Large-scale green hydrogen production technology,based on the electrolysis of water powered by renewable energy,relies heavily on non-precious metal oxygen evolution reactions(OER)electrocatalysts with high activity a...Large-scale green hydrogen production technology,based on the electrolysis of water powered by renewable energy,relies heavily on non-precious metal oxygen evolution reactions(OER)electrocatalysts with high activity and stability under industrial conditions(6 M KOH,60℃-80℃)at large current density.Here,we construct Fe and Co co-incorporated nickel(oxy)hydroxide(Fe_(2.5)Co_(2.5)Ni_(10)O_(y)H_(z)@NFF)via a multi-metal electrodeposition,which exhibits outstanding OER performance(overpotential:185 mV@10 mA cm^(-2)).Importantly,an overwhelming stability for more than 1100 h at 500 mA cm^(-2)under industrial conditions is achieved.Our combined experimental and computational investigation reveals the surface-reconstructedγ-NiOOH with a high valence state is the active layer,where the optimal(Fe,Co)co-incorporation tunes its electronic structure,changes the potential determining step,and reduces the energy barrier,leading to ultrahigh activity and stability.Our findings demonstrate a facile way to achieve an electrocatalyst with high performance for the industrial production of green hydrogen.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
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
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
The high chloride(Cl)concentration in seawater presents a critical challenge for hydrogen production via seawater electrolysis by deactivating catalysts through active site passivation,highlighting the need for cataly...The high chloride(Cl)concentration in seawater presents a critical challenge for hydrogen production via seawater electrolysis by deactivating catalysts through active site passivation,highlighting the need for catalyst innovation.Herein,in situ boron-doped Co_(2)P/CoP(B-Co_(x)P)ultrathin nanosheet arrays are prepared as high-performance bifunctional electrocatalysts for seawater decomposition.Density functional theory(DFT)simulations,comprehensive characterizations,and in-situ analyses reveal that boron doping enhances electron density around Co centers,induces lattice distortions,and significantly elevates catalytic activity and durability.Moreover,boron doping reduces*Cl retention time at active sites—defined as the DFT-derived residence time of adsorbed Cl intermediates based on their adsorption energies—effectively mitigating Cl-induced poisoning.In a three-electrode system,B-Co_(x)P achieves exceptional bifunctional performance with overpotentials of 11 mV for hydrogen evolution reaction and 196 mV for oxygen evolution reaction to deliver 10 and 50 mA·cm^(-2),respectively—a result that showcases its superior bifunctional properties surpassing noble metal-based counterparts.In an alkaline electrolyzer,it delivers 1.56 A·cm^(-2)at 2.87 V for seawater electrolysis with outstanding stability over 500 h,preserving active site integrity via boron's robust protective role.This study defines a paradigm for designing advanced seawater electrolysis catalysts through a strategic in-situ doping approach.展开更多
Green hydrogen(H_(2))produced by renewable energy powered alkaline water electrolysis is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.However,efficient and economic...Green hydrogen(H_(2))produced by renewable energy powered alkaline water electrolysis is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.However,efficient and economic H_(2) production by alkaline water electrolysis is hindered by the sluggish hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Therefore,it is imperative to design and fabricate high-active and low-cost non-precious metal catalysts to improve the HER and OER performance,which affects the energy efficiency of alkaline water electrolysis.Ni_(3)S_(2) with the heazlewoodite structure is a potential electrocatalyst with near-metal conductivity due to the Ni–Ni metal network.Here,the review comprehensively presents the recent progress of Ni_(3)S_(2)-based electrocatalysts for alkaline water electrocatalysis.Herein,the HER and OER mechanisms,performance evaluation criteria,preparation methods,and strategies for performance improvement of Ni_(3)S_(2)-based electrocatalysts are discussed.The challenges and perspectives are also analyzed.展开更多
The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conduci...The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conducive to the enhancement of electrocatalytic activity.Herein,theoretical simulations first disclose the charge transfer trend and reinforced inherent electron conduction around the epitaxial heterointerface between Ru clusters and Ni_(3)N substrate(cRu-Ni_(3)N),thus leading to the optimized adsorption behaviors and reduced activation energy barriers.Subsequently,the defectrich nanosheets with the epitaxially grown cRu-Ni_(3)N heterointerface are successfully constructed.Impressively,by virtue of the superiority of intrinsic activity and reaction kinetics,such unique epitaxial heterostructure exhibits remarkable bifunctional catalytic activity toward electrocatalytic OER(226 mV@20 mA cm^(−2))and HER(32 mV@10 mA cm^(−2))in alkaline media.Furthermore,it also shows great application prospect in alkaline freshwater and seawater splitting,as well as solar-to-hydrogen integrated system.This work could provide beneficial enlightenment for the establishment of advanced electrocatalysts with epitaxial heterointerfaces.展开更多
Anion exchange membrane(AEM)water electrolyzers are promising energy devices for the production of clean hydrogen from seawater.However,the lack of active and robust electrocatalysts for the oxygen evolution reaction(...Anion exchange membrane(AEM)water electrolyzers are promising energy devices for the production of clean hydrogen from seawater.However,the lack of active and robust electrocatalysts for the oxygen evolution reaction(OER)severely impedes the development of this technology.In this study,a ternary layered double hydroxide(LDH)OER electrocatalyst(NiFeCo-LDH)is developed for high-performance AEM alkaline seawater electrolyzers.The AEM alkaline seawater electrolyzer catalyzed by the NiFeCo LDH shows high seawater electrolysis performance(0.84 A/cm^(2)at 1.7 Vcell)and high hydrogen production efficiency(77.6%at 0.5 A/cm^(2)),thus outperforming an electrolyzer catalyzed by a benchmark IrO_(2)electrocatalyst.The NiFeCo-LDH electrocatalyst greatly improves the kinetics of the AEM alkaline seawater electrolyzer,consequently reducing its activation loss and leading to high performance.Based on the results,this NiFeCo-LDH-catalyzed AEM alkaline seawater electrolyzer can likely surpass the energy conversion targets of the US Department of Energy.展开更多
An advantageous porous architecture of electrodes is pivotal in significantly enhancing alkaline water electrolysis(AWE)efficiency by optimizing the mass transport mechanisms.This effect becomes even more pronounced w...An advantageous porous architecture of electrodes is pivotal in significantly enhancing alkaline water electrolysis(AWE)efficiency by optimizing the mass transport mechanisms.This effect becomes even more pronounced when aiming to achieve elevated current densities.Herein,we employed a rapid and scalable laser texturing process to craft novel multi-channel porous electrodes.Particularly,the obtained electrodes exhibit the lowest Tafel slope of 79 mV dec^(-1)(HER)and 49 mV dec^(-1)(OER).As anticipated,the alkaline electrolyzer(AEL)cell incorporating multi-channel porous electrodes(NP-LT30)exhibited a remarkable improvement in cell efficiency,with voltage drops(from 2.28 to 1.97 V)exceeding 300 mV under 1 A cm^(-1),compared to conventional perforated Ni plate electrodes.This enhancement mainly stemmed from the employed multi-channel porous structure,facilitating mass transport and bubble dynamics through an innovative convection mode,surpassing the traditional convection mode.Furthermore,the NP-LT30-based AEL cell demonstrated exceptional durability for 300 h under 1.0 A cm^(-2).This study underscores the capability of the novel multi-channel porous electrodes to expedite mass transport in practical AWE applications.展开更多
Available online Alkaline water electrolysis(AWE)is a prominent technique for obtaining a sustainable hydrogen source and effectively managing the energy infrastructure.Noble metal-based electrocatalysts,owing to thei...Available online Alkaline water electrolysis(AWE)is a prominent technique for obtaining a sustainable hydrogen source and effectively managing the energy infrastructure.Noble metal-based electrocatalysts,owing to their exceptional hydrogen binding energy,exhibit remarkable catalytic activity and long-term stability in the hydrogen evolution reaction(HER).However,the restricted accessibility and exorbitant cost of noble-metal materials pose obstacles to their extensive adoption in industrial contexts.This review investigates strategies aimed at reducing the dependence on noble-metal electrocatalysts and developing a cost-effective alkaline HER catalyst,while considering the principles of sustainable development.The initial discussion covers the fundamental principle of HER,followed by an overview of prevalent techniques for synthesizing catalysts based on noble metals,along with a thorough examination of recent advancements.The subsequent discussion focuses on the strategies employed to improve noble metalbased catalysts,including enhancing the intrinsic activity at active sites and increasing the quantity of active sites.Ultimately,this investigation concludes by examining the present state and future direction of research in the field of electrocatalysis for the HER.展开更多
Establishing an energy-saving and affordable hydrogen production route from infinite seawater presents a promising strategy for achieving carbon neutrality and low-carbon development.Compared with the kinetically slug...Establishing an energy-saving and affordable hydrogen production route from infinite seawater presents a promising strategy for achieving carbon neutrality and low-carbon development.Compared with the kinetically sluggish oxygen evolution reaction(OER),the thermodynamically advantageous sulfion oxidation reaction(SOR)enables the S^(2-)pollutants recovery while reducing the energy input of water electrolysis.Here,a nanoporous NiMo alloy ligament(np-NiMo)with AlNi_(3)/Al_(5)Mo heterostructure was prepared for hydrogen evolution reaction(HER,-0.134V versus reversible hydrogen electrode(vs.RHE)at 50mA/cm^(2)),which needs an Al_(89)Ni_(10)Mo_(1)as a precursor and dealloying operation.Further,the np-NiMo alloy was thermal-treated with S powder to generate Mo-doped NiS_(2)(np-NiMo-S)for OER(1.544V vs.RHE at 50mA/cm^(2))and SOR(0.364 V vs.RHE at 50mA/cm^(2)),while still maintaining the nanostructuring advantages.Moreover,for a two-electrode electrolyzer system with np-NiMo cathode(1M KOH+seawater)coupling np-NiMo-S anode(1mol/L KOH+seawater+1 mol/L Na_(2)S),a remarkably ultra-low cell potential of 0.532 V is acquired at 50mA/cm^(2),which is about 1.015 V below that of normal alkaline seawater splitting.The theory calculations confirmed that the AlNi_(3)/Al_(5)Mo heterostructure within np-NiMo promotes H_(2)O dissociation for excellent HER,while the Mo-dopant of np-NiMo-S lowers energy barriers for the rate-determining step from^(*)S_(4)to^(*)S_(8).This work develops two kinds of NiMo alloy with tremendous prominence for achieving energy-efficient hydrogen production from alkaline seawater and sulfur recycling from sulfion-rich sewage.展开更多
The hydrogen evolution reaction(HER)in alkaline water electrolysis faces significant kinetic and thermodynamic challenges that hinder its efficiency and scalability for sustainable hydrogen production.Herein,we employ...The hydrogen evolution reaction(HER)in alkaline water electrolysis faces significant kinetic and thermodynamic challenges that hinder its efficiency and scalability for sustainable hydrogen production.Herein,we employed an in-situ synthesis strategy to incorporate H atoms into the PdRu alloy lattice to form H_(Inc)-PdRu electrocatalyst,thereby modulating its electronic structure and enhancing its alkaline HER performance.We demonstrate that the incorporation of H atoms significantly improves electrocatalytic activity,achieving a remarkably low overpotential of 25 mV at 10 mA cm^(-2)compared with the Pd,Ru and PdRu catalysts while maintaining robust catalyst stability.Operando spectroscopic analysis indicates that H insertion into the H_(Inc)-PdRu electrocatalyst enhances the availability of H_(2)O^(*)at the surface,promoting water dissociation at the active sites.Theoretical calculations proposed that the co-incorporating H and Ru atoms induces s-d orbital coupling within the Pd lattices,effectively weakening hydrogen adsorption strength and optimizing the alkaline HER energetics.This work presents a facile approach for the rational design of bimetallic electrocatalysts for efficient and stable alkaline water electrolysis for renewable hydrogen production.展开更多
Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchang...Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchange membrane water electrolysis.Here,homogeneous high entropy oxide(HEO)film is in-situ fabricated on nickel foam(NF)substrate via magnetron sputtering technology without annealing process in air,which is composed of many spinel-structured(FeCoNiCrMo)_(3)O_(4) grains with an average particle size of 2.5 nm.The resulting HEO film(abbreviated as(FeCoNiCr-Mo)_(3)O_(4))exhibits a superior OER performance with a low OER overpotential of 216 mV at 10 mA cm^(–2) and steadily operates at 100 mA cm^(–2) for 200 h with a decay of only 272μV h^(–1),which is far better than that of commercial IrO_(2) catalyst(290 mV,1090μV h^(–1)).Tetramethylammonium cation(TMA^(+))probe experiment,activation energy analysis and theoretical calculations unveil that the OER on(FeCoNiCrMo)_(3)O_(4) follows an adsorbate evolution mechanism pathway,where the energy barrier of rate-determining step for OER on(FeCoNiCrMo)_(3)O_(4) is substantially lowered.Also,methanol molecular probe experiment suggests that a weakened ^(*)OH bonding on the(FeCoNiCrMo)_(3)O_(4) surface and a rapid deprotonation of ^(*)OH,further enhancing its OER performance.This work provides a feasible solution for designing efficient high entropy oxides electrocatalysts for OER,accelerating the practical process of water electrolysis for H2 production.展开更多
The reasonable development and design of high-efficiency and low-cost electrocatalysts for hydrogen evolution reaction(HER)under industrial current densities are imperative for achieving carbon neutrality,while also p...The reasonable development and design of high-efficiency and low-cost electrocatalysts for hydrogen evolution reaction(HER)under industrial current densities are imperative for achieving carbon neutrality,while also posing challenges.In this study,an efficient electrocatalyst is successfully constructed through electrodeposition methods,which consists of monodispersed Pt loaded on amorphous/crystalline nickel–iron layered double hydroxide(Pt-SAs/ac-NiFe LDH).The Pt-SAs/ac-NiFe LDH demonstrates an elevated mass activity of 17.66 A mg_(Pt)^(−1)and a significant turnover frequency of 17.90 s^(−1)for HER in alkaline conditions under the overpotential of 100 mV.Meanwhile,for alkaline freshwater and seawater,Pt-SAs/ac-NiFe LDH exhibits ultra-low overpotentials of 141 and 138 mV to reach 1000 mA cm^(−2),respectively.Remarkably,it maintains stable operation for 100 h at 500 mA cm^(−2),showcasing its robustness and reliability.In situ Raman spectra reveal that Pt single atoms(Pt-SAs)accelerate interfacial water dissociation,thereby enhancing the HER kinetics in Pt-SAs/ac-NiFe LDH.Furthermore,theoretical calculation results show significant electronic interaction between the Pt-SAs and the ac-NiFe LDH support.The interaction significantly enhances water adsorption and dissociation,and balances the adsorption/desorption of hydrogen intermediates,ultimately improving HER performance.This research provides a viable method for designing efficient HER catalysts for water electrolysis in alkaline freshwater and seawater under industrial current densities.展开更多
Developing effective and practical electrocatalyst under industrial electrolysis conditions is critical for renewable hydrogen production.Herein,we report the self-supporting NiFe LDH-MoS_(x)integrated electrode for w...Developing effective and practical electrocatalyst under industrial electrolysis conditions is critical for renewable hydrogen production.Herein,we report the self-supporting NiFe LDH-MoS_(x)integrated electrode for water oxidation under normal alkaline test condition(1 M KOH at 25℃)and simulated industrial electrolysis conditions(5 M KOH at 65℃).Such optimized electrode exhibits excellent oxygen evolution reaction(OER)performance with overpotential of 195 and 290 mV at current density of 100 and 400 mA·cm^(-2)under normal alkaline test condition.Notably,only over-potential of 156 and 201 mV were required to achieve the current density of 100 and 400mA·cm^(-2)under simulated industrial electrolysis conditions.No significant degradations were observed after long-term durability tests for both conditions.When using in two-electrode system,the operational voltages of 1.44 and 1.72 V were required to achieve a current density of 10 and 100 mA·cm^(-2)for the overall water splitting test(NiFe LDH-MoS_(x)/INF||20%Pt/C).Additionally,the operational voltage of employing NiFe LDH-MoS_(x)/INF as both cathode and anode merely require 1.52 V at 50mA·cm^(-2)at simulated industrial electrolysis conditions.Notably,a membrane electrode assembly(MEA)for anion exchange membrane water electrolysis(AEMWEs)using NiFe LDH-MoS_(x)/INF as an anode catalyst exhibited an energy conversion efficiency of 71.8%at current density of 400 mA·cm^(-2)in 1 M KOH at 60℃.Further experimental results reveal that sulfurized substrate not only improved the conductivity of NiFe LDH,but also regulated its electronic configurations and atomic composition,leading to the excellent activity.The easy-obtained and cost-effective integrated electrodes are expected to meet the large-scale application of industrial water electrolysis.展开更多
The key challenge of industrial water electrolysis is to design catalytic electrodes that can stabilize high current density with low power consumption(i.e.,overpotential),while industrial harsh conditions make the ba...The key challenge of industrial water electrolysis is to design catalytic electrodes that can stabilize high current density with low power consumption(i.e.,overpotential),while industrial harsh conditions make the balance between electrode activity and stability more difficult.Here,we develop an efficient and durable electrode for water oxidation reaction(WOR),which yields a high current density of 1000 mA cm−2 at an overpotential of only 284 mV in 1M KOH at 25°C and shows robust stability even in 6M KOH strong alkali with an elevated temperature up to 80°C.This electrode is fabricated from a cheap nickel foam(NF)substrate through a simple one-step solution etching method,resulting in the growth of ultrafine phosphorus doped nickel-iron(oxy)hydroxide[P-(Ni,Fe)O_(x)H_(y)]nanoparticles embedded into abundant micropores on the surface,featured as a self-stabilized catalyst–substrate fusion electrode.Such self-stabilizing effect fastens highly active P-(Ni,Fe)O_(x)H_(y)species on conductive NF substrates with significant contribution to catalyst fixation and charge transfer,realizing a win–win tactics for WOR activity and durability at high current densities in harsh environments.This work affords a cost-effective WOR electrode that can well work at large current densities,suggestive of the rational design of catalyst electrodes toward industrial-scale water electrolysis.展开更多
Design of the catalyst for efficient water dissociation and hydrogen recombination is paramount in enhancement of the alkaline water electrolysis kinetics.Herein,we reported a delicate hierarchical(VO)_(2) P_(2)O_(7)-...Design of the catalyst for efficient water dissociation and hydrogen recombination is paramount in enhancement of the alkaline water electrolysis kinetics.Herein,we reported a delicate hierarchical(VO)_(2) P_(2)O_(7)-Ni_(2) P@NF(VPO-Ni_(2) P@NF)hybrid catalyst that operated efficiently in alkaline media.The VPO and Ni_(2) P respectively act as the water dissociation promoter and the hydrogen recombination center,which synergistically propel water adsorption/dissociation and H intermediates recombination.The resulting synergistic interfaces between VPO and Ni_(2) P are verified to afford the catalyst an outstanding performance for hydrogen evolution reaction in alkaline media with an overpotential of 154 mV at 10 mA cm^(-2),Tafel slope of 65 mV dec^(-1),and remarkable durability.Furthermore,the catalyst presents the potential for overall water splitting.This work may shed fresh light on the high-performance electrocatalyst design and the application of VPO on water electrolysis.展开更多
Highly efficient hydrogen evolution reaction(HER)electrocatalysts play a crucial part in generating green hydrogen.Herein,an electrochemical activation approach was applied to design 6.7 Rh-Ni_(2)P-800CV electrocataly...Highly efficient hydrogen evolution reaction(HER)electrocatalysts play a crucial part in generating green hydrogen.Herein,an electrochemical activation approach was applied to design 6.7 Rh-Ni_(2)P-800CV electrocatalysts in alkaline electrolytes.The results confirm that the generation of metal oxide sites through the electrochemical activation strategy can effectively improve the intrinsic activity of 6.7 Rh-Ni_(2)P-800CV.The density functional calculations further confirm that metal oxide active sites are favorable for H2O adsorption and activation and H*adsorption/desorption.The 6.7 Rh-Ni_(2)P-800CV possesses significantly enhanced HER performance with low overpotential(25 mV at 10 mA·cm^(2)),small Tafel(60 mV·dec^(-1))and robust stability in 1.0 M KOH,outperforming Pt/C and 6.7 Rh-Ni_(2)P counterparts.Meanwhile,6.7 Rh-Ni_(2)P-800CV can even operate at a large current density(550 mA·cm^(-2))up to 90 h with an overpotential of 320 mV,which meets the requirements of industrial water splitting.What's more,the overall watersplitting systems(6.7 Rh-Ni_(2)P-800CV‖6.7 Rh-Ni_(2)P-800CV)can be directly driven by the solar cell.This work highlights that electrochemical activation technology provides a robust avenue toward constructing efficient electrocatalysts for sustainable energy conversion.展开更多
Despite considerable efforts to develop electrolyzers for energy conversion,progress has been hindered during the implementation stage by different catalyst development requirements in academic and industrial research...Despite considerable efforts to develop electrolyzers for energy conversion,progress has been hindered during the implementation stage by different catalyst development requirements in academic and industrial research.Herein,a coherent workflow for the efficient transition of electrocatalysts from basic research to application readiness for the alkaline oxygen evolution reaction is proposed.To demonstrate this research approach,La_(0.8)Sr_(0.2)CoO_(3) is selected as a catalyst,and its electrocatalytic performance is compared with that of the benchmark material NiFe_(2)O_(4).The La_(0.8)Sr_(0.2)CoO_(3) catalyst with the desired dispersity is successfully synthesized by scalable spray-flame synthesis.Subsequently,inks are formulated using different binders(Nafion^(®),Naf;Sustainion^(®),Sus),and nickel substrates are spray coated,ensuring a homogeneous catalyst distribution.Extensive electrochemical evaluations,including several scale-bridging techniques,highlight the efficiency of the La_(0.8)Sr_(0.2)CoO_(3) catalyst.Experiments using the scanning droplet cell(SDC)indicate good lateral homogeneity for La_(0.8)Sr_(0.2)CoO_(3) electrodes and NiFe_(2)O_(4)-Sus,while the NiFe_(2)O_(4)-Naf film suffers from delamination.Among the various half-cell techniques,SDC proves to be a valuable tool to quickly check whether a catalyst layer is suitable for full-cell-level testing and will be used for the fast-tracking of catalysts in the future.Complementary compression and flow cell experiments provide valuable information on the electrodes'behavior upon exposure to chemical and mechanical stress.Finally,parameters and conditions simulating industrial settings are applied using a zero-gap cell.Findings from various research fields across different scales obtained based on the developed coherent workflow contribute to a better understanding of the electrocatalytic system at the early stages of development and provide important insights for the evaluation of novel materials that are to be used in large-scale industrial applications.展开更多
With the in-depth implementation of sustainable development strategies,hydrogen energy as a clean energy source is receiving increasing attention[1,2].Among the various methods of hydrogen production,the electrocataly...With the in-depth implementation of sustainable development strategies,hydrogen energy as a clean energy source is receiving increasing attention[1,2].Among the various methods of hydrogen production,the electrocatalytic decomposition of abundant seawater into hydrogen utilizing renewable energy has emerged as a green and promising approach.However,natural seawater contains complex components,such as halide ions,which lead to the corrosion of catalysts or the occurrence of competitive side reactions during the electrolysis process[3].展开更多
基金supported by the Science and Technology Development Fund(FDCT)from Macao SAR(0050/2023/RIB2,0023/2023/AFJ,006/2022/ALC,0111/2022/A2,0105/2023/RIA2)Multi-Year Research Grants(MYRG-GRG2023-00010-IAPME,and MYRG2022-00026-IAPME)from Research&Development Office at University of MacaoShenzhen-Hong Kong-Macao Science and Technology Research Programme(Type C)(SGDX20210823103803017)from Shenzhen.
文摘Large-scale green hydrogen production technology,based on the electrolysis of water powered by renewable energy,relies heavily on non-precious metal oxygen evolution reactions(OER)electrocatalysts with high activity and stability under industrial conditions(6 M KOH,60℃-80℃)at large current density.Here,we construct Fe and Co co-incorporated nickel(oxy)hydroxide(Fe_(2.5)Co_(2.5)Ni_(10)O_(y)H_(z)@NFF)via a multi-metal electrodeposition,which exhibits outstanding OER performance(overpotential:185 mV@10 mA cm^(-2)).Importantly,an overwhelming stability for more than 1100 h at 500 mA cm^(-2)under industrial conditions is achieved.Our combined experimental and computational investigation reveals the surface-reconstructedγ-NiOOH with a high valence state is the active layer,where the optimal(Fe,Co)co-incorporation tunes its electronic structure,changes the potential determining step,and reduces the energy barrier,leading to ultrahigh activity and stability.Our findings demonstrate a facile way to achieve an electrocatalyst with high performance for the industrial production of green hydrogen.
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.
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 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.
基金supported by the National Natural Science Foundation of China(No.U24A20550,52273264)Youth Science Foundation Project ofChina(No.22409056)+1 种基金the Key Project of the Heilongjiang Provincial Natural Science Foundation(No.ZD2024B001)the Excellent Youth Project ofHeilongjiang Provincial Natural Science Foundation of China(No.LH2019B020).
文摘The high chloride(Cl)concentration in seawater presents a critical challenge for hydrogen production via seawater electrolysis by deactivating catalysts through active site passivation,highlighting the need for catalyst innovation.Herein,in situ boron-doped Co_(2)P/CoP(B-Co_(x)P)ultrathin nanosheet arrays are prepared as high-performance bifunctional electrocatalysts for seawater decomposition.Density functional theory(DFT)simulations,comprehensive characterizations,and in-situ analyses reveal that boron doping enhances electron density around Co centers,induces lattice distortions,and significantly elevates catalytic activity and durability.Moreover,boron doping reduces*Cl retention time at active sites—defined as the DFT-derived residence time of adsorbed Cl intermediates based on their adsorption energies—effectively mitigating Cl-induced poisoning.In a three-electrode system,B-Co_(x)P achieves exceptional bifunctional performance with overpotentials of 11 mV for hydrogen evolution reaction and 196 mV for oxygen evolution reaction to deliver 10 and 50 mA·cm^(-2),respectively—a result that showcases its superior bifunctional properties surpassing noble metal-based counterparts.In an alkaline electrolyzer,it delivers 1.56 A·cm^(-2)at 2.87 V for seawater electrolysis with outstanding stability over 500 h,preserving active site integrity via boron's robust protective role.This study defines a paradigm for designing advanced seawater electrolysis catalysts through a strategic in-situ doping approach.
基金supported by the National Key Research and Development Program(No.2022YFB4202200)the Fundamental Research Funds for the Central Universities.
文摘Green hydrogen(H_(2))produced by renewable energy powered alkaline water electrolysis is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.However,efficient and economic H_(2) production by alkaline water electrolysis is hindered by the sluggish hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Therefore,it is imperative to design and fabricate high-active and low-cost non-precious metal catalysts to improve the HER and OER performance,which affects the energy efficiency of alkaline water electrolysis.Ni_(3)S_(2) with the heazlewoodite structure is a potential electrocatalyst with near-metal conductivity due to the Ni–Ni metal network.Here,the review comprehensively presents the recent progress of Ni_(3)S_(2)-based electrocatalysts for alkaline water electrocatalysis.Herein,the HER and OER mechanisms,performance evaluation criteria,preparation methods,and strategies for performance improvement of Ni_(3)S_(2)-based electrocatalysts are discussed.The challenges and perspectives are also analyzed.
基金financially sponsored by the National Natural Science Foundation of China(Grant No.22075223,22179104)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(2021-ZD-4)the Fundamental Research Funds for the Central Universities(No.2020-YB-012)。
文摘The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conducive to the enhancement of electrocatalytic activity.Herein,theoretical simulations first disclose the charge transfer trend and reinforced inherent electron conduction around the epitaxial heterointerface between Ru clusters and Ni_(3)N substrate(cRu-Ni_(3)N),thus leading to the optimized adsorption behaviors and reduced activation energy barriers.Subsequently,the defectrich nanosheets with the epitaxially grown cRu-Ni_(3)N heterointerface are successfully constructed.Impressively,by virtue of the superiority of intrinsic activity and reaction kinetics,such unique epitaxial heterostructure exhibits remarkable bifunctional catalytic activity toward electrocatalytic OER(226 mV@20 mA cm^(−2))and HER(32 mV@10 mA cm^(−2))in alkaline media.Furthermore,it also shows great application prospect in alkaline freshwater and seawater splitting,as well as solar-to-hydrogen integrated system.This work could provide beneficial enlightenment for the establishment of advanced electrocatalysts with epitaxial heterointerfaces.
基金supported by the Fundamental Research Program of the Korean Institute of Materials Science(PNK7550)the National Research Council of Science&Technology(NST)grant by the MSIT(CAP21000-000)the New&Renewable Energy Core Technology Program of the KETEP(20213030040520)in the Republic of Korea。
文摘Anion exchange membrane(AEM)water electrolyzers are promising energy devices for the production of clean hydrogen from seawater.However,the lack of active and robust electrocatalysts for the oxygen evolution reaction(OER)severely impedes the development of this technology.In this study,a ternary layered double hydroxide(LDH)OER electrocatalyst(NiFeCo-LDH)is developed for high-performance AEM alkaline seawater electrolyzers.The AEM alkaline seawater electrolyzer catalyzed by the NiFeCo LDH shows high seawater electrolysis performance(0.84 A/cm^(2)at 1.7 Vcell)and high hydrogen production efficiency(77.6%at 0.5 A/cm^(2)),thus outperforming an electrolyzer catalyzed by a benchmark IrO_(2)electrocatalyst.The NiFeCo-LDH electrocatalyst greatly improves the kinetics of the AEM alkaline seawater electrolyzer,consequently reducing its activation loss and leading to high performance.Based on the results,this NiFeCo-LDH-catalyzed AEM alkaline seawater electrolyzer can likely surpass the energy conversion targets of the US Department of Energy.
基金financial support from the National Key R&D Program(2023YFE0108000)the Academy of Sciences Project of Guangdong Province(2019GDASYL-0102007,2021GDASYL-20210103063)+1 种基金GDAS’Project of Science and Technology Development(2022GDASZH-2022010203-003)financial support from the China Scholarship Council(202108210128)。
文摘An advantageous porous architecture of electrodes is pivotal in significantly enhancing alkaline water electrolysis(AWE)efficiency by optimizing the mass transport mechanisms.This effect becomes even more pronounced when aiming to achieve elevated current densities.Herein,we employed a rapid and scalable laser texturing process to craft novel multi-channel porous electrodes.Particularly,the obtained electrodes exhibit the lowest Tafel slope of 79 mV dec^(-1)(HER)and 49 mV dec^(-1)(OER).As anticipated,the alkaline electrolyzer(AEL)cell incorporating multi-channel porous electrodes(NP-LT30)exhibited a remarkable improvement in cell efficiency,with voltage drops(from 2.28 to 1.97 V)exceeding 300 mV under 1 A cm^(-1),compared to conventional perforated Ni plate electrodes.This enhancement mainly stemmed from the employed multi-channel porous structure,facilitating mass transport and bubble dynamics through an innovative convection mode,surpassing the traditional convection mode.Furthermore,the NP-LT30-based AEL cell demonstrated exceptional durability for 300 h under 1.0 A cm^(-2).This study underscores the capability of the novel multi-channel porous electrodes to expedite mass transport in practical AWE applications.
基金financial support by the National Natural Science Foundation of China(No.52102241)Doctor of Suzhou University Scientific Research Foundation(Nos.2022BSK019,2020BS015)+2 种基金the Primary Research and Development Program of Anhui Province(No.201904a05020087)the Natural Science Research Project in Universities of Anhui Province in China(Nos.2022AH051386,KJ2021A1114)the Foundation(No.GZKF202211)of State Key Laboratory of Biobased Material and Green Papermaking Qilu University of Technology。
文摘Available online Alkaline water electrolysis(AWE)is a prominent technique for obtaining a sustainable hydrogen source and effectively managing the energy infrastructure.Noble metal-based electrocatalysts,owing to their exceptional hydrogen binding energy,exhibit remarkable catalytic activity and long-term stability in the hydrogen evolution reaction(HER).However,the restricted accessibility and exorbitant cost of noble-metal materials pose obstacles to their extensive adoption in industrial contexts.This review investigates strategies aimed at reducing the dependence on noble-metal electrocatalysts and developing a cost-effective alkaline HER catalyst,while considering the principles of sustainable development.The initial discussion covers the fundamental principle of HER,followed by an overview of prevalent techniques for synthesizing catalysts based on noble metals,along with a thorough examination of recent advancements.The subsequent discussion focuses on the strategies employed to improve noble metalbased catalysts,including enhancing the intrinsic activity at active sites and increasing the quantity of active sites.Ultimately,this investigation concludes by examining the present state and future direction of research in the field of electrocatalysis for the HER.
基金financially supported by the Guangxi Natural Science Fund for Distinguished Young Scholars(No.2024GXNSFFA010008)the Natural Science Foundation of Jilin Province of China(No.20240101098JC)the National Natural Science Foundation of China(No.22469002)。
文摘Establishing an energy-saving and affordable hydrogen production route from infinite seawater presents a promising strategy for achieving carbon neutrality and low-carbon development.Compared with the kinetically sluggish oxygen evolution reaction(OER),the thermodynamically advantageous sulfion oxidation reaction(SOR)enables the S^(2-)pollutants recovery while reducing the energy input of water electrolysis.Here,a nanoporous NiMo alloy ligament(np-NiMo)with AlNi_(3)/Al_(5)Mo heterostructure was prepared for hydrogen evolution reaction(HER,-0.134V versus reversible hydrogen electrode(vs.RHE)at 50mA/cm^(2)),which needs an Al_(89)Ni_(10)Mo_(1)as a precursor and dealloying operation.Further,the np-NiMo alloy was thermal-treated with S powder to generate Mo-doped NiS_(2)(np-NiMo-S)for OER(1.544V vs.RHE at 50mA/cm^(2))and SOR(0.364 V vs.RHE at 50mA/cm^(2)),while still maintaining the nanostructuring advantages.Moreover,for a two-electrode electrolyzer system with np-NiMo cathode(1M KOH+seawater)coupling np-NiMo-S anode(1mol/L KOH+seawater+1 mol/L Na_(2)S),a remarkably ultra-low cell potential of 0.532 V is acquired at 50mA/cm^(2),which is about 1.015 V below that of normal alkaline seawater splitting.The theory calculations confirmed that the AlNi_(3)/Al_(5)Mo heterostructure within np-NiMo promotes H_(2)O dissociation for excellent HER,while the Mo-dopant of np-NiMo-S lowers energy barriers for the rate-determining step from^(*)S_(4)to^(*)S_(8).This work develops two kinds of NiMo alloy with tremendous prominence for achieving energy-efficient hydrogen production from alkaline seawater and sulfur recycling from sulfion-rich sewage.
文摘The hydrogen evolution reaction(HER)in alkaline water electrolysis faces significant kinetic and thermodynamic challenges that hinder its efficiency and scalability for sustainable hydrogen production.Herein,we employed an in-situ synthesis strategy to incorporate H atoms into the PdRu alloy lattice to form H_(Inc)-PdRu electrocatalyst,thereby modulating its electronic structure and enhancing its alkaline HER performance.We demonstrate that the incorporation of H atoms significantly improves electrocatalytic activity,achieving a remarkably low overpotential of 25 mV at 10 mA cm^(-2)compared with the Pd,Ru and PdRu catalysts while maintaining robust catalyst stability.Operando spectroscopic analysis indicates that H insertion into the H_(Inc)-PdRu electrocatalyst enhances the availability of H_(2)O^(*)at the surface,promoting water dissociation at the active sites.Theoretical calculations proposed that the co-incorporating H and Ru atoms induces s-d orbital coupling within the Pd lattices,effectively weakening hydrogen adsorption strength and optimizing the alkaline HER energetics.This work presents a facile approach for the rational design of bimetallic electrocatalysts for efficient and stable alkaline water electrolysis for renewable hydrogen production.
文摘Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchange membrane water electrolysis.Here,homogeneous high entropy oxide(HEO)film is in-situ fabricated on nickel foam(NF)substrate via magnetron sputtering technology without annealing process in air,which is composed of many spinel-structured(FeCoNiCrMo)_(3)O_(4) grains with an average particle size of 2.5 nm.The resulting HEO film(abbreviated as(FeCoNiCr-Mo)_(3)O_(4))exhibits a superior OER performance with a low OER overpotential of 216 mV at 10 mA cm^(–2) and steadily operates at 100 mA cm^(–2) for 200 h with a decay of only 272μV h^(–1),which is far better than that of commercial IrO_(2) catalyst(290 mV,1090μV h^(–1)).Tetramethylammonium cation(TMA^(+))probe experiment,activation energy analysis and theoretical calculations unveil that the OER on(FeCoNiCrMo)_(3)O_(4) follows an adsorbate evolution mechanism pathway,where the energy barrier of rate-determining step for OER on(FeCoNiCrMo)_(3)O_(4) is substantially lowered.Also,methanol molecular probe experiment suggests that a weakened ^(*)OH bonding on the(FeCoNiCrMo)_(3)O_(4) surface and a rapid deprotonation of ^(*)OH,further enhancing its OER performance.This work provides a feasible solution for designing efficient high entropy oxides electrocatalysts for OER,accelerating the practical process of water electrolysis for H2 production.
基金funded by the National Key Research and Development Program of China(2022YFB3803600)the National Natural Science Foundation of China(22368050,22378346)+4 种基金the Key Research and Development Program of Yunnan Province(202302AF080002)Yunnan Basic Applied Research Project(202401AT070460,202401AU070229)Xingdian Talent Support Program Project in Yunnan Province,the Scientific Research Fund Project of Yunnan Education Department(2024J0014,2024J0013)the Open Project of Yunnan Precious Metals Laboratory Co.,Ltd(YPML-2023050259,YPML-2023050260,YPML-20240502008)the Scientific Research and Innovation Project of Postgraduate Students in the Academic Degree of Yunnan University.
文摘The reasonable development and design of high-efficiency and low-cost electrocatalysts for hydrogen evolution reaction(HER)under industrial current densities are imperative for achieving carbon neutrality,while also posing challenges.In this study,an efficient electrocatalyst is successfully constructed through electrodeposition methods,which consists of monodispersed Pt loaded on amorphous/crystalline nickel–iron layered double hydroxide(Pt-SAs/ac-NiFe LDH).The Pt-SAs/ac-NiFe LDH demonstrates an elevated mass activity of 17.66 A mg_(Pt)^(−1)and a significant turnover frequency of 17.90 s^(−1)for HER in alkaline conditions under the overpotential of 100 mV.Meanwhile,for alkaline freshwater and seawater,Pt-SAs/ac-NiFe LDH exhibits ultra-low overpotentials of 141 and 138 mV to reach 1000 mA cm^(−2),respectively.Remarkably,it maintains stable operation for 100 h at 500 mA cm^(−2),showcasing its robustness and reliability.In situ Raman spectra reveal that Pt single atoms(Pt-SAs)accelerate interfacial water dissociation,thereby enhancing the HER kinetics in Pt-SAs/ac-NiFe LDH.Furthermore,theoretical calculation results show significant electronic interaction between the Pt-SAs and the ac-NiFe LDH support.The interaction significantly enhances water adsorption and dissociation,and balances the adsorption/desorption of hydrogen intermediates,ultimately improving HER performance.This research provides a viable method for designing efficient HER catalysts for water electrolysis in alkaline freshwater and seawater under industrial current densities.
文摘Developing effective and practical electrocatalyst under industrial electrolysis conditions is critical for renewable hydrogen production.Herein,we report the self-supporting NiFe LDH-MoS_(x)integrated electrode for water oxidation under normal alkaline test condition(1 M KOH at 25℃)and simulated industrial electrolysis conditions(5 M KOH at 65℃).Such optimized electrode exhibits excellent oxygen evolution reaction(OER)performance with overpotential of 195 and 290 mV at current density of 100 and 400 mA·cm^(-2)under normal alkaline test condition.Notably,only over-potential of 156 and 201 mV were required to achieve the current density of 100 and 400mA·cm^(-2)under simulated industrial electrolysis conditions.No significant degradations were observed after long-term durability tests for both conditions.When using in two-electrode system,the operational voltages of 1.44 and 1.72 V were required to achieve a current density of 10 and 100 mA·cm^(-2)for the overall water splitting test(NiFe LDH-MoS_(x)/INF||20%Pt/C).Additionally,the operational voltage of employing NiFe LDH-MoS_(x)/INF as both cathode and anode merely require 1.52 V at 50mA·cm^(-2)at simulated industrial electrolysis conditions.Notably,a membrane electrode assembly(MEA)for anion exchange membrane water electrolysis(AEMWEs)using NiFe LDH-MoS_(x)/INF as an anode catalyst exhibited an energy conversion efficiency of 71.8%at current density of 400 mA·cm^(-2)in 1 M KOH at 60℃.Further experimental results reveal that sulfurized substrate not only improved the conductivity of NiFe LDH,but also regulated its electronic configurations and atomic composition,leading to the excellent activity.The easy-obtained and cost-effective integrated electrodes are expected to meet the large-scale application of industrial water electrolysis.
基金National Natural Science Foundation of China,Grant/Award Numbers:11974303,12074332Qinglan Project of Jiangsu Province,Grant/Award Number:137050317the Interdisciplinary Research Project of Chemistry Discipline,Grant/Award Number:yzuxk202014 and High‐End Talent Program of Yangzhou University,Grant/Award Number:137080051。
文摘The key challenge of industrial water electrolysis is to design catalytic electrodes that can stabilize high current density with low power consumption(i.e.,overpotential),while industrial harsh conditions make the balance between electrode activity and stability more difficult.Here,we develop an efficient and durable electrode for water oxidation reaction(WOR),which yields a high current density of 1000 mA cm−2 at an overpotential of only 284 mV in 1M KOH at 25°C and shows robust stability even in 6M KOH strong alkali with an elevated temperature up to 80°C.This electrode is fabricated from a cheap nickel foam(NF)substrate through a simple one-step solution etching method,resulting in the growth of ultrafine phosphorus doped nickel-iron(oxy)hydroxide[P-(Ni,Fe)O_(x)H_(y)]nanoparticles embedded into abundant micropores on the surface,featured as a self-stabilized catalyst–substrate fusion electrode.Such self-stabilizing effect fastens highly active P-(Ni,Fe)O_(x)H_(y)species on conductive NF substrates with significant contribution to catalyst fixation and charge transfer,realizing a win–win tactics for WOR activity and durability at high current densities in harsh environments.This work affords a cost-effective WOR electrode that can well work at large current densities,suggestive of the rational design of catalyst electrodes toward industrial-scale water electrolysis.
基金supported by the National Natural Science Foundation of China(No.51902232)。
文摘Design of the catalyst for efficient water dissociation and hydrogen recombination is paramount in enhancement of the alkaline water electrolysis kinetics.Herein,we reported a delicate hierarchical(VO)_(2) P_(2)O_(7)-Ni_(2) P@NF(VPO-Ni_(2) P@NF)hybrid catalyst that operated efficiently in alkaline media.The VPO and Ni_(2) P respectively act as the water dissociation promoter and the hydrogen recombination center,which synergistically propel water adsorption/dissociation and H intermediates recombination.The resulting synergistic interfaces between VPO and Ni_(2) P are verified to afford the catalyst an outstanding performance for hydrogen evolution reaction in alkaline media with an overpotential of 154 mV at 10 mA cm^(-2),Tafel slope of 65 mV dec^(-1),and remarkable durability.Furthermore,the catalyst presents the potential for overall water splitting.This work may shed fresh light on the high-performance electrocatalyst design and the application of VPO on water electrolysis.
基金financially supported by the National Natural Science Foundation of China(Nos.22375005,22103054 and 22173066)the Natural Science Research Project of Anhui Province Education Department(No.2022AH050323)+3 种基金the Foundation of Key Laboratory of Advanced Technique&Preparation for Renewable Energy Materials,Ministry of Education,Yunnan Normal University(No.OF2022-05)partly supported by Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘Highly efficient hydrogen evolution reaction(HER)electrocatalysts play a crucial part in generating green hydrogen.Herein,an electrochemical activation approach was applied to design 6.7 Rh-Ni_(2)P-800CV electrocatalysts in alkaline electrolytes.The results confirm that the generation of metal oxide sites through the electrochemical activation strategy can effectively improve the intrinsic activity of 6.7 Rh-Ni_(2)P-800CV.The density functional calculations further confirm that metal oxide active sites are favorable for H2O adsorption and activation and H*adsorption/desorption.The 6.7 Rh-Ni_(2)P-800CV possesses significantly enhanced HER performance with low overpotential(25 mV at 10 mA·cm^(2)),small Tafel(60 mV·dec^(-1))and robust stability in 1.0 M KOH,outperforming Pt/C and 6.7 Rh-Ni_(2)P counterparts.Meanwhile,6.7 Rh-Ni_(2)P-800CV can even operate at a large current density(550 mA·cm^(-2))up to 90 h with an overpotential of 320 mV,which meets the requirements of industrial water splitting.What's more,the overall watersplitting systems(6.7 Rh-Ni_(2)P-800CV‖6.7 Rh-Ni_(2)P-800CV)can be directly driven by the solar cell.This work highlights that electrochemical activation technology provides a robust avenue toward constructing efficient electrocatalysts for sustainable energy conversion.
基金Fraunhofer-Gesellschaft,Grant/Award Number:097-602175Ministry of Culture and Science of the State of North Rhine-Westphalia,Grant/Award Number:Mat4Hy+2 种基金Mercator Research Center Ruhr,Grant/Award Numbers:Ex-2021-0034,Ko-2021-0016Bundesministerium für Bildung und Forschung,Grant/Award Number:03XP0263Deutsche Forschungsgemeinschaft,Grant/Award Number:CRC/TRR 247。
文摘Despite considerable efforts to develop electrolyzers for energy conversion,progress has been hindered during the implementation stage by different catalyst development requirements in academic and industrial research.Herein,a coherent workflow for the efficient transition of electrocatalysts from basic research to application readiness for the alkaline oxygen evolution reaction is proposed.To demonstrate this research approach,La_(0.8)Sr_(0.2)CoO_(3) is selected as a catalyst,and its electrocatalytic performance is compared with that of the benchmark material NiFe_(2)O_(4).The La_(0.8)Sr_(0.2)CoO_(3) catalyst with the desired dispersity is successfully synthesized by scalable spray-flame synthesis.Subsequently,inks are formulated using different binders(Nafion^(®),Naf;Sustainion^(®),Sus),and nickel substrates are spray coated,ensuring a homogeneous catalyst distribution.Extensive electrochemical evaluations,including several scale-bridging techniques,highlight the efficiency of the La_(0.8)Sr_(0.2)CoO_(3) catalyst.Experiments using the scanning droplet cell(SDC)indicate good lateral homogeneity for La_(0.8)Sr_(0.2)CoO_(3) electrodes and NiFe_(2)O_(4)-Sus,while the NiFe_(2)O_(4)-Naf film suffers from delamination.Among the various half-cell techniques,SDC proves to be a valuable tool to quickly check whether a catalyst layer is suitable for full-cell-level testing and will be used for the fast-tracking of catalysts in the future.Complementary compression and flow cell experiments provide valuable information on the electrodes'behavior upon exposure to chemical and mechanical stress.Finally,parameters and conditions simulating industrial settings are applied using a zero-gap cell.Findings from various research fields across different scales obtained based on the developed coherent workflow contribute to a better understanding of the electrocatalytic system at the early stages of development and provide important insights for the evaluation of novel materials that are to be used in large-scale industrial applications.
基金financially supported by the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(No.NY223016)Qinglan Project of Jiangsu Province of China2024 Nanjing Science and Technology Innovation Program(No.NJKCZYZZ2024-06)。
文摘With the in-depth implementation of sustainable development strategies,hydrogen energy as a clean energy source is receiving increasing attention[1,2].Among the various methods of hydrogen production,the electrocatalytic decomposition of abundant seawater into hydrogen utilizing renewable energy has emerged as a green and promising approach.However,natural seawater contains complex components,such as halide ions,which lead to the corrosion of catalysts or the occurrence of competitive side reactions during the electrolysis process[3].
