method retains several unique advantages,including a low detection limit,excellent repeatability,high accuracy,high speed,good stability,and calibration flexibility.It is an effective analytical method for accurately quantifying NH_(3)in hydrogen,especially suitable for online analysis.It also provides a new idea for the analysis of other impurity components in hydrogen.展开更多
Photoinduced[2+2]cycloaddition of biomass-derived cycloolefin is a promising approach to synthesize high-energy bio-fuels,however,the conversion efficiency and selectivity are still low.Herein,we provide an acid-promo...Photoinduced[2+2]cycloaddition of biomass-derived cycloolefin is a promising approach to synthesize high-energy bio-fuels,however,the conversion efficiency and selectivity are still low.Herein,we provide an acid-promoted photocycloaddition approach to synthesize a new kind of spiral fuel from biomass-derived cyclohexanone (CHOE) and camphene (CPE).BrΦnsted acids show higher catalytic activity than Lewis acids,and acetic acid (HOAc) possesses the best catalytic performance,with CHOE conversion up to 99.1%.Meanwhile,the HOAc-catalytic effect has been confirmed for[2+2]photocycloaddition of other biomass-derived ketenes and olefins.The catalytic mechanism and dynamics have been investigated,and show that HOAc can bond with C=O groups of CHOE to form H–CHOE complex,which leads to higher light adsorption and longer triplet lifetime.Meanwhile,H–CHOE complex reduces the energy gap between CHOE LUMO and CPE HOMO,shortens the distance of ring-forming atoms,and then decreases the energy barrier (from 103.3 kcal mol^(-1)to 95.8 kcal mol^(-1)) of rate-limiting step.After hydrodeoxygenation,the targeted bio-spiral fuel shows high density of 0.992 g cm^(-3),high neat heat of combustion of 41.89 MJ L^(-1),low kinetic viscosity of 5.69 mm^(2)s^(-1)at 20℃,which is very promising to serve as high-performance aerospace fuel.展开更多
The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments o...The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments on homogeneous fuels but has not been validated for conifer-deciduous mixed fuel.In this study,Pinus koraiensis and Quercus mongolica litter was used in a laboratory burning experiment to simulate surface fire spread in the field.The effects of fuel moisture content,mixed fuel ratio and slope on spread rate were analyzed.The optimum packing ratio,moisture-damping coefficient and slope parameters in the Rothermel model were modified using the measured spread rate which was positively correlated with slope and negatively with fuel moisture content.As the Q.mongolica load increased,the spread rate increased and was highest at a fuel ratio of 4:6.The model with modified optimal packing ratio and slope parameters has a significantly lower spread rate prediction error than the unmodified model.The spread rate prediction accuracy was significantly improved after modifying the model parameters based on spread rates from laboratory burning simulations.展开更多
This paper provides a comprehensive review of various experimental methods used to study carbon corrosion in automotive polymer exchange membrane fuel cells.Quantifying the extent of carbon corrosion is essential for ...This paper provides a comprehensive review of various experimental methods used to study carbon corrosion in automotive polymer exchange membrane fuel cells.Quantifying the extent of carbon corrosion is essential for advancing the technology and implementing effective mitigation strategies.While studying degradation events directly within a real-world fuel cell vehicle offers the most reliable insights,the high costs and time demands make it necessary to develop specialised experimental techniques that provide high-resolution data more efficiently and cost-effectively.This review explores the various experimental approaches utilised in automotive application induced carbon corrosion studies globally,including load profiles,test setups,break-in procedures,and cell recovery protocols.In this paper,emphasis is placed on the standardised procedures proposed by leading institutions worldwide,accompanied by critical discussions on these protocols.Furthermore,the paper highlights modified or innovative procedures developed by smaller institutions,universities,and individual researchers,thereby offering a comprehensive overview essential for carbon corrosion analysis.The review also discusses the fundamental principles,benefits,and limitations of various procedures,offering guidance on selecting the most appropriate approach for a given study.Lastly,it addresses the limitations within the current body of literature and outlines potential future prospects.展开更多
Carbon emissions from wastewater treatment contribute to global warming and have received widespread attention.It is necessary to seek low-carbon wastewater treatment technologies.Microbial fuel cells(MFC)and osmotic ...Carbon emissions from wastewater treatment contribute to global warming and have received widespread attention.It is necessary to seek low-carbon wastewater treatment technologies.Microbial fuel cells(MFC)and osmotic microbial fuel cells(Os MFC)are low-carbon technologies that enable both wastewater treatment and energy recovery.In this study,MFC and Os MFC were used to treat sulfamethoxazole(SMX)wastewater,and direct carbon emissions during operation was calculated.The highest SMX removal rate can reach about 40%.Simultaneously,the CH_(4)emission factor was significantly reduced to<6 g CO_(2)/kg of chemical oxygen demand.The accumulation of SMX-degrading bacteria competed with methanogens for carbon source utilization,leading to a significant decrease in the relative abundance of methanogens.It is hoped that this study can provide a sustainable approach to antibiotic wastewater treatment and promote the development of low-carbon wastewater treatment technologies.展开更多
Significant advances in battery and fuel cell technologies over the past decade have catalyzed the transition toward electrified transportation systems and large-scale renewable energy integration.Concurrent with thes...Significant advances in battery and fuel cell technologies over the past decade have catalyzed the transition toward electrified transportation systems and large-scale renewable energy integration.Concurrent with these developments,the interdisciplinary role of mechanics has emerged as a critical research frontier.展开更多
Hydrogen fuel cell ships are one of the key solutions to achieving zero carbon emissions in shipping.Multi-fuel cell stacks(MFCS)systems are frequently employed to fulfill the power requirements of high-load power equ...Hydrogen fuel cell ships are one of the key solutions to achieving zero carbon emissions in shipping.Multi-fuel cell stacks(MFCS)systems are frequently employed to fulfill the power requirements of high-load power equipment on ships.Compared to single-stack system,MFCS may be difficult to apply traditional energy management strategies(EMS)due to their complex structure.In this paper,a two-layer power allocation strategy for MFCS of a hydrogen fuel cell ship is proposed to reduce the complexity of the allocation task by splitting it into each layer of the EMS.The first layer of the EMSis centered on the Nonlinear Model Predictive Control(NMPC).The Northern Goshawk Optimization(NGO)algorithm is used to solve the nonlinear optimization problem in NMPC,and the local fine search is performed using sequential quadratic programming(SQP).Based on the power allocation results of the first layer,the second layer is centered on a fuzzy rule-based adaptive power allocation strategy(AP-Fuzzy).The membership function bounds of the fuzzy controller are related to the aging level of the MFCS.The Particle Swarm Optimization(PSO)algorithm is used to optimize the parameters of the residual membership function to improve the performance of the proposed strategy.The effectiveness of the proposed EMS is verified by comparing it with the traditional EMS.The experimental results show that the EMS proposed in this paper can ensure reasonable hydrogen consumption,slow down the FC aging and equalize its performance,effectively extend the system life,and ensure that the ship has good endurance after completing the mission.展开更多
Photocycloaddition affords opportunities to engage in advanced fuels with high-strained cyclobutyl-containing structures.Herein,the one-step route for the synthesis of high-energy-density caged fuel,tetracyclo[4.2.1.0...Photocycloaddition affords opportunities to engage in advanced fuels with high-strained cyclobutyl-containing structures.Herein,the one-step route for the synthesis of high-energy-density caged fuel,tetracyclo[4.2.1.0^(2.5).0^(3,7)]nonane(TCN)with high-strained four-membered structure,has been developed via photosensitized[2+2]cycloaddition of 5-vinyl-2-norbornene(VNB).The reaction conditions are optimized to obtain a high conversion of VNB of 91.9%.The triplet quenching and Stern-Volmer quenching studies indicate that[2+2]photocycloaddition follows the triplet-triplet energy transfer process,and a kinetic model is expressed as a reaction rate equation correlated with the incident light flux.Importantly,the obtained TCN shows a high density of 1.003 g·cm^(-3)and volumetric net heat of combustion of 42.31 MJ·L^(-1),which can serve as an excellent high-energy additive for blending with liquid fuels.展开更多
Solid oxide fuel cell(SOFC)is a promising power generation technology with high efficiency and can operate with a wide range of fuels.Although H2 delivery and storage are still hurdles,natural gas is readily accessibl...Solid oxide fuel cell(SOFC)is a promising power generation technology with high efficiency and can operate with a wide range of fuels.Although H2 delivery and storage are still hurdles,natural gas is readily accessible through existing pipeline infrastructure and therefore stands as a viable fuel candidate for SOFC.Owing to the high operating temperature,the methane in natural gas can be directly reformed in the anode of an SOFC.However,mechanical failure remains a critical issue and hinders the prevalence of traditional planar SOFCs.A novel flat-tubular structure with symmetrical double-sided cathodes was previously proposed to improve mechanical durability.In this work,the performance of a methane-fueled SOFC with symmetrical double-sided cathodes is analyzed with a numerical multiphysics model.The distributions of different physical fields in the SOFC are investigated.Special attention is paid to stress analysis,which is closely related to the mechanical stability of an SOFC.Furthermore,the CH_(4)-fueled and H_(2)-fueled SOFCs are also compared in terms of the distribution of thermal stress.A lower first principal stress is observed for CH_(4)-fueled flat-tubular SOFC,demonstrating a reduced probability of mechanical failures and potentially extended lifespan.展开更多
Objective Burning solid cooking fuel contributes to household air pollution and is associated with frailty.However,how solid cooking fuel use contributes to the development of frailty has not been well illustrated.Met...Objective Burning solid cooking fuel contributes to household air pollution and is associated with frailty.However,how solid cooking fuel use contributes to the development of frailty has not been well illustrated.Methods This study recruited 8,947 participants aged≥45 years from the China Health and Retirement Longitudinal Study,2011–2018.Group-based trajectory modeling was employed to identify frailty trajectories.Multinomial logistic regression was used to assess the association between solid cooking fuel use and frailty trajectories.Population-attributable fractions were used to estimate the frailty burden from solid fuel use.Results We identified three frailty trajectories:low-stable(n=5,789),moderate-increasing(n=2,603),and fast-increasing(n=555).Solid fuel use was associated with higher odds of being in the moderate-increasing(OR:1.24,95%CI:1.08–1.42)and fast-increasing(OR:1.48,95%CI:1.14–1.92)trajectories.These associations were strengthened by longer solid fuel use(P for trend<0.001).Switching to clean fuel significantly reduced the risk of being in these trajectories compared with persistent solid fuel users.Without solid fuel,8%of moderate-and 19%of fast-increasing trajectories demonstrated frailty development like the low-stable group.Conclusion Solid cooking fuel use is associated with frailty trajectories in middle-aged and older Chinese populations.展开更多
Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial ...Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial applications.Among them,methanol is widely used as a hydrogen source,and CO is inevitably generated during its oxidation process.Even a small amount of CO(∼20 ppm)strongly binds to Pt used as a catalyst,and deactivates it.In addition to CO,surface adsorption of organic cations by binder or ionomer use in alkaline fuel cells is also one of the poisoning issues to be overcome.Herein,we propose FePt bimetallic catalysts that can resist unavoidable CO and organic cation poisoning.Our synthetic strategy,including annealing and acid treatment,allows the catalysts to possess different alloying degrees and surface structures,which in turn induce different levels of resistance to CO and organic-cation poisonings.The correlation between the surface and bulk structures of the catalysts and poisoning resistance was elucidated through X-ray photoemission spectroscopy and electrochemical analysis.The results revealed that an FePt catalyst having an ordered atomic arrangement displayed a better poisoning resistance than that having a disordered arrangement.展开更多
3D printing technology enhances the combustion characteristics of hybrid rocket fuels by enabling complex geometries. However, improvements in regression rates and energy properties of monotonous 3D printed fuels have...3D printing technology enhances the combustion characteristics of hybrid rocket fuels by enabling complex geometries. However, improvements in regression rates and energy properties of monotonous 3D printed fuels have been limited. This study explores the impact of poly(vinylidene fluoride) and polydopamine-coated aluminum particles on the thermal and combustion properties of 3D printed hybrid rocket fuels. Physical self-assembly and anti-solvent methods were employed for constructing composite μAl particles. Characterization using SEM, XRD, XPS, FTIR, and μCT revealed a core-shell structure and homogeneous elemental distribution. Thermal analysis showed that PVDF coatings significantly increased the heat of combustion for aluminum particles, with maximum enhancement observed in μAl@PDA@PVDF(denoted as μAl@PF) at 6.20 k J/g. Subsequently, 3D printed fuels with varying pure and composite μAl particle contents were prepared using 3D printing. Combustion tests indicated higher regression rates for Al@PF/Resin composites compared to pure resin, positively correlating with particle content. The fluorocarbon-alumina reaction during the combustion stage intensified Al particle combustion, reducing residue size. A comprehensive model based on experiments provides insights into the combustion process of PDA and PVDF-coated droplets. This study advances the design of 3D-printed hybrid rocket fuels, offering strategies to improve regression rates and energy release, crucial for enhancing solid fuel performance for hybrid propulsion.展开更多
Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longr...Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longrange continuous structure of the nanofiber,ion-charged groups can be induced to form long-range continuous ion transfer channels in the nanofiber composite membrane,significantly increasing the ion conductivity of the membrane.This review stands apart from previous endeavors by offering a comprehensive overview of the strategies employed over the past decade in utilizing both electrospun and natural nanofibers as key components of proton exchange membranes and anion exchange membranes for fuel cells.Electrospun nanofibers are categorized based on their material properties into two primary groups:(1)ionomer nanofibers,inherently endowed with the ability to conduct H+(such as perfluorosulfonic acid or sulfonated poly(ether ether ketone))or OH-(e.g.,FAA-3),and(2)nonionic polymer nanofibers,comprising inert polymers like polyvinylidene difluoride,polytetrafluoroethylene,and polyacrylonitrile.Notably,the latter often necessitates surface modifications to impart ion transport channels,given their inherent proton inertness.Furthermore,this review delves into the recent progress made with three natural nanofibers derived from biodegradable cellulose—cellulose nanocrystals,cellulose nanofibers,and bacterial nanofibers—as crucial elements in polyelectrolyte membranes.The effect of the physical structure of such nanofibers on polyelectrolyte membrane properties is also briefly discussed.Lastly,the review emphasizes the challenges and outlines potential solutions for future research in the field of nanofiber-based polyelectrolyte membranes,aiming to propel the development of high-performance polymer electrolyte fuel cells.展开更多
The liquid cooling system(LCS)of fuel cells is challenged by significant time delays,model uncertainties,pump and fan coupling,and frequent disturbances,leading to overshoot and control oscillations that degrade tempe...The liquid cooling system(LCS)of fuel cells is challenged by significant time delays,model uncertainties,pump and fan coupling,and frequent disturbances,leading to overshoot and control oscillations that degrade temperature regulation performance.To address these challenges,we propose a composite control scheme combining fuzzy logic and a variable-gain generalized supertwisting algorithm(VG-GSTA).Firstly,a one-dimensional(1D)fuzzy logic controler(FLC)for the pump ensures stable coolant flow,while a two-dimensional(2D)FLC for the fan regulates the stack temperature near the reference value.The VG-GSTA is then introduced to eliminate steady-state errors,offering resistance to disturbances and minimizing control oscillations.The equilibrium optimizer is used to fine-tune VG-GSTA parameters.Co-simulation verifies the effectiveness of our method,demonstrating its advantages in terms of disturbance immunity,overshoot suppression,tracking accuracy and response speed.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22162014 and U24A2044).
文摘Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-noble metal catalysts and hydrocarbon-based ionomers as membrane[1].However,despite of extensive researches on non-noble metal catalysts such as Co[2].
文摘Modern aircraft tend to use fuel thermal management systems to cool onboard heat sources.However,the design of heat transfer architectures for fuel thermal management systems relies on the experience of the engineers and lacks theoretical guidance.This paper proposes a concise graph representation method based on graph theory for fuel thermal management systems,which can represent all possible connections between subsystems.A generalized optimization algorithm is proposed for fuel thermal management system architecture to minimize the heat sink.This algorithm can autonomously arrange subsystems with heat production differences and efficiently utilize the architecture of the fuel heat sink.At the same time,two evaluation indices are proposed from the perspective of subsystems.These indices intuitively and clearly show that the reason for the high efficiency of heat sink utilization is the balanced and moderate cooling of each subsystem and verify the rationality of the architecture optimization method.A set of simulations are also conducted,which demonstrate that the fuel tank temperature has no effect on the performance of the architecture.This paper provides a reference for the architectural design of aircraft fuel thermal management systems.The metrics used in this paper can also be utilized to evaluate the existing architecture.
基金financial support from the National Natural Science Foundation of China(No.22301139)the Natural Science Foundation of Jiangsu Province(No.BK 20230375).
文摘Sustainable energy technologies,particularly fuel cells,are gaining attraction for their potential to reduce carbon emissions and provide efficient power.Proton exchange membrane fuel cells(PEMFCs)have been central to this development.However,one persistent issue with lowtemperature PEMFCs is the dehydration of Nafion ionomer at elevated temperatures,which severely limits proton conductivity.Wang et al.tackle this by introducing a covalent organic framework(COF)interwoven with Nafion,addressing the challenge of maintaining proton conductivity and oxygen transport in medium temperatures(100–120℃).
基金the Fundacao de Amparo à Pesquisa do Estado de Sao Paulo(FAPESP,2022/02235-4,2017/11958-1,2017/11986-5,2014/02163-7)Fundacao de Apoio da UFMG(FUNDEP,27192-36,01-P-38465/2023)Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq,405675/2022-4,56405643/2022-5,302180/2022-2,306870/2021-5)。
文摘Metal-Supported Solid Oxide Fuel Cells(MS-SOFCs)hold significant potential for driving the energy transition.These electrochemical devices represent the most advanced generation of Solid Oxide Fuel Cell(SOFCs)and can pave the way for mass production and wider adoption than Proton Exchange Membrane Fuel Cells(PEMFCs)due to their fuel flexibility,higher power density and the absence of noble metals in the fabrication processes.This review examines the state-of-the-art of SOFCs and MS-SOFCs,presenting perspectives and research directions for these key technological devices,highlighting novel materials,techniques,architectures,devices,and degradation mechanisms to address current challenges and future opportunities.Techniques such as infiltration/impregnation,ex-solution catalyst synthesis,and the use of a pre-catalytic reformer layer are discussed as their impact on efficiency and prolonged activity.These concepts are also described and connected with well-dispersed nano particles,hindrance of coarsening,and an increased number of Triple Phase Boundaries(TPBs).This review also describes the synergistic use of reformers with MS-SOFCs to compose solutions in energy generation from readily available fuels.Lastly,the End-of-Life(EoL),recycling,and life-cycle assessments(LCAs)of the Fuel Cell Hybrid Electric Vehicles(FCHEVs)were discussed.LCAs comparing Fuel Cell Electric Vehicles(FCEVs)equipped with(PEMFCs)and FCHEVs equipped with MS-SOFCs,both powered with hydrogen(H_(2))generated by different routes were compared.This review aims to provide valuable insights into these key technological devices,emphasizing the importance of robust research and development to enhance performance and lifespan while reducing costs and environmental impact.
基金financial support by Sichuan Science and Technology,China(No.2023YFG0070).
文摘Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it is necessary for the quality of hydrogen to adhere to the standards set by ISO 14687:2019,which sets maximum limits for 14 impurities in hydrogen,aiming to prevent any degradation of fuel cell performance.Ammonia(NH_(3))is a prominent pollutant in fuel cells,and accurate measurements of its concentration are crucial for hydrogen fuel cell quantity.In this study,a novel detection platform was developed for determining NH_(3)in real hydrogen samples.The online analysis platform integrates a self-developed online dilution module with a Fourier transform infrared spectrometer(ODM-FTIR).The ODM-FTIR can be operated fully automatically with remote operation.Under the optimum conditions,this method achieved a wide linear range between(50∼1000)nmol/mol.The limit of detection(LOD)was as low as 2 nmol/mol with a relative standard deviation(RSD,n=7)of 3.6%at a content of 50 nmol/mol.To ensure that the quality of the hydrogen products meets the requirement of proton exchange membrane fuel cell vehicles(PEMFCV),the developed ODM-FTIR system was applied to monitor the NH_(3)content in Chengdu Hydrogen Energy Co.,Ltd.for 21 days during Chengdu 2021 FISU World University Games.The proposed method retains several unique advantages,including a low detection limit,excellent repeatability,high accuracy,high speed,good stability,and calibration flexibility.It is an effective analytical method for accurately quantifying NH_(3)in hydrogen,especially suitable for online analysis.It also provides a new idea for the analysis of other impurity components in hydrogen.
基金the support from National Key R&D Program of China (2021YFC2103704)the National Natural Science Foundation of China (22222808)+4 种基金the Natural Science Foundation of Shandong Province (ZR2023QB152)the Youth Innovation Team Plan of Shandong Province (2022KJ270)the China National Postdoctoral Program for Innovative Talents (BX20240251)the Aeronautical Science Foundation of China (2023Z073048003)the Haihe Laboratory of Sustainable Chemical Transformations。
文摘Photoinduced[2+2]cycloaddition of biomass-derived cycloolefin is a promising approach to synthesize high-energy bio-fuels,however,the conversion efficiency and selectivity are still low.Herein,we provide an acid-promoted photocycloaddition approach to synthesize a new kind of spiral fuel from biomass-derived cyclohexanone (CHOE) and camphene (CPE).BrΦnsted acids show higher catalytic activity than Lewis acids,and acetic acid (HOAc) possesses the best catalytic performance,with CHOE conversion up to 99.1%.Meanwhile,the HOAc-catalytic effect has been confirmed for[2+2]photocycloaddition of other biomass-derived ketenes and olefins.The catalytic mechanism and dynamics have been investigated,and show that HOAc can bond with C=O groups of CHOE to form H–CHOE complex,which leads to higher light adsorption and longer triplet lifetime.Meanwhile,H–CHOE complex reduces the energy gap between CHOE LUMO and CPE HOMO,shortens the distance of ring-forming atoms,and then decreases the energy barrier (from 103.3 kcal mol^(-1)to 95.8 kcal mol^(-1)) of rate-limiting step.After hydrodeoxygenation,the targeted bio-spiral fuel shows high density of 0.992 g cm^(-3),high neat heat of combustion of 41.89 MJ L^(-1),low kinetic viscosity of 5.69 mm^(2)s^(-1)at 20℃,which is very promising to serve as high-performance aerospace fuel.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFC1511603)the Fundamental Research Funds for the Central Universities(2572021BA04).
文摘The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments on homogeneous fuels but has not been validated for conifer-deciduous mixed fuel.In this study,Pinus koraiensis and Quercus mongolica litter was used in a laboratory burning experiment to simulate surface fire spread in the field.The effects of fuel moisture content,mixed fuel ratio and slope on spread rate were analyzed.The optimum packing ratio,moisture-damping coefficient and slope parameters in the Rothermel model were modified using the measured spread rate which was positively correlated with slope and negatively with fuel moisture content.As the Q.mongolica load increased,the spread rate increased and was highest at a fuel ratio of 4:6.The model with modified optimal packing ratio and slope parameters has a significantly lower spread rate prediction error than the unmodified model.The spread rate prediction accuracy was significantly improved after modifying the model parameters based on spread rates from laboratory burning simulations.
文摘This paper provides a comprehensive review of various experimental methods used to study carbon corrosion in automotive polymer exchange membrane fuel cells.Quantifying the extent of carbon corrosion is essential for advancing the technology and implementing effective mitigation strategies.While studying degradation events directly within a real-world fuel cell vehicle offers the most reliable insights,the high costs and time demands make it necessary to develop specialised experimental techniques that provide high-resolution data more efficiently and cost-effectively.This review explores the various experimental approaches utilised in automotive application induced carbon corrosion studies globally,including load profiles,test setups,break-in procedures,and cell recovery protocols.In this paper,emphasis is placed on the standardised procedures proposed by leading institutions worldwide,accompanied by critical discussions on these protocols.Furthermore,the paper highlights modified or innovative procedures developed by smaller institutions,universities,and individual researchers,thereby offering a comprehensive overview essential for carbon corrosion analysis.The review also discusses the fundamental principles,benefits,and limitations of various procedures,offering guidance on selecting the most appropriate approach for a given study.Lastly,it addresses the limitations within the current body of literature and outlines potential future prospects.
基金the Fundamental Research Funds for Central Public Research Institutes of China(No.2022YSKY14)the Fundamental Research Funds for the Central Publicinterest Scientific Institution(No.2023YSKY-07)。
文摘Carbon emissions from wastewater treatment contribute to global warming and have received widespread attention.It is necessary to seek low-carbon wastewater treatment technologies.Microbial fuel cells(MFC)and osmotic microbial fuel cells(Os MFC)are low-carbon technologies that enable both wastewater treatment and energy recovery.In this study,MFC and Os MFC were used to treat sulfamethoxazole(SMX)wastewater,and direct carbon emissions during operation was calculated.The highest SMX removal rate can reach about 40%.Simultaneously,the CH_(4)emission factor was significantly reduced to<6 g CO_(2)/kg of chemical oxygen demand.The accumulation of SMX-degrading bacteria competed with methanogens for carbon source utilization,leading to a significant decrease in the relative abundance of methanogens.It is hoped that this study can provide a sustainable approach to antibiotic wastewater treatment and promote the development of low-carbon wastewater treatment technologies.
文摘Significant advances in battery and fuel cell technologies over the past decade have catalyzed the transition toward electrified transportation systems and large-scale renewable energy integration.Concurrent with these developments,the interdisciplinary role of mechanics has emerged as a critical research frontier.
基金supported by the National Key R&D Program of China(2022YFB4301403).
文摘Hydrogen fuel cell ships are one of the key solutions to achieving zero carbon emissions in shipping.Multi-fuel cell stacks(MFCS)systems are frequently employed to fulfill the power requirements of high-load power equipment on ships.Compared to single-stack system,MFCS may be difficult to apply traditional energy management strategies(EMS)due to their complex structure.In this paper,a two-layer power allocation strategy for MFCS of a hydrogen fuel cell ship is proposed to reduce the complexity of the allocation task by splitting it into each layer of the EMS.The first layer of the EMSis centered on the Nonlinear Model Predictive Control(NMPC).The Northern Goshawk Optimization(NGO)algorithm is used to solve the nonlinear optimization problem in NMPC,and the local fine search is performed using sequential quadratic programming(SQP).Based on the power allocation results of the first layer,the second layer is centered on a fuzzy rule-based adaptive power allocation strategy(AP-Fuzzy).The membership function bounds of the fuzzy controller are related to the aging level of the MFCS.The Particle Swarm Optimization(PSO)algorithm is used to optimize the parameters of the residual membership function to improve the performance of the proposed strategy.The effectiveness of the proposed EMS is verified by comparing it with the traditional EMS.The experimental results show that the EMS proposed in this paper can ensure reasonable hydrogen consumption,slow down the FC aging and equalize its performance,effectively extend the system life,and ensure that the ship has good endurance after completing the mission.
基金the support from the National Natural Science Foundation of China(22408272,22222808,U24A20547)the Aeronautical Science Foundation of China(2023Z073048003)+1 种基金the China National Postdoctoral Program for Innovative Talents(BX20240251)the China Postdoctoral Science Foundation(2023M742592)。
文摘Photocycloaddition affords opportunities to engage in advanced fuels with high-strained cyclobutyl-containing structures.Herein,the one-step route for the synthesis of high-energy-density caged fuel,tetracyclo[4.2.1.0^(2.5).0^(3,7)]nonane(TCN)with high-strained four-membered structure,has been developed via photosensitized[2+2]cycloaddition of 5-vinyl-2-norbornene(VNB).The reaction conditions are optimized to obtain a high conversion of VNB of 91.9%.The triplet quenching and Stern-Volmer quenching studies indicate that[2+2]photocycloaddition follows the triplet-triplet energy transfer process,and a kinetic model is expressed as a reaction rate equation correlated with the incident light flux.Importantly,the obtained TCN shows a high density of 1.003 g·cm^(-3)and volumetric net heat of combustion of 42.31 MJ·L^(-1),which can serve as an excellent high-energy additive for blending with liquid fuels.
基金the National Natural Science Foundation of China(11802106,11932005,U20A20251,52102226,and 22109101)Department of Education of Guangdong Province,China(2021KCXTD006 and 2021KQNCX272)+1 种基金Science,Technology and Innovation Commission of Shenzhen Municipality,China(GJHZ20220913143009017 and JCYJ20210324093008021)Development and Reform Commission of Shenzhen Municipality,China(XMHT20220103004)is appreciated.
文摘Solid oxide fuel cell(SOFC)is a promising power generation technology with high efficiency and can operate with a wide range of fuels.Although H2 delivery and storage are still hurdles,natural gas is readily accessible through existing pipeline infrastructure and therefore stands as a viable fuel candidate for SOFC.Owing to the high operating temperature,the methane in natural gas can be directly reformed in the anode of an SOFC.However,mechanical failure remains a critical issue and hinders the prevalence of traditional planar SOFCs.A novel flat-tubular structure with symmetrical double-sided cathodes was previously proposed to improve mechanical durability.In this work,the performance of a methane-fueled SOFC with symmetrical double-sided cathodes is analyzed with a numerical multiphysics model.The distributions of different physical fields in the SOFC are investigated.Special attention is paid to stress analysis,which is closely related to the mechanical stability of an SOFC.Furthermore,the CH_(4)-fueled and H_(2)-fueled SOFCs are also compared in terms of the distribution of thermal stress.A lower first principal stress is observed for CH_(4)-fueled flat-tubular SOFC,demonstrating a reduced probability of mechanical failures and potentially extended lifespan.
基金supported by the National Natural Science Foundation of China(82222064,81973147)the National Key Research and Development Program(2022YFC2010100)the Shandong University Distinguished Young Scholars。
文摘Objective Burning solid cooking fuel contributes to household air pollution and is associated with frailty.However,how solid cooking fuel use contributes to the development of frailty has not been well illustrated.Methods This study recruited 8,947 participants aged≥45 years from the China Health and Retirement Longitudinal Study,2011–2018.Group-based trajectory modeling was employed to identify frailty trajectories.Multinomial logistic regression was used to assess the association between solid cooking fuel use and frailty trajectories.Population-attributable fractions were used to estimate the frailty burden from solid fuel use.Results We identified three frailty trajectories:low-stable(n=5,789),moderate-increasing(n=2,603),and fast-increasing(n=555).Solid fuel use was associated with higher odds of being in the moderate-increasing(OR:1.24,95%CI:1.08–1.42)and fast-increasing(OR:1.48,95%CI:1.14–1.92)trajectories.These associations were strengthened by longer solid fuel use(P for trend<0.001).Switching to clean fuel significantly reduced the risk of being in these trajectories compared with persistent solid fuel users.Without solid fuel,8%of moderate-and 19%of fast-increasing trajectories demonstrated frailty development like the low-stable group.Conclusion Solid cooking fuel use is associated with frailty trajectories in middle-aged and older Chinese populations.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(Nos.2022M3J1A1063917 and 2021M3H4A3A02086681).
文摘Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial applications.Among them,methanol is widely used as a hydrogen source,and CO is inevitably generated during its oxidation process.Even a small amount of CO(∼20 ppm)strongly binds to Pt used as a catalyst,and deactivates it.In addition to CO,surface adsorption of organic cations by binder or ionomer use in alkaline fuel cells is also one of the poisoning issues to be overcome.Herein,we propose FePt bimetallic catalysts that can resist unavoidable CO and organic cation poisoning.Our synthetic strategy,including annealing and acid treatment,allows the catalysts to possess different alloying degrees and surface structures,which in turn induce different levels of resistance to CO and organic-cation poisonings.The correlation between the surface and bulk structures of the catalysts and poisoning resistance was elucidated through X-ray photoemission spectroscopy and electrochemical analysis.The results revealed that an FePt catalyst having an ordered atomic arrangement displayed a better poisoning resistance than that having a disordered arrangement.
基金funded by the National Natural Science Foundation of China(Grant No.06101213)the National Natural Science Foundation of China(Grant No.22105160).
文摘3D printing technology enhances the combustion characteristics of hybrid rocket fuels by enabling complex geometries. However, improvements in regression rates and energy properties of monotonous 3D printed fuels have been limited. This study explores the impact of poly(vinylidene fluoride) and polydopamine-coated aluminum particles on the thermal and combustion properties of 3D printed hybrid rocket fuels. Physical self-assembly and anti-solvent methods were employed for constructing composite μAl particles. Characterization using SEM, XRD, XPS, FTIR, and μCT revealed a core-shell structure and homogeneous elemental distribution. Thermal analysis showed that PVDF coatings significantly increased the heat of combustion for aluminum particles, with maximum enhancement observed in μAl@PDA@PVDF(denoted as μAl@PF) at 6.20 k J/g. Subsequently, 3D printed fuels with varying pure and composite μAl particle contents were prepared using 3D printing. Combustion tests indicated higher regression rates for Al@PF/Resin composites compared to pure resin, positively correlating with particle content. The fluorocarbon-alumina reaction during the combustion stage intensified Al particle combustion, reducing residue size. A comprehensive model based on experiments provides insights into the combustion process of PDA and PVDF-coated droplets. This study advances the design of 3D-printed hybrid rocket fuels, offering strategies to improve regression rates and energy release, crucial for enhancing solid fuel performance for hybrid propulsion.
基金National Natural Science Foundation of China,Grant/Award Numbers:52173091,62101391。
文摘Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longrange continuous structure of the nanofiber,ion-charged groups can be induced to form long-range continuous ion transfer channels in the nanofiber composite membrane,significantly increasing the ion conductivity of the membrane.This review stands apart from previous endeavors by offering a comprehensive overview of the strategies employed over the past decade in utilizing both electrospun and natural nanofibers as key components of proton exchange membranes and anion exchange membranes for fuel cells.Electrospun nanofibers are categorized based on their material properties into two primary groups:(1)ionomer nanofibers,inherently endowed with the ability to conduct H+(such as perfluorosulfonic acid or sulfonated poly(ether ether ketone))or OH-(e.g.,FAA-3),and(2)nonionic polymer nanofibers,comprising inert polymers like polyvinylidene difluoride,polytetrafluoroethylene,and polyacrylonitrile.Notably,the latter often necessitates surface modifications to impart ion transport channels,given their inherent proton inertness.Furthermore,this review delves into the recent progress made with three natural nanofibers derived from biodegradable cellulose—cellulose nanocrystals,cellulose nanofibers,and bacterial nanofibers—as crucial elements in polyelectrolyte membranes.The effect of the physical structure of such nanofibers on polyelectrolyte membrane properties is also briefly discussed.Lastly,the review emphasizes the challenges and outlines potential solutions for future research in the field of nanofiber-based polyelectrolyte membranes,aiming to propel the development of high-performance polymer electrolyte fuel cells.
基金Supported by the Major Science and Technology Project of Jilin Province(20220301010GX)the International Scientific and Technological Cooperation(20240402071GH).
文摘The liquid cooling system(LCS)of fuel cells is challenged by significant time delays,model uncertainties,pump and fan coupling,and frequent disturbances,leading to overshoot and control oscillations that degrade temperature regulation performance.To address these challenges,we propose a composite control scheme combining fuzzy logic and a variable-gain generalized supertwisting algorithm(VG-GSTA).Firstly,a one-dimensional(1D)fuzzy logic controler(FLC)for the pump ensures stable coolant flow,while a two-dimensional(2D)FLC for the fan regulates the stack temperature near the reference value.The VG-GSTA is then introduced to eliminate steady-state errors,offering resistance to disturbances and minimizing control oscillations.The equilibrium optimizer is used to fine-tune VG-GSTA parameters.Co-simulation verifies the effectiveness of our method,demonstrating its advantages in terms of disturbance immunity,overshoot suppression,tracking accuracy and response speed.
