Anion-exchange membrane water electrolyzers(AEMWEs)for green hydrogen production have received intensive attention due to their feasibility of using earth-abundant NiFe-based catalysts.By introducing a third metal int...Anion-exchange membrane water electrolyzers(AEMWEs)for green hydrogen production have received intensive attention due to their feasibility of using earth-abundant NiFe-based catalysts.By introducing a third metal into NiFe-based catalysts to construct asymmetrical M-NiFe units,the d-orbital and electronic structures can be adjusted,which is an important strategy to achieve sufficient oxygen evolution reaction(OER)performance in AEMWEs.Herein,the ternary NiFeM(M:La,Mo)catalysts featured with distinct M-NiFe units and varying d-orbitals are reported in this work.Experimental and theoretical calculation results reveal that the doping of La leads to optimized hybridization between d orbital in NiFeM and 2p in oxygen,resulting in enhanced adsorption strength of oxygen intermediates,and reduced rate-determining step energy barrier,which is responsible for the enhanced OER performance.More critically,the obtained NiFeLa catalyst only requires 1.58 V to reach 1 A cm^(−2) in an anion exchange membrane electrolyzer and demonstrates excellent long-term stability of up to 600 h.展开更多
Designing highly active and stable electrocatalysts of oxygen evolution reaction(OER)is one of the crucial challenges.In this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium(Rh@NiFe-MIL-5...Designing highly active and stable electrocatalysts of oxygen evolution reaction(OER)is one of the crucial challenges.In this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium(Rh@NiFe-MIL-53),is successfully prepared via the hydrothermal method.In-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active species.More importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe(OH)_(2)after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@NiFeOOH.Furthermore,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center(εd),accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining steps.Consequently,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity(240 mV)with a small Tafel slope of 48.2 mV dec^(-1)and long-term durability(over1270 h at 10 m A cm^(-2)and 110 h at 200 mA cm^(-2)).This work presents a new perspective on designing highly efficient OER electrocatalysts.展开更多
Catalyst–support interaction plays a crucial role in improving the catalytic activity of oxygen evolution reaction(OER).Here we modulate the catalyst–support interaction in polyaniline-supported Ni_(3)Fe oxide(Ni_(3...Catalyst–support interaction plays a crucial role in improving the catalytic activity of oxygen evolution reaction(OER).Here we modulate the catalyst–support interaction in polyaniline-supported Ni_(3)Fe oxide(Ni_(3)Fe oxide/PANI)with a robust hetero-interface,which significantly improves oxygen evolution activities with an overpotential of 270 mV at 10 mA cm^(-2)and specific activity of 2.08 mA cm_(ECSA)^(-2)at overpotential of 300 mV,3.84-fold that of Ni_(3)Fe oxide.It is revealed that the catalyst–support interaction between Ni_(3)Fe oxide and PANI support enhances the Ni–O covalency via the interfacial Ni–N bond,thus promoting the charge and mass transfer on Ni_(3)Fe oxide.Considering the excellent activity and stability,rechargeable Zn-air batteries with optimum Ni_(3)Fe oxide/PANI are assembled,delivering a low charge voltage of 1.95 V to cycle for 400 h at 10 mA cm^(-2).The regulation of the effect of catalyst–support interaction on catalytic activity provides new possibilities for the future design of highly efficient OER catalysts.展开更多
High efficiency,cost-effective and durable electrocatalysts are of pivotal importance in energy conversion and storage systems.The electro-oxidation of water to oxygen plays a crucial role in such energy conversion te...High efficiency,cost-effective and durable electrocatalysts are of pivotal importance in energy conversion and storage systems.The electro-oxidation of water to oxygen plays a crucial role in such energy conversion technologies.Herein,we report a robust method for the synthesis of a bimetallic alkoxide for efficient oxygen evolution reaction(OER)for alkaline electrolysis,which yields current density of 10 mA cm^(-2)at an overpotential of 215 mV in 0.1 M KOH electrolyte.The catalyst demonstrates an excellent durability for more than 540 h operation with negligible degradation in activity.Raman spectra revealed that the catalyst underwent structure reconstruction during OER,evolving into oxyhydroxide,which was the active site proceeding OER in alkaline electrolyte.In-situ synchrotron X-ray absorption experiment combined with density functional theory calculation suggests a lattice oxygen involved electrocatalytic reaction mechanism for the in-situ generated nickel–iron bimetal-oxyhydroxide catalyst.This mechanism together with the synergy between nickel and iron are responsible for the enhanced catalytic activity and durability.These findings provide promising strategies for the rational design of nonnoble metal OER catalysts.展开更多
The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct ...The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER.展开更多
Binary composites(ZIF-67/rGO)were synthesized by one-step precipitation method using cobalt nitrate hexahydrate as metal source,2-methylimidazole as organic ligand,and reduced graphene oxide(rGO)as carbon carrier.Then...Binary composites(ZIF-67/rGO)were synthesized by one-step precipitation method using cobalt nitrate hexahydrate as metal source,2-methylimidazole as organic ligand,and reduced graphene oxide(rGO)as carbon carrier.Then Ru3+was introduced for ion exchange,and the porous Ru-doped Co_(3)O_(4)/rGO(Ru-Co_(3)O_(4)/rGO)composite electrocatalyst was prepared by annealing.The phase structure,morphology,and valence state of the catalyst were analyzed by X-ray powder diffraction(XRD),scanning electron microscope(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).In 1 mol·L^(-1)KOH,the oxygen evolution reaction(OER)performance of the catalyst was measured by linear sweep voltammetry,cyclic voltammetry,and chronoamperometry.The results show that the combination of Ru doping and rGO provides a fast channel for collaborative electron transfer.At the same time,rGO as a carbon carrier can improve the electrical conductivity of Ru-Co_(3)O_(4)particles,and the uniformly dispersed nanoparticles enable the reactants to diffuse freely on the catalyst.The results showed that the electrochemical performance of Ru-Co_(3)O_(4)/rGO was much better than that of Co_(3)O_(4)/rGO,and the overpotential of Ru-Co_(3)O_(4)/rGO was 363.5 mV at the current density of 50 mA·cm^(-2).展开更多
Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will ben...Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will benefit their quick transition to the next catalysts.Herein,Mo-doped CoOOH was designed as a high-performance model electrocatalyst with durability for 20 h at 10 mAcm−2.Additionally,it had an overpotential of 260 mV(glassy carbon)or 215 mV(nickel foam),which was 78 mV lower than that of IrO_(2)(338 mV).In situ,Raman spectroscopy revealed the transformation process of CoOOH.Calculations using the density functional theory showed that during OER,doped Mo increased the spin-up density of states and shrank the spin-down bandgap of the 3d orbits in the reconstructed CoOOH under the electrochemical activation process,which simultaneously optimized the adsorption and electron conduction of oxygen-related intermediates on Co sites and lowered the OER overpotentials.Our research provides new insights into the methodical planning of the creation of transition-metal oxyhydroxide OER catalysts.展开更多
Electricity-driven water splitting to produce hydrogen is one of the most efficient ways to alleviate energy crisis and environmental pollution problems,in which the anodic oxygen evolution reaction(OER)is the key hal...Electricity-driven water splitting to produce hydrogen is one of the most efficient ways to alleviate energy crisis and environmental pollution problems,in which the anodic oxygen evolution reaction(OER)is the key half-reaction of performance-limiting in water splitting.Given the complicated reaction process and surface reconstruction of the involved catalysts under actual working conditions,unraveling the real active sites,probing multiple reaction intermediates and clarifying catalytic pathways through in-situ characterization techniques and theoretical calculations are essential.In this review,we summarize the recent advancements in understanding the catalytic process,unlocking the water oxidation active phase and elucidating catalytic mechanism of water oxidation by various in-situ characterization techniques.Firstly,we introduce conventionally proposed traditional catalytic mechanisms and novel evolutionary mechanisms of OER,and highlight the significance of optimal catalytic pathways and intrinsic stability.Next,we provide a comprehensive overview of the fundamental working principles,different detection modes,applicable scenarios,and limitations associated with the in-situ characterization techniques.Further,we exemplified the in-situ studies and discussed phase transition detection,visualization of speciation evolution,electronic structure tracking,observation of reaction active intermediates,and monitoring of catalytic products,as well as establishing catalytic structure-activity relationships and catalytic mechanism.Finally,the key challenges and future perspectives for demystifying the water oxidation process are briefly proposed.展开更多
High-entropy(HE)design provides ample opportunities for accessing catalysts with unique physiochemical properties for advanced energy and environmental applications.Although a variety of multi-cationic high-entropy ma...High-entropy(HE)design provides ample opportunities for accessing catalysts with unique physiochemical properties for advanced energy and environmental applications.Although a variety of multi-cationic high-entropy materials(HEMs)have been identified,HEMs consisted of multiple cationic and anionic elements are still limited.Herein,we present the design and synthesis of a series of rutile-structured high-entropy oxy fluorides(HEOFs),including[RuO_(2)]x[MgMnZnCoF_(2)]y,[MnO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[MoO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[SnO_(2)]_(x)[MgMnZnCoF_(2)]_(y)and[TiO_(2)]_(x)[MgMnZnCoF_(2)]_(y)(x:y=3:1,2:1,1:1).All the HEOFs are obtained through mechanochemical alloying rutile-structured oxide and fluoride precursors and the HEOFs inherit the crystal structures of the skeleton oxides.Moreover,the HEOFs exhibit enhanced electrocatalytic oxygen evolution reaction(OER)activity than the corresponding oneelement precursors.Typically,the best-performed HEOF[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)catalyst requires an overpotential of 240 mV to achieve a current density of 10 mA cm^(-2),which is lower than RuO_(2)(291 mV),More impressively,the specific mass activity of[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)is 537.1 A g_(Ru)^(-1)at1.55 V(vs RHE),which is ca.7.6 times that of RuO_(2)(70.5 A g_(Ru)^(-1)).The enhanced electrocata lytic OER performance obtained on[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)is ascribed to the contribution of the different cationic and anionic elements that modulates the electronic structures of the pristine RuO_(2),which facilitates efficient OER kinetics.This work demonstrates the efficacy of high-entropy design towards approaching excellent catalysts for enhanced electrocatalysis.展开更多
Transition metal-based nanomaterials have emerged as promising electrocatalysts for oxygen evolution reaction(OER).Considerable research efforts have shown that self-reconstruction occurs on these nanomaterials under ...Transition metal-based nanomaterials have emerged as promising electrocatalysts for oxygen evolution reaction(OER).Considerable research efforts have shown that self-reconstruction occurs on these nanomaterials under operating conditions of OER process.However,most of them undergo incomplete reconstruction with limited thickness of reconstruction layer,leading to low component utilization and arduous exploration of real catalytic mechanism.Herein,we identify the dynamic behaviors in complete reconstruction of Co-based complexes during OER.The hollow phytic acid(PA)cross-linked CoFe-based complex nanoboxes with porous nanowalls are designed because of their good electrolyte penetration and mass transport ability,in favor of the fast and complete reconstruction.A series of experiment characterizations demonstrate that the reconstruction process includes the fast substitution of PA by OH-to form Co(Fe)(OH)xand subsequent potential-driven oxidation to Co(Fe)OOH.The obtained CoFeOOH delivers a low overpotential of 290 mV at a current density of 10 mA cm^(-2)and a long-term stability.The experiment results together with theory calculations reveal that the Fe incorporation can result in the electron rearrangement of reconstructed CoFeOOH and optimization of their electronic structure,accounting for the enhanced OER activity.The work provides new insights into complete reconstruction of metal-based complexes during OER and offers guidelines for rational design of high-performance electrocatalysts.展开更多
Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy...Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy is reported here,which has been proven to be effective in preparing highly active electrocatalyst.For example,the cobalt,sulfur,and phosphorus modulated nickel hydroxide(denoted as NiCoPSOH)only needs an overpotential of 232 mV to reach a current density of 20 mA cm^(–2),demonstrating excellent OER performances.The cation and anion modulation facilitates the generation of high-valent Ni species,which would activate the lattice oxygen and switch the OER reaction pathway from conventional adsorbate evolution mechanism to lattice oxygen mechanism(LOM),as evidenced by the results of electrochemical measurements,Raman spectroscopy and differential electrochemical mass spectrometry.The LOM pathway of NiCoPSOH is further verified by the theoretical calculations,including the upshift of O 2p band center,the weakened Ni–O bond and the lowest energy barrier of rate-limiting step.Thus,the anion and cation modulated catalyst NiCoPSOH could effectively accelerate the sluggish OER kinetics.Our work provides a new insight into the cation and anion modulation,and broadens the possibility for the rational design of highly active electrocatalysts.展开更多
Developing highly active oxygen evolution reaction(OER)electrocatalysts with robust durability is essential in producing high-purity hydrogen through water electrolysis.Layered double hydroxide(LDH)based catalysts hav...Developing highly active oxygen evolution reaction(OER)electrocatalysts with robust durability is essential in producing high-purity hydrogen through water electrolysis.Layered double hydroxide(LDH)based catalysts have demonstrated efficient catalytic performance toward the relatively sluggish OER.By considering the promotion effect of phosphate(Pi)on proton transfer,herein,a facile phosphate acid(PA)surface-neutralization strategy is developed to in-situ construct NiCo-LDH/NiCoPi hetero-sheets toward OER catalysis.OER activity of NiCoLDH is significantly boosted due to the proton promotion effect and the electronic modulation effect of NiCoPi.As a result,the facilely prepared NiCo-LDH/NiCoPi catalyst displays superior OER catalytic activity with a low overpotential of 300 mV to deliver 100 mA cm^(-2)OER and a Tafel slope of 73 mV dec^(-1).Furthermore,no visible activity decay is detected after a 200-h continuous OER operation.The present work,therefore,provides a promising strategy to exploit robust OER electrocatalysts for commercial water electrolysers.展开更多
Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electr...Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge.Here,an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide(CoMoO_(4)/Co_(3)O_(4)@CC)in a favorable direction to improve the OER performance.Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching,with the formation of a dynamically stable amorphous-crystalline heterostructure.Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co_(3)O_(4) are crucial in enhancing the catalytic performance.Consequently,the reconstructed CoMoO_(4)/Co_(3)O_(4)@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm^(-2) in 1 M KOH,and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices,achieving ultra-long stability for over 500 and 1200 h,respectively.This work provides a promising route for the construction of high-performance electrocatalysts.展开更多
Two-dimensional transition metal carbides(MXenes) have been demonstrated to be promising supports for single-atom catalysts(SACs) to enable efficient oxygen evolution reaction(OER).However,the rational design of MXene...Two-dimensional transition metal carbides(MXenes) have been demonstrated to be promising supports for single-atom catalysts(SACs) to enable efficient oxygen evolution reaction(OER).However,the rational design of MXene-based SACs depends on an experimental trial-and-error approach.A theoretical guidance principle is highly expected for the efficient evaluation of MXene-based SACs.Herein,highthroughput screening was performed through first-principles calculations and machine learning techniques.Ti_(3)C_(2)(OH)_(x),V_(3)C_(2)(OH)_(x),Zr_(3)C_(2)(OH)_(x),Nb_(3)C_(2)(OH)_(x),Hf_(3)C_(2)(OH)_(x),Ta_(3)C_(2)(OH)_(x),and W_(3)C_(2)(OH)_(x) were screened out based on their excellent stability.Zn,Pd,Ag,Cd,Au,and Hg were proposed to be promising single atoms anchored in MXenes based on cohesive energy analysis.Hf_(3)C_(2)(OH)_(x) with a Pd single atom delivers a theoretical overpotential of 81 mV.Both moderate electron-deficient state and high covalency of metal-carbon bonds were critical features for the high OER reactivity.This principle is expected to be a promising approach to the rational design of OER catalysts for metal-air batteries,fuel cells,and other OER-based energy storage devices.展开更多
The design of cost-effective electrocatalysts is an open challenging for oxygen evolution reaction(OER)due to the“stable-oractive”dilemma.Zirconium dioxide(ZrO_(2)),a versatile and low-cost material that can be stab...The design of cost-effective electrocatalysts is an open challenging for oxygen evolution reaction(OER)due to the“stable-oractive”dilemma.Zirconium dioxide(ZrO_(2)),a versatile and low-cost material that can be stable under OER operating conditions,exhibits inherently poor OER activity from experimental observations.Herein,we doped a series of metal elements to regulate the ZrO_(2)catalytic activity in OER via spin-polarized density functional theory calculations with van der Waals interactions.Microkinetic modeling as a function of the OER activity descriptor(G_(O*)-G_(HO*))displays that 16 metal dopants enable to enhance OER activities over a thermodynamically stable ZrO_(2)surface,among which Fe and Rh(in the form of single-atom dopant)reach the volcano peak(i.e.the optimal activity of OER under the potential of interest),indicating excellent OER performance.Free energy diagram calculations,density of states,and ab initio molecular dynamics simulations further showed that Fe and Rh are the effective dopants for ZrO_(2),leading to low OER overpotential,high conductivity,and good stability.Considering cost-effectiveness,single-atom Fe doped ZrO_(2)emerged as the most promising catalyst for OER.This finding offers a valuable perspective and reference for experimental researchers to design cost-effective catalysts for the industrial-scale OER production.展开更多
The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER...The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER is a four-step,four-electron reaction,and its slow kinetics result in high overpotentials,posing a challenge.To address this issue,numerous strategies involving modified catalysts have been proposed and proven to be highly efficient.In these strategies,the introduction of strain has been widely reported because it is generally believed to effectively regulate the electronic structure of metal sites and alter the adsorption energy of catalyst surfaces with reaction intermediates.However,strain has many other effects that are not well known,making it an important yet unexplored area.Based on this,this review provides a detailed introduction to the various roles of strain in OER.To better explain these roles,the review also presents the definition of strain and elucidates the potential mechanisms of strain in OER based on the d-band center theory and adsorption volcano plot.Additionally,the review showcases various ways of introducing strain in OER through examples reported in the latest literature,aiming to provide a comprehensive perspective for the development of strain engineering.Finally,the review analyzes the appropriate proportion of strain introduction,compares compressive and tensile strain,and examines the impact of strain on stability.And the review offers prospects for future research directions in this emerging field.展开更多
N-doped carbon materials,with their applications as electrocatalysts for the oxygen reduction reaction(ORR),have been extensively studied.However,a negletcted fact is that the operating potential of the ORR is higher ...N-doped carbon materials,with their applications as electrocatalysts for the oxygen reduction reaction(ORR),have been extensively studied.However,a negletcted fact is that the operating potential of the ORR is higher than the theoretical oxida-tion potential of carbon,possibly leading to the oxidation of carbon materials.Consequently,the infl uence of the structural oxidation evolution on ORR performance and the real active sites are not clear.In this study,we discover a two-step oxida-tion process of N-doped carbon during the ORR.The fi rst oxidation process is caused by the applied potential and bubbling oxygen during the ORR,leading to the oxidative dissolution of N and the formation of abundant oxygen-containing functional groups.This oxidation process also converts the reaction path from the four-electron(4e)ORR to the two-electron(2e)ORR.Subsequently,the enhanced 2e ORR generates oxidative H_(2)O_(2),which initiates the second stage of oxidation to some newly formed oxygen-containing functional groups,such as quinones to dicarboxyls,further diversifying the oxygen-containing functional groups and making carboxyl groups as the dominant species.We also reveal the synergistic eff ect of multiple oxygen-containing functional groups by providing additional opportunities to access active sites with optimized adsorption of OOH*,thus leading to high effi ciency and durability in electrocatalytic H_(2)O_(2) production.展开更多
The dynamic adsorption of possible intermediates on single-atom catalysts(SACs)under working condition plays a key role in the electrocatalytic performance by the oxygen evolution reaction(OER),and therefore the perfo...The dynamic adsorption of possible intermediates on single-atom catalysts(SACs)under working condition plays a key role in the electrocatalytic performance by the oxygen evolution reaction(OER),and therefore the performance of the dynamic adsorption should be fully considered in the theoretical screening of potential SACs.Based on density functional theory calculations,the OER performance of 27 types of C_(2)N-supported single transition metal atoms(TM@C_(2)N)is systematically investigated without and with considering the dynamic adsorption of possible intermediates.Without considering dynamic adsorption,only Rh@C_(2)N and Ni@C_(2)N are screened out as good catalysts.However,by further considering the dynamic adsorption configurations of possible intermediates,more promising TM@C_(2)N SACs including Fe(Co,Ni,Ru,Rh,Ir)@C_(2)N toward the OER are screened out.The presence of the intermediates(*HO,*O)on SACs could shift their d band center toward lower energy level,which makes the interaction between the adsorbate and SACs moderate and thus enhances their OER performance.The present work is instructive for further screening and designing of efficient single-atom catalysts for the oxygen evolution reaction.展开更多
Ni^(2+)/Cu^(2+)/SO_(4)^(2-)/polyvinyl alcohol precursor fibers with uniform diameters were prepared through electrospinning.Nickel-based composite nanoalloys containing Ni,Cu,and S were prepared through heat treatment...Ni^(2+)/Cu^(2+)/SO_(4)^(2-)/polyvinyl alcohol precursor fibers with uniform diameters were prepared through electrospinning.Nickel-based composite nanoalloys containing Ni,Cu,and S were prepared through heat treatment in an Ar atmosphere.The experimental results show that the main components of the prepared nanoalloys are NiCu,Ni_(3)S_(2),Ni,and C.The nanoalloys exhibit fine grain sizes about 200-500 nm,which can increase with increasing heat treatment temperature.Electrochemical test results show that the nickel sulfidemodified NiCu nanoalloy composites exhibit excellent oxygen evolution reaction properties,and the oxygen evolution reaction properties gradually improve with the increasing heat treatment temperature.The sample prepared at 1 000℃ for 40 min show a low overpotential of 423 mV and a small Tafel slope of 134 mV·dec^(-1) at a current density of 10 mA·cm^(-2).展开更多
Electrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon emission.However,the sluggish kinetics of oxygen evolution reaction on the anode side ...Electrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon emission.However,the sluggish kinetics of oxygen evolution reaction on the anode side of the watersplitting device significantly hinders its practical applications.Generally,the efficiency of oxygen evolution processes depends greatly on the availability of cost‐effective catalysts with high activity and selectivity.In recent years,extensive theoretical and experimental studies have demonstrated that cobalt(Co)‐based nanomaterials,especially low‐dimensional Co‐based nanomaterials with a huge specific surface area and abundant unsaturated active sites,have emerged as versatile electrocatalysts for oxygen evolution reactions,and thus,great progress has been made in the rational design and synthesis of Co‐based nanomaterials for electrocatalytic oxygen evolution reactions.Considering the remarkable progress in this area,in this timely review,we highlight the most recent developments in Co‐based nanomaterials relating to their dimensional control,defect regulation(conductivity),electronic structure regulation,and so forth.Furthermore,a brief conclusion about recent progress achieved in oxygen evolution on Co‐based nanomaterials,as well as an outlook on future research challenges,is given.展开更多
基金financially supported by the National Natural Science Foundation of China(22309137,22279095)Open subject project State Key Laboratory of New Textile Materials and Advanced Processing Technologies(FZ2023001).
文摘Anion-exchange membrane water electrolyzers(AEMWEs)for green hydrogen production have received intensive attention due to their feasibility of using earth-abundant NiFe-based catalysts.By introducing a third metal into NiFe-based catalysts to construct asymmetrical M-NiFe units,the d-orbital and electronic structures can be adjusted,which is an important strategy to achieve sufficient oxygen evolution reaction(OER)performance in AEMWEs.Herein,the ternary NiFeM(M:La,Mo)catalysts featured with distinct M-NiFe units and varying d-orbitals are reported in this work.Experimental and theoretical calculation results reveal that the doping of La leads to optimized hybridization between d orbital in NiFeM and 2p in oxygen,resulting in enhanced adsorption strength of oxygen intermediates,and reduced rate-determining step energy barrier,which is responsible for the enhanced OER performance.More critically,the obtained NiFeLa catalyst only requires 1.58 V to reach 1 A cm^(−2) in an anion exchange membrane electrolyzer and demonstrates excellent long-term stability of up to 600 h.
基金Natural Science Foundation of China(Grant No.NSFC-22072062,22202098)。
文摘Designing highly active and stable electrocatalysts of oxygen evolution reaction(OER)is one of the crucial challenges.In this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium(Rh@NiFe-MIL-53),is successfully prepared via the hydrothermal method.In-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active species.More importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe(OH)_(2)after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@NiFeOOH.Furthermore,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center(εd),accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining steps.Consequently,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity(240 mV)with a small Tafel slope of 48.2 mV dec^(-1)and long-term durability(over1270 h at 10 m A cm^(-2)and 110 h at 200 mA cm^(-2)).This work presents a new perspective on designing highly efficient OER electrocatalysts.
基金Research Institute for Smart Energy(CDB2)the grant from the Research Institute for Advanced Manufacturing(CD8Z)+4 种基金the grant from the Carbon Neutrality Funding Scheme(WZ2R)at The Hong Kong Polytechnic Universitysupport from the Hong Kong Polytechnic University(CD9B,CDBZ and WZ4Q)the National Natural Science Foundation of China(22205187)Shenzhen Municipal Science and Technology Innovation Commission(JCYJ20230807140402006)Start-up Foundation for Introducing Talent of NUIST and Natural Science Foundation of Jiangsu Province of China(BK20230426).
文摘Catalyst–support interaction plays a crucial role in improving the catalytic activity of oxygen evolution reaction(OER).Here we modulate the catalyst–support interaction in polyaniline-supported Ni_(3)Fe oxide(Ni_(3)Fe oxide/PANI)with a robust hetero-interface,which significantly improves oxygen evolution activities with an overpotential of 270 mV at 10 mA cm^(-2)and specific activity of 2.08 mA cm_(ECSA)^(-2)at overpotential of 300 mV,3.84-fold that of Ni_(3)Fe oxide.It is revealed that the catalyst–support interaction between Ni_(3)Fe oxide and PANI support enhances the Ni–O covalency via the interfacial Ni–N bond,thus promoting the charge and mass transfer on Ni_(3)Fe oxide.Considering the excellent activity and stability,rechargeable Zn-air batteries with optimum Ni_(3)Fe oxide/PANI are assembled,delivering a low charge voltage of 1.95 V to cycle for 400 h at 10 mA cm^(-2).The regulation of the effect of catalyst–support interaction on catalytic activity provides new possibilities for the future design of highly efficient OER catalysts.
基金the staff at Beamline (BL08U1-A and BL11B)of the Shanghai Synchrotron Radiation Facility (SSRF)the support from the National Key Research&Development Program of China (2022YFB3803700)+2 种基金the National Natural Science Foundation of China (52171186)the support through the Overseas Outstanding Youth Fund and Shanghai Pujiang Talent Project (21PJ1408500)the financial support from the Center of Hydrogen Science,Shanghai Jiao Tong University。
文摘High efficiency,cost-effective and durable electrocatalysts are of pivotal importance in energy conversion and storage systems.The electro-oxidation of water to oxygen plays a crucial role in such energy conversion technologies.Herein,we report a robust method for the synthesis of a bimetallic alkoxide for efficient oxygen evolution reaction(OER)for alkaline electrolysis,which yields current density of 10 mA cm^(-2)at an overpotential of 215 mV in 0.1 M KOH electrolyte.The catalyst demonstrates an excellent durability for more than 540 h operation with negligible degradation in activity.Raman spectra revealed that the catalyst underwent structure reconstruction during OER,evolving into oxyhydroxide,which was the active site proceeding OER in alkaline electrolyte.In-situ synchrotron X-ray absorption experiment combined with density functional theory calculation suggests a lattice oxygen involved electrocatalytic reaction mechanism for the in-situ generated nickel–iron bimetal-oxyhydroxide catalyst.This mechanism together with the synergy between nickel and iron are responsible for the enhanced catalytic activity and durability.These findings provide promising strategies for the rational design of nonnoble metal OER catalysts.
基金supported by the Taishan Scholar Program of Shandong Province,China (tsqn202211162)the National Natural Science Foundation of China (22102079)the Natural Science Foundation of Shandong Province of China (ZR2021YQ10,ZR2022QB163)。
文摘The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER.
文摘Binary composites(ZIF-67/rGO)were synthesized by one-step precipitation method using cobalt nitrate hexahydrate as metal source,2-methylimidazole as organic ligand,and reduced graphene oxide(rGO)as carbon carrier.Then Ru3+was introduced for ion exchange,and the porous Ru-doped Co_(3)O_(4)/rGO(Ru-Co_(3)O_(4)/rGO)composite electrocatalyst was prepared by annealing.The phase structure,morphology,and valence state of the catalyst were analyzed by X-ray powder diffraction(XRD),scanning electron microscope(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).In 1 mol·L^(-1)KOH,the oxygen evolution reaction(OER)performance of the catalyst was measured by linear sweep voltammetry,cyclic voltammetry,and chronoamperometry.The results show that the combination of Ru doping and rGO provides a fast channel for collaborative electron transfer.At the same time,rGO as a carbon carrier can improve the electrical conductivity of Ru-Co_(3)O_(4)particles,and the uniformly dispersed nanoparticles enable the reactants to diffuse freely on the catalyst.The results showed that the electrochemical performance of Ru-Co_(3)O_(4)/rGO was much better than that of Co_(3)O_(4)/rGO,and the overpotential of Ru-Co_(3)O_(4)/rGO was 363.5 mV at the current density of 50 mA·cm^(-2).
基金The National Natural Science Foundation of China(Grant Nos.52072114 and 51922008)the 111 Project(Grant No.D17007),the Henan Center for Outstanding Overseas Scientists(Grant No.GZS2018003)+2 种基金Xinxiang Major Science and Technology Projects(Grant No.21ZD001)Guangdong Innovative and Entrepreneurial Research Team Program(2016ZT06N500)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)all provided financial support for this work.
文摘Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will benefit their quick transition to the next catalysts.Herein,Mo-doped CoOOH was designed as a high-performance model electrocatalyst with durability for 20 h at 10 mAcm−2.Additionally,it had an overpotential of 260 mV(glassy carbon)or 215 mV(nickel foam),which was 78 mV lower than that of IrO_(2)(338 mV).In situ,Raman spectroscopy revealed the transformation process of CoOOH.Calculations using the density functional theory showed that during OER,doped Mo increased the spin-up density of states and shrank the spin-down bandgap of the 3d orbits in the reconstructed CoOOH under the electrochemical activation process,which simultaneously optimized the adsorption and electron conduction of oxygen-related intermediates on Co sites and lowered the OER overpotentials.Our research provides new insights into the methodical planning of the creation of transition-metal oxyhydroxide OER catalysts.
基金support from National Natural Science Foundation of China(Grant Nos.22125903,22209174)the National Key R&D Program of China(Grants 2022YFA1504100)+2 种基金Dalian Innovation Support Plan for High Level Talents(2019RT09)Dalian National Laboratory For Clean Energy(DNL),CAS,DNL Cooperation Fund,CAS(DNL202016,DNL202019)DICP(DICP I2020032).
文摘Electricity-driven water splitting to produce hydrogen is one of the most efficient ways to alleviate energy crisis and environmental pollution problems,in which the anodic oxygen evolution reaction(OER)is the key half-reaction of performance-limiting in water splitting.Given the complicated reaction process and surface reconstruction of the involved catalysts under actual working conditions,unraveling the real active sites,probing multiple reaction intermediates and clarifying catalytic pathways through in-situ characterization techniques and theoretical calculations are essential.In this review,we summarize the recent advancements in understanding the catalytic process,unlocking the water oxidation active phase and elucidating catalytic mechanism of water oxidation by various in-situ characterization techniques.Firstly,we introduce conventionally proposed traditional catalytic mechanisms and novel evolutionary mechanisms of OER,and highlight the significance of optimal catalytic pathways and intrinsic stability.Next,we provide a comprehensive overview of the fundamental working principles,different detection modes,applicable scenarios,and limitations associated with the in-situ characterization techniques.Further,we exemplified the in-situ studies and discussed phase transition detection,visualization of speciation evolution,electronic structure tracking,observation of reaction active intermediates,and monitoring of catalytic products,as well as establishing catalytic structure-activity relationships and catalytic mechanism.Finally,the key challenges and future perspectives for demystifying the water oxidation process are briefly proposed.
基金financially supported by the National Natural Science Foundation of China(Grant No.22179015,21872142,22302026)the Liao Ning Revitalization Talents Program(XLYC1807196)+1 种基金the fund of the State Key Laboratory of Catalysis in DICP(N-22-06)the open fund of the State Key Laboratory of Molecular Reaction Dynamics in DICP,CAS(SKLMRD-K202414)。
文摘High-entropy(HE)design provides ample opportunities for accessing catalysts with unique physiochemical properties for advanced energy and environmental applications.Although a variety of multi-cationic high-entropy materials(HEMs)have been identified,HEMs consisted of multiple cationic and anionic elements are still limited.Herein,we present the design and synthesis of a series of rutile-structured high-entropy oxy fluorides(HEOFs),including[RuO_(2)]x[MgMnZnCoF_(2)]y,[MnO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[MoO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[SnO_(2)]_(x)[MgMnZnCoF_(2)]_(y)and[TiO_(2)]_(x)[MgMnZnCoF_(2)]_(y)(x:y=3:1,2:1,1:1).All the HEOFs are obtained through mechanochemical alloying rutile-structured oxide and fluoride precursors and the HEOFs inherit the crystal structures of the skeleton oxides.Moreover,the HEOFs exhibit enhanced electrocatalytic oxygen evolution reaction(OER)activity than the corresponding oneelement precursors.Typically,the best-performed HEOF[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)catalyst requires an overpotential of 240 mV to achieve a current density of 10 mA cm^(-2),which is lower than RuO_(2)(291 mV),More impressively,the specific mass activity of[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)is 537.1 A g_(Ru)^(-1)at1.55 V(vs RHE),which is ca.7.6 times that of RuO_(2)(70.5 A g_(Ru)^(-1)).The enhanced electrocata lytic OER performance obtained on[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)is ascribed to the contribution of the different cationic and anionic elements that modulates the electronic structures of the pristine RuO_(2),which facilitates efficient OER kinetics.This work demonstrates the efficacy of high-entropy design towards approaching excellent catalysts for enhanced electrocatalysis.
基金National Natural Science Foundation of China(22478310,U21A20286 and 22206054)。
文摘Transition metal-based nanomaterials have emerged as promising electrocatalysts for oxygen evolution reaction(OER).Considerable research efforts have shown that self-reconstruction occurs on these nanomaterials under operating conditions of OER process.However,most of them undergo incomplete reconstruction with limited thickness of reconstruction layer,leading to low component utilization and arduous exploration of real catalytic mechanism.Herein,we identify the dynamic behaviors in complete reconstruction of Co-based complexes during OER.The hollow phytic acid(PA)cross-linked CoFe-based complex nanoboxes with porous nanowalls are designed because of their good electrolyte penetration and mass transport ability,in favor of the fast and complete reconstruction.A series of experiment characterizations demonstrate that the reconstruction process includes the fast substitution of PA by OH-to form Co(Fe)(OH)xand subsequent potential-driven oxidation to Co(Fe)OOH.The obtained CoFeOOH delivers a low overpotential of 290 mV at a current density of 10 mA cm^(-2)and a long-term stability.The experiment results together with theory calculations reveal that the Fe incorporation can result in the electron rearrangement of reconstructed CoFeOOH and optimization of their electronic structure,accounting for the enhanced OER activity.The work provides new insights into complete reconstruction of metal-based complexes during OER and offers guidelines for rational design of high-performance electrocatalysts.
文摘Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy is reported here,which has been proven to be effective in preparing highly active electrocatalyst.For example,the cobalt,sulfur,and phosphorus modulated nickel hydroxide(denoted as NiCoPSOH)only needs an overpotential of 232 mV to reach a current density of 20 mA cm^(–2),demonstrating excellent OER performances.The cation and anion modulation facilitates the generation of high-valent Ni species,which would activate the lattice oxygen and switch the OER reaction pathway from conventional adsorbate evolution mechanism to lattice oxygen mechanism(LOM),as evidenced by the results of electrochemical measurements,Raman spectroscopy and differential electrochemical mass spectrometry.The LOM pathway of NiCoPSOH is further verified by the theoretical calculations,including the upshift of O 2p band center,the weakened Ni–O bond and the lowest energy barrier of rate-limiting step.Thus,the anion and cation modulated catalyst NiCoPSOH could effectively accelerate the sluggish OER kinetics.Our work provides a new insight into the cation and anion modulation,and broadens the possibility for the rational design of highly active electrocatalysts.
基金financial support from the National Natural Science Foundation of China(21875224 and22179121)Knowledge Innovation Program of Wuhan-Basic Research(2022010801010202)Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202201)。
文摘Developing highly active oxygen evolution reaction(OER)electrocatalysts with robust durability is essential in producing high-purity hydrogen through water electrolysis.Layered double hydroxide(LDH)based catalysts have demonstrated efficient catalytic performance toward the relatively sluggish OER.By considering the promotion effect of phosphate(Pi)on proton transfer,herein,a facile phosphate acid(PA)surface-neutralization strategy is developed to in-situ construct NiCo-LDH/NiCoPi hetero-sheets toward OER catalysis.OER activity of NiCoLDH is significantly boosted due to the proton promotion effect and the electronic modulation effect of NiCoPi.As a result,the facilely prepared NiCo-LDH/NiCoPi catalyst displays superior OER catalytic activity with a low overpotential of 300 mV to deliver 100 mA cm^(-2)OER and a Tafel slope of 73 mV dec^(-1).Furthermore,no visible activity decay is detected after a 200-h continuous OER operation.The present work,therefore,provides a promising strategy to exploit robust OER electrocatalysts for commercial water electrolysers.
基金supported by the financial support of the Guangxi Science and Technology Major Projects(Guike AA23023033)。
文摘Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge.Here,an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide(CoMoO_(4)/Co_(3)O_(4)@CC)in a favorable direction to improve the OER performance.Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching,with the formation of a dynamically stable amorphous-crystalline heterostructure.Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co_(3)O_(4) are crucial in enhancing the catalytic performance.Consequently,the reconstructed CoMoO_(4)/Co_(3)O_(4)@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm^(-2) in 1 M KOH,and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices,achieving ultra-long stability for over 500 and 1200 h,respectively.This work provides a promising route for the construction of high-performance electrocatalysts.
基金National Natural Science Foundation of China (22209094, 22209093)Research Funds of Institute of Zhejiang University-Quzhou (No. IZQ2023RCZX032)+2 种基金USTB Mat Com of Beijing Advanced Innovation Center for Materials Genome EngineeringMinistry of Education, Youth and Sports of the Czech Republic through the e-INFRA CZ (ID:90254)project Quantum materials for applications in sustainable technologies (QM4ST), funded as project No. CZ.02.01.01 /00/22_008/0004572。
文摘Two-dimensional transition metal carbides(MXenes) have been demonstrated to be promising supports for single-atom catalysts(SACs) to enable efficient oxygen evolution reaction(OER).However,the rational design of MXene-based SACs depends on an experimental trial-and-error approach.A theoretical guidance principle is highly expected for the efficient evaluation of MXene-based SACs.Herein,highthroughput screening was performed through first-principles calculations and machine learning techniques.Ti_(3)C_(2)(OH)_(x),V_(3)C_(2)(OH)_(x),Zr_(3)C_(2)(OH)_(x),Nb_(3)C_(2)(OH)_(x),Hf_(3)C_(2)(OH)_(x),Ta_(3)C_(2)(OH)_(x),and W_(3)C_(2)(OH)_(x) were screened out based on their excellent stability.Zn,Pd,Ag,Cd,Au,and Hg were proposed to be promising single atoms anchored in MXenes based on cohesive energy analysis.Hf_(3)C_(2)(OH)_(x) with a Pd single atom delivers a theoretical overpotential of 81 mV.Both moderate electron-deficient state and high covalency of metal-carbon bonds were critical features for the high OER reactivity.This principle is expected to be a promising approach to the rational design of OER catalysts for metal-air batteries,fuel cells,and other OER-based energy storage devices.
基金the funding support from the Research Grants Council of the Hong Kong Special Administrative Region,China[Project No.CityU11308923]the Basic Research Project from Shenzhen Science and Technology Innovation Committee in Shenzhen,China(No.JCYJ20210324134012034)+5 种基金the Applied Research Grant of City University of Hong Kong(project No.of 9667247)Chow Sang Sang Group Research Fund of City University of Hong Kong(project No.9229123)the funding supported by the Seed Collaborative Research Fund Scheme of State Key Laboratory of Marine Pollution which receives regular research funding from Innovation and Technology Commission(ITC)of the Hong Kong SAR Governmentthe JSPS KAKENHI(No.JP23K13703 and JP23KF0102)the high-level science and technology talents project of Lvliang City(No.2022RC07)foundation of Shanxi supercomputing center of China(No.11sxsc202301).
文摘The design of cost-effective electrocatalysts is an open challenging for oxygen evolution reaction(OER)due to the“stable-oractive”dilemma.Zirconium dioxide(ZrO_(2)),a versatile and low-cost material that can be stable under OER operating conditions,exhibits inherently poor OER activity from experimental observations.Herein,we doped a series of metal elements to regulate the ZrO_(2)catalytic activity in OER via spin-polarized density functional theory calculations with van der Waals interactions.Microkinetic modeling as a function of the OER activity descriptor(G_(O*)-G_(HO*))displays that 16 metal dopants enable to enhance OER activities over a thermodynamically stable ZrO_(2)surface,among which Fe and Rh(in the form of single-atom dopant)reach the volcano peak(i.e.the optimal activity of OER under the potential of interest),indicating excellent OER performance.Free energy diagram calculations,density of states,and ab initio molecular dynamics simulations further showed that Fe and Rh are the effective dopants for ZrO_(2),leading to low OER overpotential,high conductivity,and good stability.Considering cost-effectiveness,single-atom Fe doped ZrO_(2)emerged as the most promising catalyst for OER.This finding offers a valuable perspective and reference for experimental researchers to design cost-effective catalysts for the industrial-scale OER production.
基金financially supported by the National Natural Science Foundation of China(52071072)the Fundamental Research Funds for the Central Universities(2023GFZD03)+4 种基金the Natural Science Foundation-Steel,the Iron Foundation of Hebei Province(E2022501030)the Key Research and Development Plan of Qinhuangdao City(202302B013)the Liaoning Applied Basic Research Program(2023JH2/101300011)the Basic scientific research project of Liaoning Province Department of Education(LJKZZ20220024)the Shenyang Science and Technology Project(23-407-3-13)。
文摘The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER is a four-step,four-electron reaction,and its slow kinetics result in high overpotentials,posing a challenge.To address this issue,numerous strategies involving modified catalysts have been proposed and proven to be highly efficient.In these strategies,the introduction of strain has been widely reported because it is generally believed to effectively regulate the electronic structure of metal sites and alter the adsorption energy of catalyst surfaces with reaction intermediates.However,strain has many other effects that are not well known,making it an important yet unexplored area.Based on this,this review provides a detailed introduction to the various roles of strain in OER.To better explain these roles,the review also presents the definition of strain and elucidates the potential mechanisms of strain in OER based on the d-band center theory and adsorption volcano plot.Additionally,the review showcases various ways of introducing strain in OER through examples reported in the latest literature,aiming to provide a comprehensive perspective for the development of strain engineering.Finally,the review analyzes the appropriate proportion of strain introduction,compares compressive and tensile strain,and examines the impact of strain on stability.And the review offers prospects for future research directions in this emerging field.
基金We acknowledge the National Natural Science Foundation of China(No.22275134)for fi nancial support.
文摘N-doped carbon materials,with their applications as electrocatalysts for the oxygen reduction reaction(ORR),have been extensively studied.However,a negletcted fact is that the operating potential of the ORR is higher than the theoretical oxida-tion potential of carbon,possibly leading to the oxidation of carbon materials.Consequently,the infl uence of the structural oxidation evolution on ORR performance and the real active sites are not clear.In this study,we discover a two-step oxida-tion process of N-doped carbon during the ORR.The fi rst oxidation process is caused by the applied potential and bubbling oxygen during the ORR,leading to the oxidative dissolution of N and the formation of abundant oxygen-containing functional groups.This oxidation process also converts the reaction path from the four-electron(4e)ORR to the two-electron(2e)ORR.Subsequently,the enhanced 2e ORR generates oxidative H_(2)O_(2),which initiates the second stage of oxidation to some newly formed oxygen-containing functional groups,such as quinones to dicarboxyls,further diversifying the oxygen-containing functional groups and making carboxyl groups as the dominant species.We also reveal the synergistic eff ect of multiple oxygen-containing functional groups by providing additional opportunities to access active sites with optimized adsorption of OOH*,thus leading to high effi ciency and durability in electrocatalytic H_(2)O_(2) production.
基金This work is supported by the National Key Research and Development Program(No.2018YFA0208600)the National Natural Science Foundation of Chi-na(No.U19A2015,No.22102167)+2 种基金CAS Project for Young Scientists in Basic Research(YSBR-051)Wenhua Zhang is supported by USTC Tang Scholarship and State Scholarship Fund(202206345005)The calculations were performed at the Super-computing Center of University of Science and Technology of China(USTCSCC).
文摘The dynamic adsorption of possible intermediates on single-atom catalysts(SACs)under working condition plays a key role in the electrocatalytic performance by the oxygen evolution reaction(OER),and therefore the performance of the dynamic adsorption should be fully considered in the theoretical screening of potential SACs.Based on density functional theory calculations,the OER performance of 27 types of C_(2)N-supported single transition metal atoms(TM@C_(2)N)is systematically investigated without and with considering the dynamic adsorption of possible intermediates.Without considering dynamic adsorption,only Rh@C_(2)N and Ni@C_(2)N are screened out as good catalysts.However,by further considering the dynamic adsorption configurations of possible intermediates,more promising TM@C_(2)N SACs including Fe(Co,Ni,Ru,Rh,Ir)@C_(2)N toward the OER are screened out.The presence of the intermediates(*HO,*O)on SACs could shift their d band center toward lower energy level,which makes the interaction between the adsorbate and SACs moderate and thus enhances their OER performance.The present work is instructive for further screening and designing of efficient single-atom catalysts for the oxygen evolution reaction.
基金Funded by the Doctoral Fund of Chengdu University(No.2081919131)the Sichuan Science and Technology Program(No.2023YFG0229)。
文摘Ni^(2+)/Cu^(2+)/SO_(4)^(2-)/polyvinyl alcohol precursor fibers with uniform diameters were prepared through electrospinning.Nickel-based composite nanoalloys containing Ni,Cu,and S were prepared through heat treatment in an Ar atmosphere.The experimental results show that the main components of the prepared nanoalloys are NiCu,Ni_(3)S_(2),Ni,and C.The nanoalloys exhibit fine grain sizes about 200-500 nm,which can increase with increasing heat treatment temperature.Electrochemical test results show that the nickel sulfidemodified NiCu nanoalloy composites exhibit excellent oxygen evolution reaction properties,and the oxygen evolution reaction properties gradually improve with the increasing heat treatment temperature.The sample prepared at 1 000℃ for 40 min show a low overpotential of 423 mV and a small Tafel slope of 134 mV·dec^(-1) at a current density of 10 mA·cm^(-2).
基金National Natural Science Foundation of China,Grant/Award Number:22172063Young Taishan Scholars Program,Grant/Award Number:tsqn201812080+1 种基金China Scholarship Council(CSC),Grant/Award Number:202008130132Independent Cultivation Program of Innovation Team of Ji'nan City,Grant/Award Number:2021GXRC052。
文摘Electrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon emission.However,the sluggish kinetics of oxygen evolution reaction on the anode side of the watersplitting device significantly hinders its practical applications.Generally,the efficiency of oxygen evolution processes depends greatly on the availability of cost‐effective catalysts with high activity and selectivity.In recent years,extensive theoretical and experimental studies have demonstrated that cobalt(Co)‐based nanomaterials,especially low‐dimensional Co‐based nanomaterials with a huge specific surface area and abundant unsaturated active sites,have emerged as versatile electrocatalysts for oxygen evolution reactions,and thus,great progress has been made in the rational design and synthesis of Co‐based nanomaterials for electrocatalytic oxygen evolution reactions.Considering the remarkable progress in this area,in this timely review,we highlight the most recent developments in Co‐based nanomaterials relating to their dimensional control,defect regulation(conductivity),electronic structure regulation,and so forth.Furthermore,a brief conclusion about recent progress achieved in oxygen evolution on Co‐based nanomaterials,as well as an outlook on future research challenges,is given.
