Proton Exchange Membrane Water Electrolyzers(PEMWE)are efficient and sustainable hydrogen production devices.This article analyzes their static and dynamic electrical models integrated with degradation mechanisms.Stat...Proton Exchange Membrane Water Electrolyzers(PEMWE)are efficient and sustainable hydrogen production devices.This article analyzes their static and dynamic electrical models integrated with degradation mechanisms.Static models reveal steady-state behavior,while dynamic models capture transient responses to input variations.The developed modeling approach combines the activation and diffusion phenomena,resulting in a novel PEMWE model that closely reflects real-world conditions and enables fast simulations.The electrical model is integrated with the aging model through two key ratios,surface degradation ratio and membrane degradation ratio,which characterize degradation mechanisms affecting electrode and membrane performance.The linear model using second-order Taylor approximation enables the development of a diagnosis approach that can contribute to estimating the remaining useful life of PEMWEs.By associating aging models with electrical models through the proposed ratios,a deeper understanding is achieved regarding how degra-dation phenomena evolve and influence electrolyzer efficiency and durability.The integrated framework enables predictive maintenance strategies,making it valuable for industrial hydrogen production applications.展开更多
Proton exchange membrane(PEM)electrolyzer have attracted increasing attention from the industrial and researchers in recent years due to its excellent hydrogen production performance.Developing accurate models to pred...Proton exchange membrane(PEM)electrolyzer have attracted increasing attention from the industrial and researchers in recent years due to its excellent hydrogen production performance.Developing accurate models to predict their performance is crucial for promoting and accelerating the design and optimization of electrolysis systems.This work developed a Koopman model predictive control(MPC)method incorporating fuzzy compensation for regulating the anode and cathode pressures in a PEM electrolyzer.A PEM electrolyzer is then built to study pressure control and provide experimental data for the identification of the Koopman linear predictor.The identified linear predictors are used to design the Koopman MPC.In addition,the developed fuzzy compensator can effectively solve the Koopman MPC model mismatch problem.The effectiveness of the proposed method is verified through the hydrogen production process in PEM simulation.展开更多
An effective oxygen evolution electrode with Ir0.6Sn0.4O2 was designed for proton exchange membrane(PEM)water electrolyzers.The anode catalyst layer exhibits a jagged structure with smaller particles and pores,which p...An effective oxygen evolution electrode with Ir0.6Sn0.4O2 was designed for proton exchange membrane(PEM)water electrolyzers.The anode catalyst layer exhibits a jagged structure with smaller particles and pores,which provide more active sites and mass transportation channels.The prepared IrSn electrode showed a cell voltage of 1.96 V at 2.0 A cm^-2 with Ir loading as low as 0.294 mg cm^-2.Furthermore,Ir Sn electrode with different anode catalyst loadings was investigated.The IrS n electrode indicates higher mass current and more stable cell voltage than the commercial Ir Black electrode at low loading.展开更多
Amorphous RuO_(x)(a-RuO_(x)) with disordered atomic arrangement and abundant coordinatively unsaturated Ru sites possesses high intrinsic electrocatalytic activity for oxygen evolution reaction (OER).However,the a-RuO...Amorphous RuO_(x)(a-RuO_(x)) with disordered atomic arrangement and abundant coordinatively unsaturated Ru sites possesses high intrinsic electrocatalytic activity for oxygen evolution reaction (OER).However,the a-RuO_(x)is prone to fast corrosion during OER in strong acid.Here we realized the stabilization of an ultrathin a-RuO_(x)layer via constructing heterointerface with crystalline a-MnO_(2)nanorods array (MnO_(2)@aRuO_(x)).Benefiting from the strong electronic interfacial interaction,the as-formed MnO_(2)@a-RuO_(x)electrocatalyst display an ultralow overpotential of 128 mV to reach 10 mA cm^(-2)and stable operation for over 100 h in 0.1 mol L^(-1)HClO_(4).The assembled proton exchange membrane(PEM) water electrolyzer reach 1 A cm^(-2)at applied cell voltage of 1.71 V.Extensive characterizations indicate the MnO_(2)substrate work as an electron donor pool to prevent the overoxidation of Ru sites and the OER proceeds in adsorbent evolution mechanism process without involving lattice oxygen.Our work provides a promising route to construct robust amorphous phase electrocatalysts.展开更多
1.Introduction Hydrogen is an ideal energy carrier to tackle the energy crisis and greenhouse effect,because of its high energy density and low emission.The production,storage and transportation of hydrogen are key fa...1.Introduction Hydrogen is an ideal energy carrier to tackle the energy crisis and greenhouse effect,because of its high energy density and low emission.The production,storage and transportation of hydrogen are key factors to the practical application of hydrogen energy.As the scientific and technological understanding of the electrochemical devices was advancing in the past few decades,water electrolyzers based on the proton exchange membrane (PEM) have attracted much focus for its huge potential on the production of hydrogen via water splitting.PEM electrolyzers use perfluorinated sulfonic acid (PFSA) based membranes as the electrolyte.展开更多
Proton exchange membrane(PEM)electrolyzer(EL)is regarded as a promising technology for hydrogen generation,offering load flexibility for electric grids(EGs),especially those with a high penetration of renewable energy...Proton exchange membrane(PEM)electrolyzer(EL)is regarded as a promising technology for hydrogen generation,offering load flexibility for electric grids(EGs),especially those with a high penetration of renewable energy(RE)sources.This paper proposes a PEM-focused economic dispatch strategy for EG integrated with wind-electrolysis systems.Existing strategies commonly assume a constant efficiency coefficient to model the EL,while the proposed strategy incorporates a bottom-up PEM EL model characterized by a part-load efficiency curve,which accurately represents the nonlinear hydrogen production performance,capturing efficiency variations at different loads.To model this,it first establishes a 0D electrochemical model to derive the polarization curve.Next,it accounts for the hydrogen and oxygen crossover phenomena,represented by the Faraday efficiency,to correct the stack efficiency curve.Finally,it includes the power consumption of ancillary equipment to obtain the nonlinear part-load system efficiency.This strategy is validated using the PJM-5 bus test system with coal-fired generators(CFGs)and is compared with a simple EL model using constant efficiency under three scenarios.The results show that the EL modeling method significantly influences both the dispatch outcome and the economic performance.Sensitivity analyses on coal and hydrogen prices indicate that,for this case study,the proposed strategy is economically advantageous when the coal price is below 121.6$/tonne.Additionally,the difference in total annual operating cost between using the efficiency curve anda constant efficiency to model becomes apparent when the hydrogen price ranges from 2.9 to 5.4$/kg.展开更多
The performance degradation is a crucial factor affecting the commercialization of proton exchange membrane electrolyzer.However,it is difficult to establish a mechanism model incorporating all degradation categories ...The performance degradation is a crucial factor affecting the commercialization of proton exchange membrane electrolyzer.However,it is difficult to establish a mechanism model incorporating all degradation categories due to their different time and spatial scales.In this paper,the data-driven method is employed to predict the electrolyzer voltage variation over time based on a convolutional neural network-long short term memory(CNNLSTM)model.First,two datasets including constant operation for 1140 h and start-stop load for 660 h are collected from the durability tests.Second,the data-driven models are trained through the experimental data and the model hyper-parameters are optimized.Finally,the electrolyzer degradation in the next few hundred hours is predicted,and the prediction accuracy is compared with other time-series algorithms.The results show that the model can predict the degradation precisely on both datasets,with the R2 higher than 0.98.Compared to con-ventional models,the algorithm shows better fitting characteristic to the experimental data,especially as the prediction time increases.For constant and start-stop operations,the electrolyzers degradate by 4.5%and 2.5%respectively after 1000 h.The proposed method shows great potential for real-time monitoring in the electrolyzer system.展开更多
Lowering iridium(Ir)loading without sacrificing activity and durability is critical to the future development of proton exchange membrane water electrolyzer(PEMWE).Here,we present the synthesis of iridate-derived,laye...Lowering iridium(Ir)loading without sacrificing activity and durability is critical to the future development of proton exchange membrane water electrolyzer(PEMWE).Here,we present the synthesis of iridate-derived,layered iridium oxide microparticles(dubbed p-L-IrO_(2))with a high open porosity of approximately 74%and their structural advantages for the fabrication of efficient,durable,low-Ir-loading anode catalytic layer in PEMWE.The p-L-IrO_(2) material is synthesized by an easily scalable route involving acid treatment of alkali metal salt-templated iridates that form in mixed alkali metal nitrateshydroxides at low temperature.The combination of high-porosity morphology and layered structure in the material preferentially exposes a high density of hydroxylated edge sites,which are catalytically active and stable to achieve the oxygen evolution reaction via a structurally hydroxyl group-participated adsorbate evolution mechanism.This material is further demonstrated to enable the fabrication of low-Ir-loading anode catalytic layers in PEMWE,which can afford excellent catalytic performance(2.7 A cm^(−2)@1.9 V@80℃;membrane:Nafion^(TM)N115)due to the simultaneous reduction of activation and mass transport losses and retention of catalytic activity for 2300 h at 1.0 A cm^(−2) current density.展开更多
Maximally exploiting the active sites of iridium catalysts is essential for building low-cost proton exchange membrane(PEM)electrolyzers for green H_(2)production.Herein,we report a novel microdrop-confined fusion/bla...Maximally exploiting the active sites of iridium catalysts is essential for building low-cost proton exchange membrane(PEM)electrolyzers for green H_(2)production.Herein,we report a novel microdrop-confined fusion/blasting(MCFB)strategy for fabricating porous hollow IrO_(1-x)microspheres(IrO_(1-x)-PHM)by introducing explosive gas mediators from a NaNO_(3)/glucose mixture.Moreover,the developed MCFB strategy is demonstrated to be general for synthesizing a series of Ir-based composites,including Ir-Cu,Ir-Ru,Ir-Pt,Ir-Rh,Ir-Pd,and Ir-Cu-Pd and other noble metals such as Rh,Ru,and Pt.The hollow structures can be regulated using different organics with NaNO_(3).The assembled PEM electrolyzer with IrO_(1-x)-PHM as the anode catalyst(0.5 mg/cm^(2))displays an impressive polarization voltage of 1.593and 1.726 V at current densities of 1 and 2 A/cm^(2),respectively,outperforming commercial IrO_(x)catalysts and most of the ever-reported iridium catalysts with such low catalyst loading.More importantly,the breakdown of the polarization loss indicates that the improved performance is due to the facilitated mass transport induced by the hollowness.This study offers a versatile platform for fabricating efficient Irbased catalysts for PEM electrolyzers and beyond.展开更多
文摘Proton Exchange Membrane Water Electrolyzers(PEMWE)are efficient and sustainable hydrogen production devices.This article analyzes their static and dynamic electrical models integrated with degradation mechanisms.Static models reveal steady-state behavior,while dynamic models capture transient responses to input variations.The developed modeling approach combines the activation and diffusion phenomena,resulting in a novel PEMWE model that closely reflects real-world conditions and enables fast simulations.The electrical model is integrated with the aging model through two key ratios,surface degradation ratio and membrane degradation ratio,which characterize degradation mechanisms affecting electrode and membrane performance.The linear model using second-order Taylor approximation enables the development of a diagnosis approach that can contribute to estimating the remaining useful life of PEMWEs.By associating aging models with electrical models through the proposed ratios,a deeper understanding is achieved regarding how degra-dation phenomena evolve and influence electrolyzer efficiency and durability.The integrated framework enables predictive maintenance strategies,making it valuable for industrial hydrogen production applications.
基金supported by 2022 Zhejiang Provincial Science and Technology Plan Project(2022C01035).
文摘Proton exchange membrane(PEM)electrolyzer have attracted increasing attention from the industrial and researchers in recent years due to its excellent hydrogen production performance.Developing accurate models to predict their performance is crucial for promoting and accelerating the design and optimization of electrolysis systems.This work developed a Koopman model predictive control(MPC)method incorporating fuzzy compensation for regulating the anode and cathode pressures in a PEM electrolyzer.A PEM electrolyzer is then built to study pressure control and provide experimental data for the identification of the Koopman linear predictor.The identified linear predictors are used to design the Koopman MPC.In addition,the developed fuzzy compensator can effectively solve the Koopman MPC model mismatch problem.The effectiveness of the proposed method is verified through the hydrogen production process in PEM simulation.
基金financially supported by the National Natural Science Foundation of China(U1664259)State Grid Corporation of China(No.SGTYHT/15-JS-191,PEMWE MEA Preparation and degradation mechanism)
文摘An effective oxygen evolution electrode with Ir0.6Sn0.4O2 was designed for proton exchange membrane(PEM)water electrolyzers.The anode catalyst layer exhibits a jagged structure with smaller particles and pores,which provide more active sites and mass transportation channels.The prepared IrSn electrode showed a cell voltage of 1.96 V at 2.0 A cm^-2 with Ir loading as low as 0.294 mg cm^-2.Furthermore,Ir Sn electrode with different anode catalyst loadings was investigated.The IrS n electrode indicates higher mass current and more stable cell voltage than the commercial Ir Black electrode at low loading.
基金supported by the Fundamental Research Funds for the Central Universities (2232024Y-01)the National Natural Science Foundation of China (52225204, 52272289, 52173233 and 52402231)+3 种基金the Innovation Program of Shanghai Municipal Education Commission (2021-01-07-00-03-E00109)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, Natural Science Foundation of Shanghai (23ZR1479200)“Shuguang Program” supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission (20SG33)the DHU Distinguished Young Professor Program (LZA2022001)。
文摘Amorphous RuO_(x)(a-RuO_(x)) with disordered atomic arrangement and abundant coordinatively unsaturated Ru sites possesses high intrinsic electrocatalytic activity for oxygen evolution reaction (OER).However,the a-RuO_(x)is prone to fast corrosion during OER in strong acid.Here we realized the stabilization of an ultrathin a-RuO_(x)layer via constructing heterointerface with crystalline a-MnO_(2)nanorods array (MnO_(2)@aRuO_(x)).Benefiting from the strong electronic interfacial interaction,the as-formed MnO_(2)@a-RuO_(x)electrocatalyst display an ultralow overpotential of 128 mV to reach 10 mA cm^(-2)and stable operation for over 100 h in 0.1 mol L^(-1)HClO_(4).The assembled proton exchange membrane(PEM) water electrolyzer reach 1 A cm^(-2)at applied cell voltage of 1.71 V.Extensive characterizations indicate the MnO_(2)substrate work as an electron donor pool to prevent the overoxidation of Ru sites and the OER proceeds in adsorbent evolution mechanism process without involving lattice oxygen.Our work provides a promising route to construct robust amorphous phase electrocatalysts.
基金supported by the National Key R&D Program of China(2021YFA1500900,2020YFA0710000)the National Natural Science Foundation of China(22172047,22002039,21825201 and U19A2017)+3 种基金the Provincial Natural Science Foundation of Hunan(2021JJ30089,2016TP1009 and 2020JJ5045)the China Postdoctoral Science Foundation(2019M662759,2020M682541 and 2020M682549)the Shenzhen Science and Technology Program(JCYJ20210324122209025)the Changsha Municipal Natural Science Foundation(kq2107008 and kq2007009)。
文摘1.Introduction Hydrogen is an ideal energy carrier to tackle the energy crisis and greenhouse effect,because of its high energy density and low emission.The production,storage and transportation of hydrogen are key factors to the practical application of hydrogen energy.As the scientific and technological understanding of the electrochemical devices was advancing in the past few decades,water electrolyzers based on the proton exchange membrane (PEM) have attracted much focus for its huge potential on the production of hydrogen via water splitting.PEM electrolyzers use perfluorinated sulfonic acid (PFSA) based membranes as the electrolyte.
基金supported by National Key R&D Program of China(Grant No.2021YFE0191200)which has received funding from Ministry of Science and Technology of the People’s Republic of China.
文摘Proton exchange membrane(PEM)electrolyzer(EL)is regarded as a promising technology for hydrogen generation,offering load flexibility for electric grids(EGs),especially those with a high penetration of renewable energy(RE)sources.This paper proposes a PEM-focused economic dispatch strategy for EG integrated with wind-electrolysis systems.Existing strategies commonly assume a constant efficiency coefficient to model the EL,while the proposed strategy incorporates a bottom-up PEM EL model characterized by a part-load efficiency curve,which accurately represents the nonlinear hydrogen production performance,capturing efficiency variations at different loads.To model this,it first establishes a 0D electrochemical model to derive the polarization curve.Next,it accounts for the hydrogen and oxygen crossover phenomena,represented by the Faraday efficiency,to correct the stack efficiency curve.Finally,it includes the power consumption of ancillary equipment to obtain the nonlinear part-load system efficiency.This strategy is validated using the PJM-5 bus test system with coal-fired generators(CFGs)and is compared with a simple EL model using constant efficiency under three scenarios.The results show that the EL modeling method significantly influences both the dispatch outcome and the economic performance.Sensitivity analyses on coal and hydrogen prices indicate that,for this case study,the proposed strategy is economically advantageous when the coal price is below 121.6$/tonne.Additionally,the difference in total annual operating cost between using the efficiency curve anda constant efficiency to model becomes apparent when the hydrogen price ranges from 2.9 to 5.4$/kg.
基金financial supports of National Key Research and Development Program of China(No.2021YFB4000100)National Natural Science Foundation of China(No.52322604).
文摘The performance degradation is a crucial factor affecting the commercialization of proton exchange membrane electrolyzer.However,it is difficult to establish a mechanism model incorporating all degradation categories due to their different time and spatial scales.In this paper,the data-driven method is employed to predict the electrolyzer voltage variation over time based on a convolutional neural network-long short term memory(CNNLSTM)model.First,two datasets including constant operation for 1140 h and start-stop load for 660 h are collected from the durability tests.Second,the data-driven models are trained through the experimental data and the model hyper-parameters are optimized.Finally,the electrolyzer degradation in the next few hundred hours is predicted,and the prediction accuracy is compared with other time-series algorithms.The results show that the model can predict the degradation precisely on both datasets,with the R2 higher than 0.98.Compared to con-ventional models,the algorithm shows better fitting characteristic to the experimental data,especially as the prediction time increases.For constant and start-stop operations,the electrolyzers degradate by 4.5%and 2.5%respectively after 1000 h.The proposed method shows great potential for real-time monitoring in the electrolyzer system.
基金support from the National Key R&D Program of China(grant no.2021YFB4000200)the National Natural Science Foundation of China(grant nos.22279040,22179046,and 22205072)+4 种基金the State Grid Headquarters Science and Technology project(grant no.5419-202158490A-0-5-ZN)the China Postdoctoral Science Foundation(grant no.2021M701377),the Fundamental Research Funds for the Central Universitiesthe Science and Technology Research Program of Education Department of Jilin Province(grant no.JJKH20231162KJ)the Jilin Province Science and Technology Development Plan(grant no.20220402006GH)We also thank the 111 Project(grant no.B17020)for additional financial support.PDF was performed at the Brockhouse Diffraction Sector beamlines of the Canadian Light Source(CLS),a national research facility of the University of Saskatchewan.Authors thank the CLS for providing the beamtime.
文摘Lowering iridium(Ir)loading without sacrificing activity and durability is critical to the future development of proton exchange membrane water electrolyzer(PEMWE).Here,we present the synthesis of iridate-derived,layered iridium oxide microparticles(dubbed p-L-IrO_(2))with a high open porosity of approximately 74%and their structural advantages for the fabrication of efficient,durable,low-Ir-loading anode catalytic layer in PEMWE.The p-L-IrO_(2) material is synthesized by an easily scalable route involving acid treatment of alkali metal salt-templated iridates that form in mixed alkali metal nitrateshydroxides at low temperature.The combination of high-porosity morphology and layered structure in the material preferentially exposes a high density of hydroxylated edge sites,which are catalytically active and stable to achieve the oxygen evolution reaction via a structurally hydroxyl group-participated adsorbate evolution mechanism.This material is further demonstrated to enable the fabrication of low-Ir-loading anode catalytic layers in PEMWE,which can afford excellent catalytic performance(2.7 A cm^(−2)@1.9 V@80℃;membrane:Nafion^(TM)N115)due to the simultaneous reduction of activation and mass transport losses and retention of catalytic activity for 2300 h at 1.0 A cm^(−2) current density.
基金supported by the National Natural Science Foundation of China(22375004,22175163,and 21801003)Anhui Provincial Education Department(2023AH020014,2023AH010030,gxgnfx2021132)+5 种基金the University Synergy Innovation Program of Anhui Province(GXXT-2022-007)Science and Technology Program of Wuhu(2022yf60)the Natural Science Foundation of Anhui Province(2208085UD04)the Plan for Anhui Major Provincial Science&Technology Project(2021d05050006 and 202103a05020015)the Anhui Development and Reform Commission(AHZDCYCX-LSDT2023-07 and AHZDCYCX-LSDT2023-08)Anhui Polytechnic University(Youth Talent Training Program(2021))。
文摘Maximally exploiting the active sites of iridium catalysts is essential for building low-cost proton exchange membrane(PEM)electrolyzers for green H_(2)production.Herein,we report a novel microdrop-confined fusion/blasting(MCFB)strategy for fabricating porous hollow IrO_(1-x)microspheres(IrO_(1-x)-PHM)by introducing explosive gas mediators from a NaNO_(3)/glucose mixture.Moreover,the developed MCFB strategy is demonstrated to be general for synthesizing a series of Ir-based composites,including Ir-Cu,Ir-Ru,Ir-Pt,Ir-Rh,Ir-Pd,and Ir-Cu-Pd and other noble metals such as Rh,Ru,and Pt.The hollow structures can be regulated using different organics with NaNO_(3).The assembled PEM electrolyzer with IrO_(1-x)-PHM as the anode catalyst(0.5 mg/cm^(2))displays an impressive polarization voltage of 1.593and 1.726 V at current densities of 1 and 2 A/cm^(2),respectively,outperforming commercial IrO_(x)catalysts and most of the ever-reported iridium catalysts with such low catalyst loading.More importantly,the breakdown of the polarization loss indicates that the improved performance is due to the facilitated mass transport induced by the hollowness.This study offers a versatile platform for fabricating efficient Irbased catalysts for PEM electrolyzers and beyond.
