Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkali...Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkaline operating conditions has proven challenging.To address this challenge,we develop a pre-concentration regulated phase separation strategy for scalable fabrication of asymmetric hierarchical porous membranes(AHPMs)for AWE.The resulting AHPMs demonstrate a hierarchical structure composed of an ultrathin dense skin layer and highly interconnected porous support.Benefitting from the structural advantages,the AHPMs exhibit outstanding characteristics,including a high bubble point pressure up to 12.4 bar,extremely low area resistance of 0.03Ωcm^(2) in 30 wt%KOH at 80℃,and excellent hydrophilicity and long-term alkaline stability.When applied in AWE with commercial catalysts,the AHPMs achieved an impressive current density of 1.9 A cm^(-2) at 2.0 V in 30 wt%KOH and the anodic hydrogen contents(AHCs)below 0.5 vol.%at a low current density of 0.1 A cm^(-2),differential pressure of 2 bar,and temperature of 80℃.Moreover,AHPMs demonstrate exceptional stability over 2,400 h of continuous operation and maintain superior performance in a 1 Nm^(3) h^(-1) industrialscale electrolyzer stack.This work advances the development of efficient separators for highperformance AWE systems,contributing to the advancement of hydrogen technologies in sustainable energy applications.展开更多
Pulsed dynamic electrolysis(PDE),driven by renewable energy,has emerged as an innovative electrocatalytic conversion method,demonstrating significant potential in addressing global energy challenges and promoting sust...Pulsed dynamic electrolysis(PDE),driven by renewable energy,has emerged as an innovative electrocatalytic conversion method,demonstrating significant potential in addressing global energy challenges and promoting sustainable development.Despite significant progress in various electrochemical systems,the regulatory mechanisms of PDE in energy and mass transfer and the lifespan extension of electrolysis systems,particularly in water electrolysis(WE)for hydrogen production,remain insufficiently explored.Therefore,there is an urgent need for a deeper understanding of the unique contributions of PDE in mass transfer enhancement,microenvironment regulation,and hydrogen production optimization,aiming to achieve low-energy consumption,high catalytic activity,and long-term stability in the generation of target products.Here,this review critically examines the microenvironmental effects of PDE on energy and mass transfer,the electrode degradation mechanisms in the lifespan extension of electrolysis systems,and the key factors in enhancing WE for hydrogen production,providing a comprehensive summary of current research progress.The review focuses on the complex regulatory mechanisms of frequency,duty cycle,amplitude,and other factors in hydrogen evolution reaction(HER)performance within PDE strategies,revealing the interrelationships among them.Finally,the potential future directions and challenges for transitioning from laboratory studies to industrial applications are proposed.展开更多
Membra ne electrode assemblies(MEAs)are pivotal to advancing proton exchange membra ne water electrolysis(PEMWE),yet conventional designs suffer from limited triple-phase boundaries(TPBs),inefficient mass/charge trans...Membra ne electrode assemblies(MEAs)are pivotal to advancing proton exchange membra ne water electrolysis(PEMWE),yet conventional designs suffer from limited triple-phase boundaries(TPBs),inefficient mass/charge transport,and insufficient durability.This study introduces a three-dimensional ordered pattern-array(3D OPA)architecture fabricated via a scalable laser-machined mask and hot-pressing strategy.The 3D OPA MEA achieves a current density of 3.73 A cm^(-2) at 2 V,demonstrating a 50%performance improvement over the conventional MEA(2.48 A cm^(-2)),alongside a degradation rate of 26.6μV h^(-1) in a highly dynamic accelerated stress test(AST).Additionally,numerical simulations corroborate that the OPA architecture optimizes localized oxygen diffusion and liquid water replenishment,enhancing reaction kinetics.The 3D OPA architecture enhances TPBs and establishes optimized gas-liquid tra nsport pathways,significantly improving catalyst utilization while minimizing mass transfer overpotential and bubble-induced losses.Furthermore,its interlocking design reinforces mechanical interactions,reducing ohmic resistance a nd ensuring sustained mecha nical integrity and electrochemical durability.This work provides a simple,cost-effective,and scalable approach for patterned MEAs,addressing critical barriers to PEMWE commercialization through rational TPB engineering and transport pathway optimization.展开更多
Developing practical anion exchange membrane water electrolysis(AEMWE)technology encounters great challenges in not only cell efficiency but also long-term durability due to mechanical electrocatalyst detachment and e...Developing practical anion exchange membrane water electrolysis(AEMWE)technology encounters great challenges in not only cell efficiency but also long-term durability due to mechanical electrocatalyst detachment and electrochemical dissolution of active species,especially for the anodic oxygen evolution reaction(OER).Herein,a"two-pronged"approach is proposed to construct organophosphorus-protected NiFe layered double hydroxide catalysts on plasma-modified substrate,serving as an efficient and robust anode for practical AEMWE.Mechanical tests combined with operando spectroscopies and theoretical calculations demonstrate that the plasma modification strengthens the catalyst-substrate adhesion,while the organophosphorus protection prevents Fe leaching and promotes reaction kinetics during OER.The resultant electrode delivers an ultralow overpotential of 276 mV at 1 A cm^(-2),together with a remarkable stability at 0.5 A cm^(-2)over 500 h.Furthermore,assembling the optimized anode into an AEMWE device contributes to a minimized cell voltage of 1.70 V at 1 A cm^(-2),which sustains durable green hydrogen production with an economical energy consumption of 4.16 kW h Nm^(-3)H_(2).展开更多
Valence state engineering has emerged as a powerful strategy to optimize catalytic performance by modulating the electronic structure of metal active sites.However,the valence state regulation in high-entropy compound...Valence state engineering has emerged as a powerful strategy to optimize catalytic performance by modulating the electronic structure of metal active sites.However,the valence state regulation in high-entropy compounds(HECs)remains elusive due to their complex multi-element components and electronic interactions.Here,the valence states of different metals in twodimensional(2D)high entropy oxide(HEO)(FeNiMoRuV)O_(2-x)are precisely modulated through controlled pyrolysis of corresponding 2D high entropy hydroxide(HEHO)(FeNiMoRuV)(OH)_(2)under varying temperatures.Temperature-controlled pyrolysis selectively reduces the oxidation state of Ru,while simultaneously increasing the valence state of other constituent metals(Fe,Ni,Mo,and V),suggesting a competitive redox equilibrium.Notably,these low-valence Ru sites with oxygen vacancy in 2D HEO significantly reduce Ru-O bond energy and promote the generation of O-^(O)intermediates,thereby enabling oxygen evolution with a lattice oxygen mediated-oxygen vacancy site mechanism.2D HEO with low-valence Ru exhibits superior electrolytic water performance(HER/OER)compared to HEHO and other HEO with high-valence Ru,achieving a current density of 1000 mA cm^(-2)at 1.923 V,which exceeds the commercial Pt/C‖RuO_(2)system.Therefore,this study reveals the valence state regulatory mechanism of HECs and provides a solid hammer for the catalytic mechanism of valence state engineering.展开更多
Seawater electrolysis for hydrogen production faces inherent challenges, including side reactions, corrosion, and scaling, stemming from the intricate composition of seawater. In response, researchers have turned to c...Seawater electrolysis for hydrogen production faces inherent challenges, including side reactions, corrosion, and scaling, stemming from the intricate composition of seawater. In response, researchers have turned to continuous water splitting using forward osmosis(FO)-driven seawater desalination. However, the necessity of a neutral electrolyte hampers this strategy due to the limited current density and scarcity of precious metals. Herein, this study applies alkali-durable FO membranes to enable self-sustaining seawater splitting, which can selectively withdraw water molecules, from seawater, via concentration gradient. The membranes demonstrates outstanding perm-selectivity of water/ions(~5830 mol mol^(-1)) during month-long alkaline resistance tests, preventing electrolyte leaching(>97% OHàretention) while maintaining ~95%water balance(V_(FO)= V_(electrolysis)) via preserved concentration gradient for consistent forward-osmosis influx of water molecules. With the consistent electrolyte environment protected by the polyamide FO membranes, the Ni Fe-Ar-P catalyst exhibits promising performance: a sustain current density of 360 m A cmà2maintained at the cell voltage of 2.10 V and 2.15 V for 360 h in the offshore seawater, preventing Cl/Br corrosion(98% rejection) and Mg/Ca passivation(99.6% rejection). This research marks a significant advancement towards efficient and durable seawater-based hydrogen production.展开更多
Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various ele...Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various electrolysis technologies,the emerging anion exchange membrane water electrolyser(AEMWE)exhibits the most potential for green hydrogen production,offering a potentially costeffective and sustainable approach that combines the advantages of high current density and fast start from proton exchange membrane water electrolyser(PEMWE)and low-cost catalyst from traditional alkaline water electrolyser(AWE)systems.Due to its relatively recent emergence over the past decade,a series of efforts are dedicated to improving the electrochemical reaction performance to accelerate the development and commercialization of AEMWE technology.A catalytic electrode comprising a gas diffusion layer(GDL)and a catalyst layer(CL)is usually called a gas diffusion electrode(GDE)that serves as a fundamental component within AEMWE,and also plays a core role in enhancing mass transfer during the electrolysis process.Inside the GDEs,bubbles nucleate and grow within the CL and then are transported through the GDL before eventually detaching to enter the electrolyte in the flow field.The transfer processes of water,gas bubbles,charges,and ions are intricately influenced by bubbles.This phenomenon is referred to as bubble-associated mass transfer.Like water management in fuel cells,effective bubble management is crucial in electrolysers,as its failure can result in various overpotential losses,such as activation losses,ohmic losses,and mass transfer losses,ultimately degrading the AEMWE performance.Despite significant advancements in the development of new materials and techniques in AEMWE,there is an urgent need for a comprehensive discussion focused on GDEs,with a particular emphasis on bubbleassociated mass transfer phenomena.This review aims to highlight recent findings regarding mass transfer in GDEs,particularly the impacts of bubble accumulation;and presents the latest advancements in designing CLs and GDLs to mitigate bubble-related issues.It is worth noting that a series of innovative bubble-free-GDE designs for water electrolysis are also emphasized in this review.This review is expected to be a valuable reference for gaining a deeper understanding of bubble-related mass transfer,especially the complex bubble behavior associated with GDEs,and for developing innovative practical strategies to advance AEMWE for green hydrogen production.展开更多
Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct c...Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct conditions required for oxygen and hydrogen evolution reaction(OER and HER).Herein,we propose a theory-directed design of Ir-based bifunctional catalysts,Ir nanoparticles supported on mesoporous carbon spheres embedded with MoSe_(2)(Ir/MoSe_(2)@MCS),leveraging a work function(WF)-induced spontaneous built-in electric field to enhance catalytic performance.They demonstrate exceptional kinetics for both OER and HER,and potential application in the practical PEM electrolyzer,showcasing the effectiveness of this innovative approach.Low overpotentials of 252 mV for OER and 28 mV for HER to drive 10 mA cm^(-2)were observed,and the PEM electrolyzer showed the current density of 2 A cm^(-2)at 1.87 V and maintained stable activity at 1.65 V for over 30 h to deliver 1 A cm^(-2).Density functional theory calculations reveal that the WF difference at Ir/MoSe_(2)interface induces a spontaneous built-in electric field with asymmetric charge distributions,that modulate the electronic environment and d-band center of Ir promoting bifunctional active phase formation.This significantly lowers reaction barriers for water splitting by balancing intermediate adsorption,endowing the bifunctional activity.展开更多
Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojuncti...Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojunction catalyst confined in carbon nanofiber with spontaneous charge redistribution driven by high valent metal,which promotes the adsorption and transformation of intermediates and greatly reduces the reaction energy barrier for urea oxidation.The heterojunction catalyst promotes the formation of Ni^(3+)active species and accelerates the fracture of the C-N bond by enhancing selective adsorption of-NH_(2)and C=O groups in binding urea molecules driven by the spontaneous formation of nucleophilic and electrophilic sites.The catalyst achieves a low kinetic current density of 10 mA cm^(-2)at 1.35 V with a cell voltage for urea electrolysis of just 1.47 V and good durability over 60 h.Density-functional theory and in-situ spectral observation reveal that the high valent Mo promoted the 3d orbit of Ni approaching the Fermi level by adjusting the electronic structure,which enhanced spontaneous urea dehydrogenation and reduced the energy barrier for^(*)COO desorption.This study highlights the effectiveness of modulating the interfacial electronic structure to improve energy conversion efficiency.展开更多
Hydrogen energy, as one of the cleanest energy sources, has emerged as a leading candidate for replacing nonrenewable energy. However, hydrogen is not directly available from nature. Challenges such as high production...Hydrogen energy, as one of the cleanest energy sources, has emerged as a leading candidate for replacing nonrenewable energy. However, hydrogen is not directly available from nature. Challenges such as high production costs and the need for efficient large-scale production technologies remain significant obstacles. Among the various hydrogen production methods, water electrolysis stands out due to its environmentally friendly nature and the high purity of hydrogen produced. Proton exchange membrane(PEM) electrolyzers are promising devices for hydrogen production. They exhibit the superiorities in high operational current densities exceeding 2 A cm^(-2), greater resistance to fluctuations, and improved electrolysis efficiency. A critical component of PEM water electrolyzers is the porous transport layer(PTL), which serves as an electron conductor between the membrane electrode assembly and the bipolar plate, ensuring efficient mass transport between gas and liquid phases. This review provides a comprehensive examination of PTL materials,structural configurations, surface treatments, and the resulting performance of electrolytic cells. These insights aim to guide researchers in selecting appropriate PTL materials and treatments tailored to specific practical applications. Additionally, this paper analyzes operational conditions—such as compaction pressure, temperature,water flow rate, and oxygen saturation within the electrolyzer—that influence PTL performance. These factors are crucial for researchers to holistically design and optimize PEM electrolyzer systems.展开更多
Integrating electrochemical upgrading of glycerol and water electrolysis is regarded as a promising and energy-saving approach for the co-production of chemicals and hydrogen.However,developing efficient electrocataly...Integrating electrochemical upgrading of glycerol and water electrolysis is regarded as a promising and energy-saving approach for the co-production of chemicals and hydrogen.However,developing efficient electrocatalyst towards this technology remains challenging.Herein,a metallic cobalt mediated molybdenum nitride heterostructural material has been exploited on nickel foam(Co@Mo_(2)N/NF)for the glycerol oxidation reaction(GOR)and hydrogen evolution reaction(HER).Remarkably,the obtained Co@Mo_(2)N/NF realizes eminent performance with low overpotential of 49 mV at 50 mA/cm^(2)for HER and high Faradaic efficiency of formate of 95.03%at 1.35 V vs.RHE for GOR,respectively.The systematic in-situ experiments reveal that the Co@Mo_(2)N heterostructure promotes the cleavage of C-C bond in glycerol by active CoOOH species and boosts the conversion of glycerol to aldehyde intermediates to formate product.Moreover,the density functional theory(DFT)calculations confirm the strong interaction at Co@Mo_(2)N interface,which contributes to the optimized water dissociation and the transformation of H^(*)to H^(2).Benefiting from those advantages,the built HER||GOR electrolyzer delivers a low voltage of 1.61 V at 50 mA/cm^(2),high Faradaic efficiency,and robust stability over 120 h for sustained and stable electrolysis.展开更多
Urgent requirements of the renewable energy boost the development of stable and clean hydrogen,which could effectively displace fossil fuels in mitigating climate changes.The efficient interconversion of hydrogen and ...Urgent requirements of the renewable energy boost the development of stable and clean hydrogen,which could effectively displace fossil fuels in mitigating climate changes.The efficient interconversion of hydrogen and electronic is highly based on polymer electrolyte membrane fuel cells(PEMFCs)and water electrolysis(PEMWEs).However,the high cost continues to impede large-scale commercialization of both PEMFC and PEMWE technologies,with the expense primarily attributed to noble catalysts serving as a major bottleneck.The reduction of Pt loading in PEMFCs is essential but limited by the oxygen transport resistance in the cathode catalyst layers(CCLs),while the oxygen transport in anode catalyst layers(ACLs)in PEMWEs also being focused as the Ir/IrO_(x) catalyst reduced.The pore structure and the catalyst-ionomer agglomerates play important roles in the oxygen transport process of both PEMFCs and PEMWEs due to the similarity of membrane electrode assembly(MEA).Herein,the oxygen transport mechanism of PEMFCs in pore structure and ionomer thin films in CCLs is systematically reviewed,while state-of-the-art strategies are presented for enhancing oxygen transport and performance through materials and structural design.The deeply research opens avenues for exploring similar key scientific problems in oxygen transport process of PEMWEs and their further development.展开更多
The global drive for sustainable energy solutions intensified interest in anion exchange membrane water electrolysis(AEMWE),as a promising hydrogen production pathway,leveraging renewable energy sources.However,widesp...The global drive for sustainable energy solutions intensified interest in anion exchange membrane water electrolysis(AEMWE),as a promising hydrogen production pathway,leveraging renewable energy sources.However,widespread adoption is hindered by the high cost and non-optimised design of crucial components,such as porous transport layers(PTL)and flow fields.This study comprehensively investigates the interplay between structure,mechanics,and electrochemical performance of a low-cost knitted wire mesh PTL,focusing on its potential to enhance cell assembly and operation.Electrochemical characterisation was performed on a single 4 cm^(2)cell,using 1M KOH at 60℃.Knitted wire mesh PTL,characterised by approximately 70%porosity,2mm thickness,and 1.098 tortuosity,delivered a 33%improvement in current density compared to the standard cell configuration.Introducing a knitted PTL interlayer reduced cell voltage by 74 mV at 2 A cm^(−2)by improving compression force distribution across the active area,enhancing gas transport and maintaining optimal electrical and thermal conductivity.These findings highlight the significant potential of innovative PTL designs in AEMWE to improve mechanical and operational efficiency without increasing the cost.展开更多
The commercialization of proton exchange membrane water electrolysis(PEMWE)for green hydrogen production hinges on the development of low-cost,high-performance titanium porous transport layers(PTLs).This study introdu...The commercialization of proton exchange membrane water electrolysis(PEMWE)for green hydrogen production hinges on the development of low-cost,high-performance titanium porous transport layers(PTLs).This study introduces a triple-layer Ti-PTL with a graded porous structure and a 75%ultra-high porosity backing layer,fabricated through tape casting and roll calendering.This triple-layer PTL,composed of a microporous layer,an interlayer,and a highly porous backing layer,enhances catalyst utilization,mechanical integrity,and mass transport.Digital twin technology using X-ray revealed increased contact area and triple-phase boundary at the interface with the catalyst layer,significantly improving oxygen evolution reaction kinetics.Numerical simulations demonstrated that the strategically designed porous structure of the triple-layer PTL facilitates efficient oxygen transport,mitigates oxygen accumulation,and improves reactant accessibility.Electrochemical evaluations showed improved performance,achieving 127 mV reduction in voltage at 2 A cm^(-2)compared to a commercial PTL,highlighting its potential to enhance PEMWE efficiency and cost-effectiveness.展开更多
Anion exchange membrane water electrolysis(AEMWE)synergize the kinetic merits of alkaline systems,zero-gap configurations and compatibility with non-noble metal catalysts,offering a promising pathway toward green hydr...Anion exchange membrane water electrolysis(AEMWE)synergize the kinetic merits of alkaline systems,zero-gap configurations and compatibility with non-noble metal catalysts,offering a promising pathway toward green hydrogen production.Nevertheless,practical exploitation was hindered by critical challenges:inferior alkaline stability,insufficient mechanical integrity,and detrimental hydrogen crossover of anion exchange membranes(AEMs),which compromise both device durability and operational safety.Here,we engineered a porous expanded polytetrafluoroethylene(e-PTFE)-reinforced poly(arylene quinuclidinium)membrane that enhances AEM mechanical robustness,prevents stress-induced rupture,and suppresses hydrogen crossover during electrolyzer operation.Specifically,the reinforced poly(arylene quinuclidinium)membrane(R-PTPQui)exhibited a tensile strength of 56 MPa and an elongation at break of 55%.Moreover,it effectively reduced hydrogen permeation in the electrolyzer,achieving an extremely low H_(2)-to-O_(2)(HTO)value of 0.44 vol%at 0.1 A·cm^(-2).The R-PTPQui-based electrolyzer achieved a high current density of 4.9 A·cm^(-2)at 2.0 V and a Faradaic efficiency of 98.6%using a non-precious anode catalyst.These advances significantly strength the compatibility of poly(arylene quinuclidinium)-based AEMs for industrial-scale green hydrogen generation.展开更多
Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a signific...Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a significant challenge.Herein,we report a vacancy occupation-triggered phase transition strategy to fabricate a core-shell 1T phase nanorod structure,which is composed of S-vacancies decorated MoS_(2)as the core,and N,P co-doped carbons as the shell(1T-MoS_(2)@NPC).The co-insertion of N and P dopants into MoS_(2)can occupy partial S-vacancies,triggering a phase transformation from the semiconducting 2H phase to the conducting 1T phase with a reduced energy barrier.Profiting from the strong coupling effect between N,P dopants and S-vacancies,the as-made 1T-MoS_(2)@NPC exhibits excellent electrocatalytic activity for both HER(η_(10)=148 m V)and OER(η_(10)=232 mV)in alkaline solution.Meanwhile,a low cell voltage of 1.62 V is needed to drive a current density of 10mA cm^(-2)in 1.0 M KOH electrolyte.The theoretical calculation results reveal that the S-vacancies decorated C atoms in the meta-position relative to N,P atoms represent the most active HER and OER sites,which synergistically upshift the d band center and balance the rate-determining step,thus ensuring the simultaneous optimization of adsorption free energy and electronic structure.This vacancy-occupation-derived phase transformation strategy caused by non-metallic doping may provide valuable guidance for enhancing the performance of alkaline water electrolysis.展开更多
Since the beginning of the 20th century,alkaline electrolysis has been used as a proven method for producing hydrogen on a megawatt scale.The existence of parasitic shunt currents in alkaline water electrolysis,which ...Since the beginning of the 20th century,alkaline electrolysis has been used as a proven method for producing hydrogen on a megawatt scale.The existence of parasitic shunt currents in alkaline water electrolysis,which is utilized to produce clean hydrogen,is investigated in this work.Analysis has been done on a 20-cell stack.Steel end plates,bipolar plates,and an electrolyte concentration of 6 M potassium hydroxide are all included in the model.The Butler-Volmer kinetics equations are used to simulate the electrode surfaces.Ohmic losses are taken into consideration in both the electrode and electrolyte phases,although mass transport constraints in the gas phase are not.Using an auxiliary sweep to solve equations,the model maintains an isothermal condition at 85℃ while adjusting the average cell voltage between 1.3 and 1.8 V.The results show that lower shunt currents in the outlet channels as opposed to the intake channels are the result of the electrolyte’s lower effective conductivity in the upper channels,which is brought on by a lower volume fraction of the electrolyte.Additionally,it has been seen that the shunt currents intensify as the stack gets closer to the conclusion.Efficiency is calculated by dividing the maximum energy output(per unit of time)that a fuel cell operating under comparable conditions might produce by the electrical energy needed to generate that output inside the stack.At first,energy efficiency increases due to the rise in coulombic efficiency,peaking around 1400 mA.The subsequent decline after reaching 1400 mA is linked to an increase in stack voltage at elevated current levels.展开更多
Despite the cost and activity advantages,ruthenium-based oxygen evolution reaction(OER)catalysts face severe stability problems for proton exchange membrane water electrolysis(PEM-WE)due to Ru dissolution.Although tre...Despite the cost and activity advantages,ruthenium-based oxygen evolution reaction(OER)catalysts face severe stability problems for proton exchange membrane water electrolysis(PEM-WE)due to Ru dissolution.Although tremendous attention has been paid to enhancing the stability and activity under small current density in three electrode systems,there still lacks validation under industrial current density at the device level.Aiming at this issue,we report highly active and durable ruthenium-iridium alloyed oxides(IrRuO_(x))as the acidic OER catalyst for PEM-WE with exceptional durability for 1600 h at an industrial current density of 2.0 A·cm^(−2).X-ray absorption spectroscopy reveals that the introduction of iridium modulates the electronic structure of Ru and strengthens the local Ru–O bonds in RuO_(2),which is crucial for ensuring activity and stability.As a result,in comparison with its RuO_(2) counterpart,IrRuO_(x) works stably against the Ru leaching-induced catalytic layer breakage during the stability test.This work demonstrates the great potential of IrRuO_(x) as the practical OER catalyst for the application in PEM-WE.展开更多
In alkaline water electrolysis(AWE),the development of high-performance membranes with excellent ionic conductivity,robust mechanical stability,and superior gas barrier properties is crucial for efficient hydrogen ene...In alkaline water electrolysis(AWE),the development of high-performance membranes with excellent ionic conductivity,robust mechanical stability,and superior gas barrier properties is crucial for efficient hydrogen energy conversion.This study proposes a superhydrophilic composite membrane based on a synergistic hydrogen bonding and coordination strategy for structural regulation and performance enhancement in AWE.During the non-solvent-induced phase separation(NIPS)process,polyvinylpyrrolidone(PVP)and tannic acid(TA)form a stable hydrogen-bonded network in the water coagulation bath,effectively inducing the construction of a hierarchical porous structure with coexisting finger-like and sponge-like pores.This design enables efficient OH^(-)transport while significantly improving gas barrier properties.On this basis,coordination between TA and ZrO_(2) particles further establishes an organicinorganic micro-interlocking structure,enhancing structural stability and interfacial continuity of the membrane.The optimized PTP3 composite membrane exhibits outstanding comprehensive properties,including high tensile strength(38.77 MPa),elevated bubble point pressure(4.27 bar),and low area resistance(0.12Ωcm^(2)),achieving a current density of 779 mA cm^(-2)at 2 V.In addition,the membrane maintains excellent structural integrity and performance stability after continuous operation for 300 h in a high-temperature,strongly alkaline environment,with negligible degradation.This study offers a novel interfacial hydrogen bonding-coordination design strategy for the development of high-performance,energy-efficient AWE membranes,providing a solid foundation for improving hydrogen production efficiency and enabling large-scale alkaline electrolysis applications.展开更多
Proton exchange membrane water electrolysis(PEMWE)has emerged as a promising technology for hydrogen production,offering high efficiency,superior hydrogen purity,and a compact system design.However,its widespread adop...Proton exchange membrane water electrolysis(PEMWE)has emerged as a promising technology for hydrogen production,offering high efficiency,superior hydrogen purity,and a compact system design.However,its widespread adoption is hindered by the harsh acidic environment and the intrinsically slow kinetics of the oxygen evolution reaction(OER)at the anode.Addressing these challenges requires the development of robust,acidresistant anode catalysts.Among various candidates,iridium-based catalysts(IBCs)have attracted significant attention owing to their exceptional catalytic activity and stability under acidic conditions.Nevertheless,the high cost and limited availability of Ir impede their large-scale application.To mitigate these issues,extensive research has been devoted to strategies that reduce Ir loading while enhancing catalytic performance.This review provides a comprehensive and systematic overview of recent advances in the rational design of IBCs,focusing on strategies such as multi-scale morphology control,heteroatom doping,alloying,defect engineering,heterostructure construction,and support interactions.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52273059 and 52473219)the Natural Science Foundation of Tianjin(Grant Nos.22JCYBJC01030 and 23JCYBJC00650)provided by Yantai Tayho Advanced Materials Group Co.,Ltd.
文摘Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkaline operating conditions has proven challenging.To address this challenge,we develop a pre-concentration regulated phase separation strategy for scalable fabrication of asymmetric hierarchical porous membranes(AHPMs)for AWE.The resulting AHPMs demonstrate a hierarchical structure composed of an ultrathin dense skin layer and highly interconnected porous support.Benefitting from the structural advantages,the AHPMs exhibit outstanding characteristics,including a high bubble point pressure up to 12.4 bar,extremely low area resistance of 0.03Ωcm^(2) in 30 wt%KOH at 80℃,and excellent hydrophilicity and long-term alkaline stability.When applied in AWE with commercial catalysts,the AHPMs achieved an impressive current density of 1.9 A cm^(-2) at 2.0 V in 30 wt%KOH and the anodic hydrogen contents(AHCs)below 0.5 vol.%at a low current density of 0.1 A cm^(-2),differential pressure of 2 bar,and temperature of 80℃.Moreover,AHPMs demonstrate exceptional stability over 2,400 h of continuous operation and maintain superior performance in a 1 Nm^(3) h^(-1) industrialscale electrolyzer stack.This work advances the development of efficient separators for highperformance AWE systems,contributing to the advancement of hydrogen technologies in sustainable energy applications.
基金financially supported by the Key Research and Development Program of Heilongjiang Province(No.2024ZXJ03C06)National Natural Science Foundation of China(No.52476192,No.52106237)+1 种基金Natural Science Foundation of Heilongjiang Province(No.YQ2022E027)Technology Project of China Datang Technology Innovation Co.,Ltd(No.DTKC-2024-20610).
文摘Pulsed dynamic electrolysis(PDE),driven by renewable energy,has emerged as an innovative electrocatalytic conversion method,demonstrating significant potential in addressing global energy challenges and promoting sustainable development.Despite significant progress in various electrochemical systems,the regulatory mechanisms of PDE in energy and mass transfer and the lifespan extension of electrolysis systems,particularly in water electrolysis(WE)for hydrogen production,remain insufficiently explored.Therefore,there is an urgent need for a deeper understanding of the unique contributions of PDE in mass transfer enhancement,microenvironment regulation,and hydrogen production optimization,aiming to achieve low-energy consumption,high catalytic activity,and long-term stability in the generation of target products.Here,this review critically examines the microenvironmental effects of PDE on energy and mass transfer,the electrode degradation mechanisms in the lifespan extension of electrolysis systems,and the key factors in enhancing WE for hydrogen production,providing a comprehensive summary of current research progress.The review focuses on the complex regulatory mechanisms of frequency,duty cycle,amplitude,and other factors in hydrogen evolution reaction(HER)performance within PDE strategies,revealing the interrelationships among them.Finally,the potential future directions and challenges for transitioning from laboratory studies to industrial applications are proposed.
基金supported by the National Natural Science Foundation of China(22579043,52461040,22202053,52274297)the Hainan Provincial Department of Science and Technology(G20250218018E)+2 种基金the first batch of“Nanhai New Star”industrial innovation talent platform project(202309006)the Hainan Province Science and Technology Special Fund(ZDYF2025GXJS004)the Start-up Research Foundation of Hainan University(KYQD(ZR)-21124)。
文摘Membra ne electrode assemblies(MEAs)are pivotal to advancing proton exchange membra ne water electrolysis(PEMWE),yet conventional designs suffer from limited triple-phase boundaries(TPBs),inefficient mass/charge transport,and insufficient durability.This study introduces a three-dimensional ordered pattern-array(3D OPA)architecture fabricated via a scalable laser-machined mask and hot-pressing strategy.The 3D OPA MEA achieves a current density of 3.73 A cm^(-2) at 2 V,demonstrating a 50%performance improvement over the conventional MEA(2.48 A cm^(-2)),alongside a degradation rate of 26.6μV h^(-1) in a highly dynamic accelerated stress test(AST).Additionally,numerical simulations corroborate that the OPA architecture optimizes localized oxygen diffusion and liquid water replenishment,enhancing reaction kinetics.The 3D OPA architecture enhances TPBs and establishes optimized gas-liquid tra nsport pathways,significantly improving catalyst utilization while minimizing mass transfer overpotential and bubble-induced losses.Furthermore,its interlocking design reinforces mechanical interactions,reducing ohmic resistance a nd ensuring sustained mecha nical integrity and electrochemical durability.This work provides a simple,cost-effective,and scalable approach for patterned MEAs,addressing critical barriers to PEMWE commercialization through rational TPB engineering and transport pathway optimization.
基金supported by the Natural Science Foundation of Shanghai Municipality(25ZR1401027)the National Natural Science Foundation of China(22572041,11975081,22309037,52274297,and 22402083)+1 种基金Hainan Provincial Natural Science Foundation of China(225YXQN587)Start-up Research Foundation of Hainan University(KYQD(ZR)23035)。
文摘Developing practical anion exchange membrane water electrolysis(AEMWE)technology encounters great challenges in not only cell efficiency but also long-term durability due to mechanical electrocatalyst detachment and electrochemical dissolution of active species,especially for the anodic oxygen evolution reaction(OER).Herein,a"two-pronged"approach is proposed to construct organophosphorus-protected NiFe layered double hydroxide catalysts on plasma-modified substrate,serving as an efficient and robust anode for practical AEMWE.Mechanical tests combined with operando spectroscopies and theoretical calculations demonstrate that the plasma modification strengthens the catalyst-substrate adhesion,while the organophosphorus protection prevents Fe leaching and promotes reaction kinetics during OER.The resultant electrode delivers an ultralow overpotential of 276 mV at 1 A cm^(-2),together with a remarkable stability at 0.5 A cm^(-2)over 500 h.Furthermore,assembling the optimized anode into an AEMWE device contributes to a minimized cell voltage of 1.70 V at 1 A cm^(-2),which sustains durable green hydrogen production with an economical energy consumption of 4.16 kW h Nm^(-3)H_(2).
基金supported by the National Natural Science Foundation of China(22205209)China Postdoctoral Science Foundation(2024T170837 and2022M722867)+2 种基金Joint Fund for Provincial Scientific Research and Development Plan of Henan Province(242301420039)the Key Research Projects of Higher Education Institutions of Henan Province(24A530009)Special Fund for Young Teachers from the Zhengzhou University(JC23257011)。
文摘Valence state engineering has emerged as a powerful strategy to optimize catalytic performance by modulating the electronic structure of metal active sites.However,the valence state regulation in high-entropy compounds(HECs)remains elusive due to their complex multi-element components and electronic interactions.Here,the valence states of different metals in twodimensional(2D)high entropy oxide(HEO)(FeNiMoRuV)O_(2-x)are precisely modulated through controlled pyrolysis of corresponding 2D high entropy hydroxide(HEHO)(FeNiMoRuV)(OH)_(2)under varying temperatures.Temperature-controlled pyrolysis selectively reduces the oxidation state of Ru,while simultaneously increasing the valence state of other constituent metals(Fe,Ni,Mo,and V),suggesting a competitive redox equilibrium.Notably,these low-valence Ru sites with oxygen vacancy in 2D HEO significantly reduce Ru-O bond energy and promote the generation of O-^(O)intermediates,thereby enabling oxygen evolution with a lattice oxygen mediated-oxygen vacancy site mechanism.2D HEO with low-valence Ru exhibits superior electrolytic water performance(HER/OER)compared to HEHO and other HEO with high-valence Ru,achieving a current density of 1000 mA cm^(-2)at 1.923 V,which exceeds the commercial Pt/C‖RuO_(2)system.Therefore,this study reveals the valence state regulatory mechanism of HECs and provides a solid hammer for the catalytic mechanism of valence state engineering.
基金funding provided by the National Key R&D Program of China (Grant No. 2021YFB3801301)National Natural Science Foundation of China (Grant Nos. 22075076, 22208097 and 22378119)Shanghai Pilot Program for Basic Research (22TQ1400100-4)。
文摘Seawater electrolysis for hydrogen production faces inherent challenges, including side reactions, corrosion, and scaling, stemming from the intricate composition of seawater. In response, researchers have turned to continuous water splitting using forward osmosis(FO)-driven seawater desalination. However, the necessity of a neutral electrolyte hampers this strategy due to the limited current density and scarcity of precious metals. Herein, this study applies alkali-durable FO membranes to enable self-sustaining seawater splitting, which can selectively withdraw water molecules, from seawater, via concentration gradient. The membranes demonstrates outstanding perm-selectivity of water/ions(~5830 mol mol^(-1)) during month-long alkaline resistance tests, preventing electrolyte leaching(>97% OHàretention) while maintaining ~95%water balance(V_(FO)= V_(electrolysis)) via preserved concentration gradient for consistent forward-osmosis influx of water molecules. With the consistent electrolyte environment protected by the polyamide FO membranes, the Ni Fe-Ar-P catalyst exhibits promising performance: a sustain current density of 360 m A cmà2maintained at the cell voltage of 2.10 V and 2.15 V for 360 h in the offshore seawater, preventing Cl/Br corrosion(98% rejection) and Mg/Ca passivation(99.6% rejection). This research marks a significant advancement towards efficient and durable seawater-based hydrogen production.
基金support from the National Natural Science Foundation of China(Grant No.52006029)the Promotion Foundation for Young Science and Technology Talents in Jilin Province(Grant No.QT202113)+2 种基金the Special Foundation of Industrial Innovation in Jilin Province(Grant No.2019C056-2)the Special Foundation for Outstanding Young Talents Training in Jilin(Grant No.20200104107)the UK EPSRC(EP/W03784X/1)。
文摘Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various electrolysis technologies,the emerging anion exchange membrane water electrolyser(AEMWE)exhibits the most potential for green hydrogen production,offering a potentially costeffective and sustainable approach that combines the advantages of high current density and fast start from proton exchange membrane water electrolyser(PEMWE)and low-cost catalyst from traditional alkaline water electrolyser(AWE)systems.Due to its relatively recent emergence over the past decade,a series of efforts are dedicated to improving the electrochemical reaction performance to accelerate the development and commercialization of AEMWE technology.A catalytic electrode comprising a gas diffusion layer(GDL)and a catalyst layer(CL)is usually called a gas diffusion electrode(GDE)that serves as a fundamental component within AEMWE,and also plays a core role in enhancing mass transfer during the electrolysis process.Inside the GDEs,bubbles nucleate and grow within the CL and then are transported through the GDL before eventually detaching to enter the electrolyte in the flow field.The transfer processes of water,gas bubbles,charges,and ions are intricately influenced by bubbles.This phenomenon is referred to as bubble-associated mass transfer.Like water management in fuel cells,effective bubble management is crucial in electrolysers,as its failure can result in various overpotential losses,such as activation losses,ohmic losses,and mass transfer losses,ultimately degrading the AEMWE performance.Despite significant advancements in the development of new materials and techniques in AEMWE,there is an urgent need for a comprehensive discussion focused on GDEs,with a particular emphasis on bubbleassociated mass transfer phenomena.This review aims to highlight recent findings regarding mass transfer in GDEs,particularly the impacts of bubble accumulation;and presents the latest advancements in designing CLs and GDLs to mitigate bubble-related issues.It is worth noting that a series of innovative bubble-free-GDE designs for water electrolysis are also emphasized in this review.This review is expected to be a valuable reference for gaining a deeper understanding of bubble-related mass transfer,especially the complex bubble behavior associated with GDEs,and for developing innovative practical strategies to advance AEMWE for green hydrogen production.
文摘Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct conditions required for oxygen and hydrogen evolution reaction(OER and HER).Herein,we propose a theory-directed design of Ir-based bifunctional catalysts,Ir nanoparticles supported on mesoporous carbon spheres embedded with MoSe_(2)(Ir/MoSe_(2)@MCS),leveraging a work function(WF)-induced spontaneous built-in electric field to enhance catalytic performance.They demonstrate exceptional kinetics for both OER and HER,and potential application in the practical PEM electrolyzer,showcasing the effectiveness of this innovative approach.Low overpotentials of 252 mV for OER and 28 mV for HER to drive 10 mA cm^(-2)were observed,and the PEM electrolyzer showed the current density of 2 A cm^(-2)at 1.87 V and maintained stable activity at 1.65 V for over 30 h to deliver 1 A cm^(-2).Density functional theory calculations reveal that the WF difference at Ir/MoSe_(2)interface induces a spontaneous built-in electric field with asymmetric charge distributions,that modulate the electronic environment and d-band center of Ir promoting bifunctional active phase formation.This significantly lowers reaction barriers for water splitting by balancing intermediate adsorption,endowing the bifunctional activity.
基金supported by the National Natural Science Foundation of China(22272148,22202172)financial support from the China Postdoctoral Science Foundation(2023M742947)support of the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Yangzhou University)(KYCX24_3720)。
文摘Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojunction catalyst confined in carbon nanofiber with spontaneous charge redistribution driven by high valent metal,which promotes the adsorption and transformation of intermediates and greatly reduces the reaction energy barrier for urea oxidation.The heterojunction catalyst promotes the formation of Ni^(3+)active species and accelerates the fracture of the C-N bond by enhancing selective adsorption of-NH_(2)and C=O groups in binding urea molecules driven by the spontaneous formation of nucleophilic and electrophilic sites.The catalyst achieves a low kinetic current density of 10 mA cm^(-2)at 1.35 V with a cell voltage for urea electrolysis of just 1.47 V and good durability over 60 h.Density-functional theory and in-situ spectral observation reveal that the high valent Mo promoted the 3d orbit of Ni approaching the Fermi level by adjusting the electronic structure,which enhanced spontaneous urea dehydrogenation and reduced the energy barrier for^(*)COO desorption.This study highlights the effectiveness of modulating the interfacial electronic structure to improve energy conversion efficiency.
基金financial supports provided by the National Key R&D Program of China(No.2022YFB4002002)China Grinm Group Youth FundGrinm Industrial Research Institute Innovation Fund
文摘Hydrogen energy, as one of the cleanest energy sources, has emerged as a leading candidate for replacing nonrenewable energy. However, hydrogen is not directly available from nature. Challenges such as high production costs and the need for efficient large-scale production technologies remain significant obstacles. Among the various hydrogen production methods, water electrolysis stands out due to its environmentally friendly nature and the high purity of hydrogen produced. Proton exchange membrane(PEM) electrolyzers are promising devices for hydrogen production. They exhibit the superiorities in high operational current densities exceeding 2 A cm^(-2), greater resistance to fluctuations, and improved electrolysis efficiency. A critical component of PEM water electrolyzers is the porous transport layer(PTL), which serves as an electron conductor between the membrane electrode assembly and the bipolar plate, ensuring efficient mass transport between gas and liquid phases. This review provides a comprehensive examination of PTL materials,structural configurations, surface treatments, and the resulting performance of electrolytic cells. These insights aim to guide researchers in selecting appropriate PTL materials and treatments tailored to specific practical applications. Additionally, this paper analyzes operational conditions—such as compaction pressure, temperature,water flow rate, and oxygen saturation within the electrolyzer—that influence PTL performance. These factors are crucial for researchers to holistically design and optimize PEM electrolyzer systems.
基金financially supported by the National Natural Science Foundation of China(No.22205205)the Natural Science Foundation of Zhejiang Province(No.LQ24E040002)the Science Foundation of Zhejiang Sci-Tech University(ZSTU)(Nos.21062337Y,LW-YP2024076)。
文摘Integrating electrochemical upgrading of glycerol and water electrolysis is regarded as a promising and energy-saving approach for the co-production of chemicals and hydrogen.However,developing efficient electrocatalyst towards this technology remains challenging.Herein,a metallic cobalt mediated molybdenum nitride heterostructural material has been exploited on nickel foam(Co@Mo_(2)N/NF)for the glycerol oxidation reaction(GOR)and hydrogen evolution reaction(HER).Remarkably,the obtained Co@Mo_(2)N/NF realizes eminent performance with low overpotential of 49 mV at 50 mA/cm^(2)for HER and high Faradaic efficiency of formate of 95.03%at 1.35 V vs.RHE for GOR,respectively.The systematic in-situ experiments reveal that the Co@Mo_(2)N heterostructure promotes the cleavage of C-C bond in glycerol by active CoOOH species and boosts the conversion of glycerol to aldehyde intermediates to formate product.Moreover,the density functional theory(DFT)calculations confirm the strong interaction at Co@Mo_(2)N interface,which contributes to the optimized water dissociation and the transformation of H^(*)to H^(2).Benefiting from those advantages,the built HER||GOR electrolyzer delivers a low voltage of 1.61 V at 50 mA/cm^(2),high Faradaic efficiency,and robust stability over 120 h for sustained and stable electrolysis.
基金supported by the National Key Research and Development Program of China(No.2021YFB4001305).
文摘Urgent requirements of the renewable energy boost the development of stable and clean hydrogen,which could effectively displace fossil fuels in mitigating climate changes.The efficient interconversion of hydrogen and electronic is highly based on polymer electrolyte membrane fuel cells(PEMFCs)and water electrolysis(PEMWEs).However,the high cost continues to impede large-scale commercialization of both PEMFC and PEMWE technologies,with the expense primarily attributed to noble catalysts serving as a major bottleneck.The reduction of Pt loading in PEMFCs is essential but limited by the oxygen transport resistance in the cathode catalyst layers(CCLs),while the oxygen transport in anode catalyst layers(ACLs)in PEMWEs also being focused as the Ir/IrO_(x) catalyst reduced.The pore structure and the catalyst-ionomer agglomerates play important roles in the oxygen transport process of both PEMFCs and PEMWEs due to the similarity of membrane electrode assembly(MEA).Herein,the oxygen transport mechanism of PEMFCs in pore structure and ionomer thin films in CCLs is systematically reviewed,while state-of-the-art strategies are presented for enhancing oxygen transport and performance through materials and structural design.The deeply research opens avenues for exploring similar key scientific problems in oxygen transport process of PEMWEs and their further development.
基金supported by the European Union and the Clean Hydrogen Joint Undertaking(Grant no.101112055).
文摘The global drive for sustainable energy solutions intensified interest in anion exchange membrane water electrolysis(AEMWE),as a promising hydrogen production pathway,leveraging renewable energy sources.However,widespread adoption is hindered by the high cost and non-optimised design of crucial components,such as porous transport layers(PTL)and flow fields.This study comprehensively investigates the interplay between structure,mechanics,and electrochemical performance of a low-cost knitted wire mesh PTL,focusing on its potential to enhance cell assembly and operation.Electrochemical characterisation was performed on a single 4 cm^(2)cell,using 1M KOH at 60℃.Knitted wire mesh PTL,characterised by approximately 70%porosity,2mm thickness,and 1.098 tortuosity,delivered a 33%improvement in current density compared to the standard cell configuration.Introducing a knitted PTL interlayer reduced cell voltage by 74 mV at 2 A cm^(−2)by improving compression force distribution across the active area,enhancing gas transport and maintaining optimal electrical and thermal conductivity.These findings highlight the significant potential of innovative PTL designs in AEMWE to improve mechanical and operational efficiency without increasing the cost.
基金supported by the collaborative research project of Hyundai Motor Company.Also,this work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2024-00406086,RS-2024-00338569,and RS-2024-00467191)。
文摘The commercialization of proton exchange membrane water electrolysis(PEMWE)for green hydrogen production hinges on the development of low-cost,high-performance titanium porous transport layers(PTLs).This study introduces a triple-layer Ti-PTL with a graded porous structure and a 75%ultra-high porosity backing layer,fabricated through tape casting and roll calendering.This triple-layer PTL,composed of a microporous layer,an interlayer,and a highly porous backing layer,enhances catalyst utilization,mechanical integrity,and mass transport.Digital twin technology using X-ray revealed increased contact area and triple-phase boundary at the interface with the catalyst layer,significantly improving oxygen evolution reaction kinetics.Numerical simulations demonstrated that the strategically designed porous structure of the triple-layer PTL facilitates efficient oxygen transport,mitigates oxygen accumulation,and improves reactant accessibility.Electrochemical evaluations showed improved performance,achieving 127 mV reduction in voltage at 2 A cm^(-2)compared to a commercial PTL,highlighting its potential to enhance PEMWE efficiency and cost-effectiveness.
基金financially supported by the National Natural Science Foundation of China(No.52273205)the Fundamental Research Funds for the Central Universities(No.JZ2024HGTG0297)。
文摘Anion exchange membrane water electrolysis(AEMWE)synergize the kinetic merits of alkaline systems,zero-gap configurations and compatibility with non-noble metal catalysts,offering a promising pathway toward green hydrogen production.Nevertheless,practical exploitation was hindered by critical challenges:inferior alkaline stability,insufficient mechanical integrity,and detrimental hydrogen crossover of anion exchange membranes(AEMs),which compromise both device durability and operational safety.Here,we engineered a porous expanded polytetrafluoroethylene(e-PTFE)-reinforced poly(arylene quinuclidinium)membrane that enhances AEM mechanical robustness,prevents stress-induced rupture,and suppresses hydrogen crossover during electrolyzer operation.Specifically,the reinforced poly(arylene quinuclidinium)membrane(R-PTPQui)exhibited a tensile strength of 56 MPa and an elongation at break of 55%.Moreover,it effectively reduced hydrogen permeation in the electrolyzer,achieving an extremely low H_(2)-to-O_(2)(HTO)value of 0.44 vol%at 0.1 A·cm^(-2).The R-PTPQui-based electrolyzer achieved a high current density of 4.9 A·cm^(-2)at 2.0 V and a Faradaic efficiency of 98.6%using a non-precious anode catalyst.These advances significantly strength the compatibility of poly(arylene quinuclidinium)-based AEMs for industrial-scale green hydrogen generation.
基金supported by the National Natural Science Foundation of China(Grant No.22275210)the Natural Science Foundation of Shandong Province(Grant No.ZR2024QB025,ZR2023ME155)the Taishan Scholar Project of Shandong Province(tsqn202306226)。
文摘Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a significant challenge.Herein,we report a vacancy occupation-triggered phase transition strategy to fabricate a core-shell 1T phase nanorod structure,which is composed of S-vacancies decorated MoS_(2)as the core,and N,P co-doped carbons as the shell(1T-MoS_(2)@NPC).The co-insertion of N and P dopants into MoS_(2)can occupy partial S-vacancies,triggering a phase transformation from the semiconducting 2H phase to the conducting 1T phase with a reduced energy barrier.Profiting from the strong coupling effect between N,P dopants and S-vacancies,the as-made 1T-MoS_(2)@NPC exhibits excellent electrocatalytic activity for both HER(η_(10)=148 m V)and OER(η_(10)=232 mV)in alkaline solution.Meanwhile,a low cell voltage of 1.62 V is needed to drive a current density of 10mA cm^(-2)in 1.0 M KOH electrolyte.The theoretical calculation results reveal that the S-vacancies decorated C atoms in the meta-position relative to N,P atoms represent the most active HER and OER sites,which synergistically upshift the d band center and balance the rate-determining step,thus ensuring the simultaneous optimization of adsorption free energy and electronic structure.This vacancy-occupation-derived phase transformation strategy caused by non-metallic doping may provide valuable guidance for enhancing the performance of alkaline water electrolysis.
文摘Since the beginning of the 20th century,alkaline electrolysis has been used as a proven method for producing hydrogen on a megawatt scale.The existence of parasitic shunt currents in alkaline water electrolysis,which is utilized to produce clean hydrogen,is investigated in this work.Analysis has been done on a 20-cell stack.Steel end plates,bipolar plates,and an electrolyte concentration of 6 M potassium hydroxide are all included in the model.The Butler-Volmer kinetics equations are used to simulate the electrode surfaces.Ohmic losses are taken into consideration in both the electrode and electrolyte phases,although mass transport constraints in the gas phase are not.Using an auxiliary sweep to solve equations,the model maintains an isothermal condition at 85℃ while adjusting the average cell voltage between 1.3 and 1.8 V.The results show that lower shunt currents in the outlet channels as opposed to the intake channels are the result of the electrolyte’s lower effective conductivity in the upper channels,which is brought on by a lower volume fraction of the electrolyte.Additionally,it has been seen that the shunt currents intensify as the stack gets closer to the conclusion.Efficiency is calculated by dividing the maximum energy output(per unit of time)that a fuel cell operating under comparable conditions might produce by the electrical energy needed to generate that output inside the stack.At first,energy efficiency increases due to the rise in coulombic efficiency,peaking around 1400 mA.The subsequent decline after reaching 1400 mA is linked to an increase in stack voltage at elevated current levels.
基金supported by the National Key Research and Development Program of China(No.2021YFA1500400)the National Natural Science Foundation of China(No.22175163)+3 种基金the Natural Science Foundation of Anhui Province(No.2208085UD04)Anhui Development and Reform Commission(Nos.AHZDCYCX-LSDT2023-08 and AHZDCYCX-LSDT2023-07)the Department of Ecology and Environment of Anhui Province(No.2023hb0018)the Fundamental Research Funds for the Central Universities(No.WK2060000016).
文摘Despite the cost and activity advantages,ruthenium-based oxygen evolution reaction(OER)catalysts face severe stability problems for proton exchange membrane water electrolysis(PEM-WE)due to Ru dissolution.Although tremendous attention has been paid to enhancing the stability and activity under small current density in three electrode systems,there still lacks validation under industrial current density at the device level.Aiming at this issue,we report highly active and durable ruthenium-iridium alloyed oxides(IrRuO_(x))as the acidic OER catalyst for PEM-WE with exceptional durability for 1600 h at an industrial current density of 2.0 A·cm^(−2).X-ray absorption spectroscopy reveals that the introduction of iridium modulates the electronic structure of Ru and strengthens the local Ru–O bonds in RuO_(2),which is crucial for ensuring activity and stability.As a result,in comparison with its RuO_(2) counterpart,IrRuO_(x) works stably against the Ru leaching-induced catalytic layer breakage during the stability test.This work demonstrates the great potential of IrRuO_(x) as the practical OER catalyst for the application in PEM-WE.
基金the Natural Science Foundation of Tianjin(No.22JCZDJC00100)the Sinopec Technology Development Project(No.224211)the National Natural Science Foundation of China(No.21878231)。
文摘In alkaline water electrolysis(AWE),the development of high-performance membranes with excellent ionic conductivity,robust mechanical stability,and superior gas barrier properties is crucial for efficient hydrogen energy conversion.This study proposes a superhydrophilic composite membrane based on a synergistic hydrogen bonding and coordination strategy for structural regulation and performance enhancement in AWE.During the non-solvent-induced phase separation(NIPS)process,polyvinylpyrrolidone(PVP)and tannic acid(TA)form a stable hydrogen-bonded network in the water coagulation bath,effectively inducing the construction of a hierarchical porous structure with coexisting finger-like and sponge-like pores.This design enables efficient OH^(-)transport while significantly improving gas barrier properties.On this basis,coordination between TA and ZrO_(2) particles further establishes an organicinorganic micro-interlocking structure,enhancing structural stability and interfacial continuity of the membrane.The optimized PTP3 composite membrane exhibits outstanding comprehensive properties,including high tensile strength(38.77 MPa),elevated bubble point pressure(4.27 bar),and low area resistance(0.12Ωcm^(2)),achieving a current density of 779 mA cm^(-2)at 2 V.In addition,the membrane maintains excellent structural integrity and performance stability after continuous operation for 300 h in a high-temperature,strongly alkaline environment,with negligible degradation.This study offers a novel interfacial hydrogen bonding-coordination design strategy for the development of high-performance,energy-efficient AWE membranes,providing a solid foundation for improving hydrogen production efficiency and enabling large-scale alkaline electrolysis applications.
基金financially supported by the National Natural Science Foundation of China(Nos.22209115,52472226,and U23A20573)the Key Research and Development Program of Shandong Province(No.2022CXGC010305)+2 种基金Guangdong Basic and Applied Basic Research Foundation(Nos.2023B1515120022,2022B1515120001 and 2025A1515011809)Shenzhen Science and Technology Innovation Program(Nos.RCBS20231211090522040,KJZD20240903095610014 and KJZD20240903095712017)the High-Level Professional Team in Shenzhen(No.KQTD20210811090045006)
文摘Proton exchange membrane water electrolysis(PEMWE)has emerged as a promising technology for hydrogen production,offering high efficiency,superior hydrogen purity,and a compact system design.However,its widespread adoption is hindered by the harsh acidic environment and the intrinsically slow kinetics of the oxygen evolution reaction(OER)at the anode.Addressing these challenges requires the development of robust,acidresistant anode catalysts.Among various candidates,iridium-based catalysts(IBCs)have attracted significant attention owing to their exceptional catalytic activity and stability under acidic conditions.Nevertheless,the high cost and limited availability of Ir impede their large-scale application.To mitigate these issues,extensive research has been devoted to strategies that reduce Ir loading while enhancing catalytic performance.This review provides a comprehensive and systematic overview of recent advances in the rational design of IBCs,focusing on strategies such as multi-scale morphology control,heteroatom doping,alloying,defect engineering,heterostructure construction,and support interactions.
