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
Pt-based nanocatalysts offer excellent prospects for various industries.However,the low loading of Pt with excellent performance for efficient and stable nanocatalysts still presents a considerable challenge.In this s...Pt-based nanocatalysts offer excellent prospects for various industries.However,the low loading of Pt with excellent performance for efficient and stable nanocatalysts still presents a considerable challenge.In this study,nanocatalysts with ultralow Pt content,excellent performance,and carbon black as support were prepared through in-situ synthesis.These~2-nm particles uniformly and stably dispersed on carbon black because of the strong s-p-d orbital hybridizations between carbon black and Pt,which suppressed the agglomeration of Pt ions.This unique structure is beneficial for the hydrogen evolution reaction.The catalysts exhibited remarkable catalytic activity for hydrogen evolution reaction,exhibiting a potential of 100 mV at 100 mA·cm^(-2),which is comparable to those of commercial Pt/C catalysts.Mass activity(1.61 A/mg)was four times that of a commercial Pt/C catalyst(0.37 A/mg).The ultralow Pt loading(6.84wt%)paves the way for the development of next-generation electrocatalysts.展开更多
The utilization of nickel-based catalysts as alternatives to expensive platinum-based(Pt-based)materials for the hydrogen evolution reaction in acidic electrolytes has attracted considerable attention due to their pot...The utilization of nickel-based catalysts as alternatives to expensive platinum-based(Pt-based)materials for the hydrogen evolution reaction in acidic electrolytes has attracted considerable attention due to their potential for enabling cost-effective industrial applications.However,the unsatisfied cyclic stability and electrochemical activity limit their further application.In this work,nickel-molybdenum(Ni-Mo)alloy catalysts were successfully synthesized through a comprehensive process including electrodeposition,thermal annealing,and electrochemical activation.Owing to the synergistic interaction of molybdenum trinickelide(Ni_(3)Mo)and molybdenum dioxide(MoO_(2))in Ni-Mo alloy,the catalyst display superior overall electrochemical properties.A low overpotential of 86 mV at 10 mA/cm^(2)and a Tafel slope of 74.0 mV/dec in 0.5 mol/L H_(2)SO_(4)solution can be achieved.Notably,remarkable stability with negligible performance degradation even after 100 h could be maintained.This work presents a novel and effective strategy for the design and fabrication of high-performance,non-precious metal electrocatalysts for acidic water electrolysis.展开更多
Pt-based materials are the benchmarked catalysts in the cathodic hydrogen evolution reaction(HER)of water splitting;the prohibitive cost and scarcity of Pt immensely impede the commercialization of hydrogen energy.Ru ...Pt-based materials are the benchmarked catalysts in the cathodic hydrogen evolution reaction(HER)of water splitting;the prohibitive cost and scarcity of Pt immensely impede the commercialization of hydrogen energy.Ru has aroused significant concern because of its Pt-like activity and much lower price.However,it’s still a top priority to minimize the Ru loading and pursue the most superior cost performance.展开更多
Constructing clus ter heterostructures with strongly coupled interfaces is of great importance to accelerating the catalytic reactions that involve multiple intermediates.Herein,a strongly coupled cluster heterostruct...Constructing clus ter heterostructures with strongly coupled interfaces is of great importance to accelerating the catalytic reactions that involve multiple intermediates.Herein,a strongly coupled cluster heterostructure composed of platinum and molybdenum carbide(Pt@Mo_(2)C)derived from polyoxometalate clusters is designed to achieve excellent alkaline hydrogen evolution reaction.The Pt@Mo_(2)C cluster exhibits strong electronic interactions between Pt and Mo_(2)C,working together to facilitate the H_(2)O dissociation by concurrently binding intermediates(Pt-H*and Mo-OH*),thus accelerating the kinetics of the rate-determining Volmer step.Theoptimized Pt@Mo_(2)C exhibits a high mass activity of12.1 A·mgpt^(-1),19.2 times higher than that of 20%Pt/C in alkaline media.Moreover,it can be stabilized at a current density of 100 mA·cm^(-2)for more than 200 h.This work demonstrated the superiority of the cluster heterostructures and co-catalytic effect towards the development of highly efficient electrocatalysts.展开更多
Employing multiple metals for synergistic electronic structure regulation emerges as a promising approach to develop highly efficient and robust electrocatalysts for hydrogen evolution at ampere levels.In this study,a...Employing multiple metals for synergistic electronic structure regulation emerges as a promising approach to develop highly efficient and robust electrocatalysts for hydrogen evolution at ampere levels.In this study,a series of Schreibersite-type intermetallic compounds,particularly Mo_(2)Fe_(0.8)Ru_(0.2)P,are synthesized through high-temperature solid-phase synthesis.Experimental results demonstrate that the integration of Ru significantly improves the kinetics of proton adsorption and desorption during the hydrogen evolution reaction(HER).Additionally,density functional theory(DFT)calculations and X-ray absorption near edge structure(XANES)analyses effectively corroborate the pronounced d-orbital hybridization of Fe within the structure,which facilitates the transfer of hydroxide ions and the maintenance of material durability during alkaline HER processes.Remarkably,Mo_(2)Fe_(0.8)Ru_(0.2)P exhibits superior alkaline HER activity,characterized by an overpotential of merely 48 mV at a current density of 10 mA cm^(-2).After prolonged operation of 1000 h at high current densities(1.1 A cm^(-2)),the activity decline remains minimal,under 4%(with overpotential increasing from 258 mV to 268 mV).These results demonstrate the potential of strategically combining metallic elements to design high-performance industrial-grade electrocatalysts.展开更多
Exploring platinum single-atom electrocatalysts(SACs)is of great significance for effectively catalyzing the hydrogen evolution reaction in order to maximize the utilization of metal atoms.Herein,ruthenium clusters wi...Exploring platinum single-atom electrocatalysts(SACs)is of great significance for effectively catalyzing the hydrogen evolution reaction in order to maximize the utilization of metal atoms.Herein,ruthenium clusters with several atoms(Rux)supported on nitrogen-doped,cost-efficient Black Pearls 2000(Ru_(x)NBP),were synthesized as initial materials via a simple hydrothermal method.Then,[PtCl_(4)]^(2–)ion was reductively deposited on RuxNBP to obtain a Pt SAC(Pt1/RuxNBP).Electrochemical measurements demonstrate the excellent HER performance of Pt_(1)/Ru_(x)NBP with a 5.7-fold increase in mass activity compared to the commercial Pt/C at 20 mV.Moreover,the cell voltage of the proton exchange membrane electrolyzer with Pt_(1)/Ru_(x)NBP is 20 mV lower compared to that with commercial Pt/C at 1.0 A cm^(−2).Physical characterization and density functional theory calculations revealed that the preserved Pt–Cl bond of[PtCl_(4)]^(2–)and the RuxNBP support co-regulate the 5d state of isolated Pt atoms and enhance the catalytic HER capacity of Pt1/RuxNBP.展开更多
As a clean energy source,hydrogen plays a critical role in the global mission to achieve carbon neutrality.Among varied hydrogen production techniques,water electrolysis driven by clean energy,such as solar or wind en...As a clean energy source,hydrogen plays a critical role in the global mission to achieve carbon neutrality.Among varied hydrogen production techniques,water electrolysis driven by clean energy,such as solar or wind energy,is the most promising and viable option,with the advantages of celerity,high efficiency,cleanliness,and sustainability.However,this process necessitates a highly active and durable hydrogen evolution reaction(HER)catalyst to enhance the overall reaction efficiency.This article thoroughly reviews the recent development of electrocatalysts exhibiting high-performance HER.In particular,a comprehensive look at noble metals platinum(Pt),ruthenium(Ru),iridium(Ir),and non-noble metals,including sulfides,carbides,nitrides and phosphides is taken.Synthesis strategies,methods for enhancing performance,and the correlation between structure,composition,and catalytic performance are discussed.We also pay particular attention to density functional theory(DFT)calculations to reveal the mechanisms behind the improvement of HER performance.Finally,the critical challenges associated with electrochemical water splitting and propose coping strategies are presented.展开更多
Transition metal carbides,known as MXenes,particularly Ti_(3)C_(2)T_(x),have been extensively explored as promising materials for electrochemical reactions.However,transition metal carbonitride MXenes with high nitrog...Transition metal carbides,known as MXenes,particularly Ti_(3)C_(2)T_(x),have been extensively explored as promising materials for electrochemical reactions.However,transition metal carbonitride MXenes with high nitrogen content for electrochemical reactions are rarely reported.In this work,transition metal carbonitride MXenes incorporated with Pt-based electrocatalysts,ranging from single atoms to sub-nanometer dimensions,are explored for hydrogen evolution reaction(HER).The fabricated Pt clusters/MXene catalyst exhibits superior HER performance compared to the single-atom-incorporated MXene and commercial Pt/C catalyst in both acidic and alkaline electrolytes.The optimized sample shows low overpotentials of 28,65,and 154 mV at a current densities of 10,100,and 500 m A cm^(-2),a small Tafel slope of 29 m V dec^(-1),a high mass activity of 1203 mA mgPt^(-1)and an excellent turnover frequency of 6.1 s^(-1)in the acidic electrolyte.Density functional theory calculations indicate that this high performance can be attributed to the enhanced active sites,increased surface functional groups,faster charge transfer dynamics,and stronger electronic interaction between Pt and MXene,resulting in optimized hydrogen absorption/desorption toward better HER.This work demonstrates that MXenes with a high content of nitrogen may be promising candidates for various catalytic reactions by incorporating single atoms or clusters.展开更多
High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of subs...High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of substrate and active metal particles,enabling excellent catalytic properties and stability.Herein,the optimization strategy of delignification and 2,2,6,6-tetramethylpyperidine-1-oxyl(TEMPO)oxidization was developed to modify the porous structure and active groups of wood substrate,and Ru doped Co/CO_(2)P(Ru-Co/CO_(2)P)nanoparticles were encapsulated into the optimized wood carbon substrate(Ru-Co/CO_(2)P@TDCW)for the efficient pH-universal hydrogen evolution reaction(HER).The nanopore and carboxyl groups were produced by delignification and TEMPO oxidation,which accelerated the dispersion and deposition of Ru-Co/CO_(2)P nanoparticles.The RuCo alloy and RuCoP nanoparticles were produced with the doping of Ru,and more Ru-Co/CO_(2)P nanoparticles were anchored by the delignified and TEMPO oxidized wood carbon(TDCW).As anticipated,the Ru-Co/CO_(2)P@TDCW catalyst exhibited excellent pH-universal HER activity,and only 16.6,93,and 43 mV of overpotentials were required to deliver the current density of 50 mA cm^(-2)in alkaline,neutral,and acidic electrolytes,outperforming the noble Pt/C/TDCW catalyst significantly.In addition,Ru-Co/CO_(2)P@TDCW catalyst presented excellent stability for more than 600 h working at 100 mA cm^(-2)in alkaline solution(1.0 M KOH).Density function theory(DFT)results revealed that energy barriers for the dissociation of H_(2)O and the formation of H_(2)were decreased by the doping of Ru,and the conductivity and efficiency of electron migration were also enhanced.This work demonstrated a strategy to optimize the structure and properties of wood carbon substrate,providing a promising strategy to synthesize high-efficiency catalyst for H_(2)production.展开更多
A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se dopin...A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se doping level,a hollow spherical catalyst structure composed of CoSSe was successfully synthesized,which exhibited exceptional activity for hydrogen evolution in acidic solutions.The influences of Se doping on the microstructure and catalytic mechanism of hydrogen evolution reaction(HER)of these composites were systematically investigated.The experimental results reveal that the hollow spherical sample displays an overpotential value of 143 mV along with a Tafel slope value of 69.8 mV·dec^(-1)at a current density of 10 mA·cm^(-2)in an acid aqueous solution.Furthermore,it demonstrates remarkable cycling stability after undergoing 3000 cycles.The comprehensive analysis indicates that Se doping optimizes the electronic structure and enhances conductivity,meanwhile the unique hollow spherical architecture increases active sites for HER and significantly improves overall electrocatalytic performance.展开更多
An in-depth understanding of the catalyst surface evolution is crucial for precise control of active sites,yet this aspect has often been overlooked.This study reveals the spontaneous anion regulation mechanism of Br-...An in-depth understanding of the catalyst surface evolution is crucial for precise control of active sites,yet this aspect has often been overlooked.This study reveals the spontaneous anion regulation mechanism of Br-doped CoP electrocatalysts in the alkaline hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The introduction of Br modulates the electronic structure of the Co site,endowing Br-CoP with a more metallic character.In addition,P ion leaching promotes the in situ reconstruction of Br-CoOOH,which is the real active site for the OER reaction.Meanwhile,the HER situation is different.On the basis of P ion leaching,the leaching of Br ions promotes the formation of CoP-Co(OH)_(2) active species.In addition,Br doping enhances the adsorption of^(*)H,showing excellent H adsorption free energy,thereby greatly improving the HER activity.Simultaneously,it also enhances the adsorption of OOH^(*),effectively facilitating the occurrence of OER reactions.Br-CoP only needs 261 and 76 mV overpotential to drive the current density of 20 mA cm^(-2) and 10 mA^(-2),which can be maintained unchanged for 100 h.This study provides new insights into anion doping strategies and catalyst reconstruction mechanisms.展开更多
The fabrication of efficient and stable catalysts to accelerate the kinetics of the hydrogen evolution reaction(HER)is a crucial step in the development of sustainable energy production.The structural design of Pt-bas...The fabrication of efficient and stable catalysts to accelerate the kinetics of the hydrogen evolution reaction(HER)is a crucial step in the development of sustainable energy production.The structural design of Pt-based catalysts with efficient atom utilization remains a pivotal factor in the continued advancement of HER catalysts.In this work,we synthesized phosphorylated Mo-based particles embedded in P-doped carbon materials for the optimized loading of platinum nanoparticles(Pt/Mo-P@C).Theoretical results indicate that the catalytic efficacy of the materials can be enhanced by altering the electronic structure of Pt nanoparticles through the precise formation of Pt-Mo bond and multiple heterostructures.The catalysts exhibited exceptional mass activity after low-temperature reduction,achieving a current density of 100 mA·cm−2 at 54.4 mV,which is lower than that of the commercial Pt/C catalyst.Furthermore,the mass activity of the main catalyst was 6.7 times greater than that of the commercial Pt/C catalyst at an overpotential of 50 mV.展开更多
CoFe bimetallic hydroxides(CoFe BMHs)find wide applications as excellent catalysts in the field of water splitting.However,no study has systematically investigated the influence of the morphologies of CoFe BMHs on cat...CoFe bimetallic hydroxides(CoFe BMHs)find wide applications as excellent catalysts in the field of water splitting.However,no study has systematically investigated the influence of the morphologies of CoFe BMHs on catalyst performance.In this study,CoFe BMH nanoflowers(CoFe BMH NFs),CoFe BMH nanosheets(CoFe BMH NSHs),CoFe BMH nanorods(CoFe BMH NRs),and CoFe BMH nanospheres(CoFe BMH NSPs)were prepared on nickel foam via a hydrothermal method.CoFe BMH NSHs exhibited the most beneficial catalytic activity.At a current density of 100 mA·cm^(-2),its overpotential for oxygen evolution reaction(OER)was 282 mV,and the overall water splitting voltage was 2.05 V.The double-layer charging capacitance(Cdl)value of CoFe BMH NSHs was the largest in CoFe BMHs,which proves that CoFe BMH NSHs have the largest active area.Furthermore,the active site in the OER process was metal oxyhydroxide(MOOH)through in situ Raman characterization,and the generation of the active substance was an irreversible process.This work provides important insights into the design of catalyst morphologies and offers valuable guidelines for the enhancement of the performance of other catalysts.展开更多
Single-atom catalysts(SACs)have garnered interest in designing their ligand environments,facilitating the modification of single catalytic sites toward high activity and selectivity.Despite various synthetic approache...Single-atom catalysts(SACs)have garnered interest in designing their ligand environments,facilitating the modification of single catalytic sites toward high activity and selectivity.Despite various synthetic approaches,it remains challenging to achieve a catalytically favorable coordination structure simultaneously with the feasible formation of SACs at low temperatures.Here,a new type of coordination structure for Pt SACs is introduced to offer a highly efficient hydrogen evolution reaction(HER)catalyst,where Pt SACs are readily fabricated by atomically confining PtCl_(2)on chemically driven NO_(2)sites in two-dimensional nitrogen-doped carbon nanosheets at room temperature.The resultant Pt SACs form the NO_(2)-Pt-Cl_(2)coordination structure with an atomic dispersion,as revealed by X-ray spectroscopy and transmission electron microscopy investigations.Moreover,our first-principles density functional theory(DFT)calculations show strong interactions in the coordination by computing the binding energy and charge density difference between PtCl_(2)and NO_(2).Pt SACs,established on the NO_(2)-functionalized carbon support,demonstrate the onset potential of 25 mV,Tafel slope of 40 mV dec^(-1),and high specific activity of 1.35 A mgPt^(-1).Importantly,the Pt SACs also exhibit long-term stability up to 110 h,which is a significant advance in the field of single-atom Pt catalysts.The newly developed coordination structure of Pt SACs features a single Pt active center,providing hydrogen binding ability comparable to that of Pt(111),enhanced long-term durability due to strong metal-support interactions,and the advantage of room-temperature fabrication.展开更多
Designing highly active electrocatalysts for the hydrogen evolution reaction(HER)and oxygen evolution and reduction reactions(OER and ORR)is pivotal to renewable energy technology.Herein,based on density functional th...Designing highly active electrocatalysts for the hydrogen evolution reaction(HER)and oxygen evolution and reduction reactions(OER and ORR)is pivotal to renewable energy technology.Herein,based on density functional theory(DFT)calculations,we systematically investigate the catalytic activity of iron-nitrogen-carbon based covalent organic frameworks(COF)monolayers with axially coordinated ligands(denotes as Fe N_(4)-X@COF,X refers to axial ligand,X=-SCN,-I,-H,-SH,-NO_(2),-Br,-ClO,-Cl,-HCO_(3),-NO,-ClO_(2),-OH,-CN and-F).The calculated results demonstrate that all the catalysts possess good thermodynamic and electrochemical stabilities.The different ligands axially ligated to the Fe active center could induce changes in the charge of the Fe center,which further regulates the interaction strength between intermediates and catalysts that governs the catalytic activity.Importantly,FeN_(4)-SH@COF and Fe N_(4)-OH@COF are efficient bifunctional catalysts for HER and OER,FeN_(4)-OH@COF and FeN_(4)-I@COF are promising bifunctional catalysts for OER and ORR.These findings not only reveal promising bifunctional HER/OER and OER/ORR catalysts but also provide theoretical guidance for designing optimum ironnitrogen-carbon based catalysts.展开更多
Hydrogen evolution reaction(HER)in acidic media has been spotlighted for hydrogen production since it is a favourable kinetics with the supplied protons from a counterpart compared to that within alkaline environment....Hydrogen evolution reaction(HER)in acidic media has been spotlighted for hydrogen production since it is a favourable kinetics with the supplied protons from a counterpart compared to that within alkaline environment.However,there is no choice but to use a platinum-based catalyst yet.As for a noble metal-free electrocatalyst,incorporation of earth-abundant transition metal(TM)atoms into nanocarbon platforms has been extensively adopted.Although a data-driven methodology facilitates the rational design of TM-anchored carbon catalysts,its practical application suffers from either a simplified theoretical model or the prohibitive cost and complexity of experimental data generation.Herein,an effective and facile catalyst design strategy is proposed based on machine learning(ML)and its model verification using electrochemical methods accompanied by density functional theory simulations.Based on a Bayesian genetic algorithm ML model,the Ni-incorporated carbon quantum dots(Ni@CQD)loaded on a three-dimensional reduced graphene oxide conductor are proposed as the best HER catalyst amongst the various TM-incorporated CQDs under the optimal conditions of catalyst loading,electrode type,and temperature and pH of electrolyte.The ML results are validated with electrochemical experiments,where the Ni@CQD catalyst exhibited superior HER activity,requiring an overpotential of 151 mV to achieve 10 mAcm^(−2) with a Tafel slope of 52 mV dec^(−1) and impressive durability in acidic media up to 100 h.This methodology can provide an effective route for the rational design of highly active electrocatalysts for commercial applications.展开更多
Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolu...Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.展开更多
The development of highly active and cost-effective catalysts for the full pH range of the hydrogen evolution reaction(HER)to meet the industrial application demands is an urgent challenge.In this work,the performance...The development of highly active and cost-effective catalysts for the full pH range of the hydrogen evolution reaction(HER)to meet the industrial application demands is an urgent challenge.In this work,the performance and structure–activityrelationships of CuIr alloys prepared by the pulsed laser ablation in liquid technique as full pH range HER catalysts wereinvestigated.Results indicated that Ir is doped into the Cu matrix as single atoms in CuIr-0.1,and CuIr-0.1 single-atom alloys(SAAs)exhibit superior HER performance and stability across the full pH range,with overpotentials of 135,203,and 172 mVat the current density of 10 mA/cm^(2)in acidic,neutral,and alkaline electrolytes,respectively.The enhanced performance ofCuIr-0.1 SAAs can be attributed to the abundant active sites and accelerated reaction kinetics brought about by the electroniceffects.This work successfully alloyed two immiscible metals to improve the catalytic performance,providing an avenue forthe development of highly efficient and versatile HER catalysts for industrial applications.展开更多
Hydrogen evolution reaction(HER)is unavoidable in many electrochemical synthesis systems,such as CO_(2)reduction,N2reduction,and H_(2)O_(2)synthesis.It makes those electrochemical reactions with multiple electron-prot...Hydrogen evolution reaction(HER)is unavoidable in many electrochemical synthesis systems,such as CO_(2)reduction,N2reduction,and H_(2)O_(2)synthesis.It makes those electrochemical reactions with multiple electron-proton transfers more complex when determining kinetics and mass transfer information.Understanding how HER competes with other electrochemical reduction reactions is crucial for both fundamental studies and system performance improvements.In this study,we employed the oxygen reduction reaction(ORR)as a model reaction to investigate HER competition on a polycrystalline-Au surface,using a rotating ring and disk electrode.It’s proved that water molecules serve as the proton source for ORR in alkaline,neutral,and even acidic electrolytes,and a 4-electron process can be achieved when the overpotential is sufficiently high.The competition from H⁺reduction becomes noticeable at the H⁺concentration higher than 2 mmol L^(–1)and intensi-fies as the H^(+)concentration increases.Based on the electrochemical results,we obtained an equivalent circuit diagram for the ORR system with competition from the H+reduction reaction,showing that these reactions occur in parallel and compete with each other.Electrochemical impedance spectroscopy measurements further confirm this argument.Additionally,we discover that the contribution of H+mass transfer to the total H^(+)reduction current is significant and comparable to the kinetic current.We believe this work will deepen our understanding of HER and its competition in electrochemical reduction systems.展开更多
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 National Natural Science Foundation of China(No.5217042069)the Young Elite Scientist Sponsorship Program by China Association for Science and Technology(CAST)(No.YESS20200103)the Fundamental Research Funds for the Central Universities(No.265QZ2022004)。
文摘Pt-based nanocatalysts offer excellent prospects for various industries.However,the low loading of Pt with excellent performance for efficient and stable nanocatalysts still presents a considerable challenge.In this study,nanocatalysts with ultralow Pt content,excellent performance,and carbon black as support were prepared through in-situ synthesis.These~2-nm particles uniformly and stably dispersed on carbon black because of the strong s-p-d orbital hybridizations between carbon black and Pt,which suppressed the agglomeration of Pt ions.This unique structure is beneficial for the hydrogen evolution reaction.The catalysts exhibited remarkable catalytic activity for hydrogen evolution reaction,exhibiting a potential of 100 mV at 100 mA·cm^(-2),which is comparable to those of commercial Pt/C catalysts.Mass activity(1.61 A/mg)was four times that of a commercial Pt/C catalyst(0.37 A/mg).The ultralow Pt loading(6.84wt%)paves the way for the development of next-generation electrocatalysts.
基金supported by the National Natural Science Foundation of China(22179138).
文摘The utilization of nickel-based catalysts as alternatives to expensive platinum-based(Pt-based)materials for the hydrogen evolution reaction in acidic electrolytes has attracted considerable attention due to their potential for enabling cost-effective industrial applications.However,the unsatisfied cyclic stability and electrochemical activity limit their further application.In this work,nickel-molybdenum(Ni-Mo)alloy catalysts were successfully synthesized through a comprehensive process including electrodeposition,thermal annealing,and electrochemical activation.Owing to the synergistic interaction of molybdenum trinickelide(Ni_(3)Mo)and molybdenum dioxide(MoO_(2))in Ni-Mo alloy,the catalyst display superior overall electrochemical properties.A low overpotential of 86 mV at 10 mA/cm^(2)and a Tafel slope of 74.0 mV/dec in 0.5 mol/L H_(2)SO_(4)solution can be achieved.Notably,remarkable stability with negligible performance degradation even after 100 h could be maintained.This work presents a novel and effective strategy for the design and fabrication of high-performance,non-precious metal electrocatalysts for acidic water electrolysis.
基金supported by the Development Project of Youth Innovation Team in Shandong Colleges and Universities(No.2019KJC031)the Natural Science Foundation of Shandong Province(Nos.ZR2019MB064,ZR2021MB122 and ZR2022MB137)the Doctoral Program of Liaocheng University(No.318051608).
文摘Pt-based materials are the benchmarked catalysts in the cathodic hydrogen evolution reaction(HER)of water splitting;the prohibitive cost and scarcity of Pt immensely impede the commercialization of hydrogen energy.Ru has aroused significant concern because of its Pt-like activity and much lower price.However,it’s still a top priority to minimize the Ru loading and pursue the most superior cost performance.
基金supported by the National Natural Science Foundation of China(Nos.22171287 and 52303274)Taishan Scholar Project of Shandong Province(No.tsqn202103046)+2 种基金Natural Science Foundation of Shandong Province(No.ZR2022QE175)Young Innovative Science and Technology Support Program for Universities of Shandong Province,P.R.China(Nos.2023KJ280 and 2021KJ014)Fundamental Research Funds for the Central Universities(Nos.24CX07007A and 22CX01002A-1)
文摘Constructing clus ter heterostructures with strongly coupled interfaces is of great importance to accelerating the catalytic reactions that involve multiple intermediates.Herein,a strongly coupled cluster heterostructure composed of platinum and molybdenum carbide(Pt@Mo_(2)C)derived from polyoxometalate clusters is designed to achieve excellent alkaline hydrogen evolution reaction.The Pt@Mo_(2)C cluster exhibits strong electronic interactions between Pt and Mo_(2)C,working together to facilitate the H_(2)O dissociation by concurrently binding intermediates(Pt-H*and Mo-OH*),thus accelerating the kinetics of the rate-determining Volmer step.Theoptimized Pt@Mo_(2)C exhibits a high mass activity of12.1 A·mgpt^(-1),19.2 times higher than that of 20%Pt/C in alkaline media.Moreover,it can be stabilized at a current density of 100 mA·cm^(-2)for more than 200 h.This work demonstrated the superiority of the cluster heterostructures and co-catalytic effect towards the development of highly efficient electrocatalysts.
基金supported by Research Grants of the NRF(2023R1A2C2003823,RS-2024-00405818)funded by the National Research Foundation under the Ministry of Science,ICT&Future,Korea。
文摘Employing multiple metals for synergistic electronic structure regulation emerges as a promising approach to develop highly efficient and robust electrocatalysts for hydrogen evolution at ampere levels.In this study,a series of Schreibersite-type intermetallic compounds,particularly Mo_(2)Fe_(0.8)Ru_(0.2)P,are synthesized through high-temperature solid-phase synthesis.Experimental results demonstrate that the integration of Ru significantly improves the kinetics of proton adsorption and desorption during the hydrogen evolution reaction(HER).Additionally,density functional theory(DFT)calculations and X-ray absorption near edge structure(XANES)analyses effectively corroborate the pronounced d-orbital hybridization of Fe within the structure,which facilitates the transfer of hydroxide ions and the maintenance of material durability during alkaline HER processes.Remarkably,Mo_(2)Fe_(0.8)Ru_(0.2)P exhibits superior alkaline HER activity,characterized by an overpotential of merely 48 mV at a current density of 10 mA cm^(-2).After prolonged operation of 1000 h at high current densities(1.1 A cm^(-2)),the activity decline remains minimal,under 4%(with overpotential increasing from 258 mV to 268 mV).These results demonstrate the potential of strategically combining metallic elements to design high-performance industrial-grade electrocatalysts.
文摘Exploring platinum single-atom electrocatalysts(SACs)is of great significance for effectively catalyzing the hydrogen evolution reaction in order to maximize the utilization of metal atoms.Herein,ruthenium clusters with several atoms(Rux)supported on nitrogen-doped,cost-efficient Black Pearls 2000(Ru_(x)NBP),were synthesized as initial materials via a simple hydrothermal method.Then,[PtCl_(4)]^(2–)ion was reductively deposited on RuxNBP to obtain a Pt SAC(Pt1/RuxNBP).Electrochemical measurements demonstrate the excellent HER performance of Pt_(1)/Ru_(x)NBP with a 5.7-fold increase in mass activity compared to the commercial Pt/C at 20 mV.Moreover,the cell voltage of the proton exchange membrane electrolyzer with Pt_(1)/Ru_(x)NBP is 20 mV lower compared to that with commercial Pt/C at 1.0 A cm^(−2).Physical characterization and density functional theory calculations revealed that the preserved Pt–Cl bond of[PtCl_(4)]^(2–)and the RuxNBP support co-regulate the 5d state of isolated Pt atoms and enhance the catalytic HER capacity of Pt1/RuxNBP.
基金supported by the National Natural Science Foundation of China(No.52102470)。
文摘As a clean energy source,hydrogen plays a critical role in the global mission to achieve carbon neutrality.Among varied hydrogen production techniques,water electrolysis driven by clean energy,such as solar or wind energy,is the most promising and viable option,with the advantages of celerity,high efficiency,cleanliness,and sustainability.However,this process necessitates a highly active and durable hydrogen evolution reaction(HER)catalyst to enhance the overall reaction efficiency.This article thoroughly reviews the recent development of electrocatalysts exhibiting high-performance HER.In particular,a comprehensive look at noble metals platinum(Pt),ruthenium(Ru),iridium(Ir),and non-noble metals,including sulfides,carbides,nitrides and phosphides is taken.Synthesis strategies,methods for enhancing performance,and the correlation between structure,composition,and catalytic performance are discussed.We also pay particular attention to density functional theory(DFT)calculations to reveal the mechanisms behind the improvement of HER performance.Finally,the critical challenges associated with electrochemical water splitting and propose coping strategies are presented.
基金the final support of ARC DP220103045the startup support of KFUPMPrince Sultan University for their support。
文摘Transition metal carbides,known as MXenes,particularly Ti_(3)C_(2)T_(x),have been extensively explored as promising materials for electrochemical reactions.However,transition metal carbonitride MXenes with high nitrogen content for electrochemical reactions are rarely reported.In this work,transition metal carbonitride MXenes incorporated with Pt-based electrocatalysts,ranging from single atoms to sub-nanometer dimensions,are explored for hydrogen evolution reaction(HER).The fabricated Pt clusters/MXene catalyst exhibits superior HER performance compared to the single-atom-incorporated MXene and commercial Pt/C catalyst in both acidic and alkaline electrolytes.The optimized sample shows low overpotentials of 28,65,and 154 mV at a current densities of 10,100,and 500 m A cm^(-2),a small Tafel slope of 29 m V dec^(-1),a high mass activity of 1203 mA mgPt^(-1)and an excellent turnover frequency of 6.1 s^(-1)in the acidic electrolyte.Density functional theory calculations indicate that this high performance can be attributed to the enhanced active sites,increased surface functional groups,faster charge transfer dynamics,and stronger electronic interaction between Pt and MXene,resulting in optimized hydrogen absorption/desorption toward better HER.This work demonstrates that MXenes with a high content of nitrogen may be promising candidates for various catalytic reactions by incorporating single atoms or clusters.
基金financially supported by the National Natural Science Foundation of China(32101452)the Research Foundation of Education Bureau of Hunan Province(22B0283)+2 种基金the Hunan Provincial Natural Science Foundation(2022JJ40865)the Talents Research Funding of Central South University of Forestry and Technology(2021YJ007)the Scientific Innovation Fund for Graduate of Central South University of Forestry and Technology(2024CX02005)。
文摘High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of substrate and active metal particles,enabling excellent catalytic properties and stability.Herein,the optimization strategy of delignification and 2,2,6,6-tetramethylpyperidine-1-oxyl(TEMPO)oxidization was developed to modify the porous structure and active groups of wood substrate,and Ru doped Co/CO_(2)P(Ru-Co/CO_(2)P)nanoparticles were encapsulated into the optimized wood carbon substrate(Ru-Co/CO_(2)P@TDCW)for the efficient pH-universal hydrogen evolution reaction(HER).The nanopore and carboxyl groups were produced by delignification and TEMPO oxidation,which accelerated the dispersion and deposition of Ru-Co/CO_(2)P nanoparticles.The RuCo alloy and RuCoP nanoparticles were produced with the doping of Ru,and more Ru-Co/CO_(2)P nanoparticles were anchored by the delignified and TEMPO oxidized wood carbon(TDCW).As anticipated,the Ru-Co/CO_(2)P@TDCW catalyst exhibited excellent pH-universal HER activity,and only 16.6,93,and 43 mV of overpotentials were required to deliver the current density of 50 mA cm^(-2)in alkaline,neutral,and acidic electrolytes,outperforming the noble Pt/C/TDCW catalyst significantly.In addition,Ru-Co/CO_(2)P@TDCW catalyst presented excellent stability for more than 600 h working at 100 mA cm^(-2)in alkaline solution(1.0 M KOH).Density function theory(DFT)results revealed that energy barriers for the dissociation of H_(2)O and the formation of H_(2)were decreased by the doping of Ru,and the conductivity and efficiency of electron migration were also enhanced.This work demonstrated a strategy to optimize the structure and properties of wood carbon substrate,providing a promising strategy to synthesize high-efficiency catalyst for H_(2)production.
基金Funded by the Breeding Project of Anhui Polytechnic University(No.2019YQQ027)the Scientific Research Foundation of Anhui Polytechnic University(No.xjky2022016)+1 种基金the Open Research Found of Anhui Key Laboratory of High-performance Non-ferrous Metal Materials(No.YSJS-2023-07)the Innovative Entrepreneurship Training Program for College Students in Anhui Province(No.S202210363391)。
文摘A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se doping level,a hollow spherical catalyst structure composed of CoSSe was successfully synthesized,which exhibited exceptional activity for hydrogen evolution in acidic solutions.The influences of Se doping on the microstructure and catalytic mechanism of hydrogen evolution reaction(HER)of these composites were systematically investigated.The experimental results reveal that the hollow spherical sample displays an overpotential value of 143 mV along with a Tafel slope value of 69.8 mV·dec^(-1)at a current density of 10 mA·cm^(-2)in an acid aqueous solution.Furthermore,it demonstrates remarkable cycling stability after undergoing 3000 cycles.The comprehensive analysis indicates that Se doping optimizes the electronic structure and enhances conductivity,meanwhile the unique hollow spherical architecture increases active sites for HER and significantly improves overall electrocatalytic performance.
基金supported by the National Natural Science Foundation of China(62404063)the Natural Science Foundation of Heilongjiang Province(YQ2022B008,LH2023A011)+1 种基金the Basic research support plan project for outstanding young teachers in undergraduate universities of Heilongjiang Province(YQJH2023160)the Basic scientific research business expense project of Heilongjiang Provincial Department of Education(2022-KYYWF-0170).
文摘An in-depth understanding of the catalyst surface evolution is crucial for precise control of active sites,yet this aspect has often been overlooked.This study reveals the spontaneous anion regulation mechanism of Br-doped CoP electrocatalysts in the alkaline hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The introduction of Br modulates the electronic structure of the Co site,endowing Br-CoP with a more metallic character.In addition,P ion leaching promotes the in situ reconstruction of Br-CoOOH,which is the real active site for the OER reaction.Meanwhile,the HER situation is different.On the basis of P ion leaching,the leaching of Br ions promotes the formation of CoP-Co(OH)_(2) active species.In addition,Br doping enhances the adsorption of^(*)H,showing excellent H adsorption free energy,thereby greatly improving the HER activity.Simultaneously,it also enhances the adsorption of OOH^(*),effectively facilitating the occurrence of OER reactions.Br-CoP only needs 261 and 76 mV overpotential to drive the current density of 20 mA cm^(-2) and 10 mA^(-2),which can be maintained unchanged for 100 h.This study provides new insights into anion doping strategies and catalyst reconstruction mechanisms.
基金supported by the National Natural Science Foundation of China(Nos.22066017,22272070,W2412067,and 22471155)Jiangxi Province“double thousand plan”project.
文摘The fabrication of efficient and stable catalysts to accelerate the kinetics of the hydrogen evolution reaction(HER)is a crucial step in the development of sustainable energy production.The structural design of Pt-based catalysts with efficient atom utilization remains a pivotal factor in the continued advancement of HER catalysts.In this work,we synthesized phosphorylated Mo-based particles embedded in P-doped carbon materials for the optimized loading of platinum nanoparticles(Pt/Mo-P@C).Theoretical results indicate that the catalytic efficacy of the materials can be enhanced by altering the electronic structure of Pt nanoparticles through the precise formation of Pt-Mo bond and multiple heterostructures.The catalysts exhibited exceptional mass activity after low-temperature reduction,achieving a current density of 100 mA·cm−2 at 54.4 mV,which is lower than that of the commercial Pt/C catalyst.Furthermore,the mass activity of the main catalyst was 6.7 times greater than that of the commercial Pt/C catalyst at an overpotential of 50 mV.
基金supported by the National Science Fund for Distinguished Young Scholars(No.52025041)the National Natural Science Foundation of China(Nos.52474319,52250091,U2341267,and 52450003)+1 种基金the Fundamental Research Funds for the Central Universities(No.FRF-TP-20-02C2)supported by the Interdisciplinary Research Project for Young Teachers of USTB,China(Fundamental Research Funds for the Central Universities)(No.FRF-IDRY-GD23-003).
文摘CoFe bimetallic hydroxides(CoFe BMHs)find wide applications as excellent catalysts in the field of water splitting.However,no study has systematically investigated the influence of the morphologies of CoFe BMHs on catalyst performance.In this study,CoFe BMH nanoflowers(CoFe BMH NFs),CoFe BMH nanosheets(CoFe BMH NSHs),CoFe BMH nanorods(CoFe BMH NRs),and CoFe BMH nanospheres(CoFe BMH NSPs)were prepared on nickel foam via a hydrothermal method.CoFe BMH NSHs exhibited the most beneficial catalytic activity.At a current density of 100 mA·cm^(-2),its overpotential for oxygen evolution reaction(OER)was 282 mV,and the overall water splitting voltage was 2.05 V.The double-layer charging capacitance(Cdl)value of CoFe BMH NSHs was the largest in CoFe BMHs,which proves that CoFe BMH NSHs have the largest active area.Furthermore,the active site in the OER process was metal oxyhydroxide(MOOH)through in situ Raman characterization,and the generation of the active substance was an irreversible process.This work provides important insights into the design of catalyst morphologies and offers valuable guidelines for the enhancement of the performance of other catalysts.
基金supported by the National Research Foundation of Korea(NRF)(NRF-2020M3H4A3106354,NRF-2021M3I3A1083946,and NRF-2021R1A6A3A01087461)the Korea Institute of Science and Technology,and the KISTI Supercomputing Center(KSC-2023-CRE-0492).
文摘Single-atom catalysts(SACs)have garnered interest in designing their ligand environments,facilitating the modification of single catalytic sites toward high activity and selectivity.Despite various synthetic approaches,it remains challenging to achieve a catalytically favorable coordination structure simultaneously with the feasible formation of SACs at low temperatures.Here,a new type of coordination structure for Pt SACs is introduced to offer a highly efficient hydrogen evolution reaction(HER)catalyst,where Pt SACs are readily fabricated by atomically confining PtCl_(2)on chemically driven NO_(2)sites in two-dimensional nitrogen-doped carbon nanosheets at room temperature.The resultant Pt SACs form the NO_(2)-Pt-Cl_(2)coordination structure with an atomic dispersion,as revealed by X-ray spectroscopy and transmission electron microscopy investigations.Moreover,our first-principles density functional theory(DFT)calculations show strong interactions in the coordination by computing the binding energy and charge density difference between PtCl_(2)and NO_(2).Pt SACs,established on the NO_(2)-functionalized carbon support,demonstrate the onset potential of 25 mV,Tafel slope of 40 mV dec^(-1),and high specific activity of 1.35 A mgPt^(-1).Importantly,the Pt SACs also exhibit long-term stability up to 110 h,which is a significant advance in the field of single-atom Pt catalysts.The newly developed coordination structure of Pt SACs features a single Pt active center,providing hydrogen binding ability comparable to that of Pt(111),enhanced long-term durability due to strong metal-support interactions,and the advantage of room-temperature fabrication.
基金supported by the National Natural Science Foundation of China(Nos.22102167 and U21A20317)。
文摘Designing highly active electrocatalysts for the hydrogen evolution reaction(HER)and oxygen evolution and reduction reactions(OER and ORR)is pivotal to renewable energy technology.Herein,based on density functional theory(DFT)calculations,we systematically investigate the catalytic activity of iron-nitrogen-carbon based covalent organic frameworks(COF)monolayers with axially coordinated ligands(denotes as Fe N_(4)-X@COF,X refers to axial ligand,X=-SCN,-I,-H,-SH,-NO_(2),-Br,-ClO,-Cl,-HCO_(3),-NO,-ClO_(2),-OH,-CN and-F).The calculated results demonstrate that all the catalysts possess good thermodynamic and electrochemical stabilities.The different ligands axially ligated to the Fe active center could induce changes in the charge of the Fe center,which further regulates the interaction strength between intermediates and catalysts that governs the catalytic activity.Importantly,FeN_(4)-SH@COF and Fe N_(4)-OH@COF are efficient bifunctional catalysts for HER and OER,FeN_(4)-OH@COF and FeN_(4)-I@COF are promising bifunctional catalysts for OER and ORR.These findings not only reveal promising bifunctional HER/OER and OER/ORR catalysts but also provide theoretical guidance for designing optimum ironnitrogen-carbon based catalysts.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(NRF-2022R1A2C1011559,No.RS-2024-00405818 and NRF-2021M3H4A6A01045764)by the National Supercomputing Center with supercomputing resources including technical support(KSC-2024-CRE-0196)by Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Science and ICT(No.RS-2024-00404712).
文摘Hydrogen evolution reaction(HER)in acidic media has been spotlighted for hydrogen production since it is a favourable kinetics with the supplied protons from a counterpart compared to that within alkaline environment.However,there is no choice but to use a platinum-based catalyst yet.As for a noble metal-free electrocatalyst,incorporation of earth-abundant transition metal(TM)atoms into nanocarbon platforms has been extensively adopted.Although a data-driven methodology facilitates the rational design of TM-anchored carbon catalysts,its practical application suffers from either a simplified theoretical model or the prohibitive cost and complexity of experimental data generation.Herein,an effective and facile catalyst design strategy is proposed based on machine learning(ML)and its model verification using electrochemical methods accompanied by density functional theory simulations.Based on a Bayesian genetic algorithm ML model,the Ni-incorporated carbon quantum dots(Ni@CQD)loaded on a three-dimensional reduced graphene oxide conductor are proposed as the best HER catalyst amongst the various TM-incorporated CQDs under the optimal conditions of catalyst loading,electrode type,and temperature and pH of electrolyte.The ML results are validated with electrochemical experiments,where the Ni@CQD catalyst exhibited superior HER activity,requiring an overpotential of 151 mV to achieve 10 mAcm^(−2) with a Tafel slope of 52 mV dec^(−1) and impressive durability in acidic media up to 100 h.This methodology can provide an effective route for the rational design of highly active electrocatalysts for commercial applications.
基金support from the European Union Horizon 2020 program(project HERMES,nr.952184)the Ministry of Education,Youth and Sports of the Czech Republic for supporting CEMNAT(LM2023037)+1 种基金Czech-NanoLab(LM2023051)infrastructures for providing ALD,SEM,EDX,XPS,TEM,and XRDCzech Science Foundation(project 23-08019X,EXPRO).
文摘Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.
基金supported by the Natural Science Foundation of China(Nos.52022064 and 51971154).
文摘The development of highly active and cost-effective catalysts for the full pH range of the hydrogen evolution reaction(HER)to meet the industrial application demands is an urgent challenge.In this work,the performance and structure–activityrelationships of CuIr alloys prepared by the pulsed laser ablation in liquid technique as full pH range HER catalysts wereinvestigated.Results indicated that Ir is doped into the Cu matrix as single atoms in CuIr-0.1,and CuIr-0.1 single-atom alloys(SAAs)exhibit superior HER performance and stability across the full pH range,with overpotentials of 135,203,and 172 mVat the current density of 10 mA/cm^(2)in acidic,neutral,and alkaline electrolytes,respectively.The enhanced performance ofCuIr-0.1 SAAs can be attributed to the abundant active sites and accelerated reaction kinetics brought about by the electroniceffects.This work successfully alloyed two immiscible metals to improve the catalytic performance,providing an avenue forthe development of highly efficient and versatile HER catalysts for industrial applications.
文摘Hydrogen evolution reaction(HER)is unavoidable in many electrochemical synthesis systems,such as CO_(2)reduction,N2reduction,and H_(2)O_(2)synthesis.It makes those electrochemical reactions with multiple electron-proton transfers more complex when determining kinetics and mass transfer information.Understanding how HER competes with other electrochemical reduction reactions is crucial for both fundamental studies and system performance improvements.In this study,we employed the oxygen reduction reaction(ORR)as a model reaction to investigate HER competition on a polycrystalline-Au surface,using a rotating ring and disk electrode.It’s proved that water molecules serve as the proton source for ORR in alkaline,neutral,and even acidic electrolytes,and a 4-electron process can be achieved when the overpotential is sufficiently high.The competition from H⁺reduction becomes noticeable at the H⁺concentration higher than 2 mmol L^(–1)and intensi-fies as the H^(+)concentration increases.Based on the electrochemical results,we obtained an equivalent circuit diagram for the ORR system with competition from the H+reduction reaction,showing that these reactions occur in parallel and compete with each other.Electrochemical impedance spectroscopy measurements further confirm this argument.Additionally,we discover that the contribution of H+mass transfer to the total H^(+)reduction current is significant and comparable to the kinetic current.We believe this work will deepen our understanding of HER and its competition in electrochemical reduction systems.
