Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated therma...Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated thermal conditions,sluggish dehydrogena-tion kinetics,and high thermodynamic stability,limit its practical application.One effective method of addressing these challenges is cata-lyst doping,which effectively boosts the hydrogen storage capability of Mg-based materials.Herein,we review recent advancements in catalyst-doped MgH_(2) composites,with particular focus on multicomponent and high-entropy catalysts.Structure-property relationships and catalytic mechanisms in these doping strategies are also summarized.Finally,based on existing challenges,we discuss future research directions for the development of Mg-based hydrogen storage systems.展开更多
Hydrogen production via catalytic reforming of renewable fuels represents a pivotal strategy in the decarbonization of energy systems.However,conventional catalysts continue to encounter persistent challenges,includin...Hydrogen production via catalytic reforming of renewable fuels represents a pivotal strategy in the decarbonization of energy systems.However,conventional catalysts continue to encounter persistent challenges,including sintering,carbon deposition,and structural degradation under severe reaction conditions.This review addresses the growing need to consolidate the rapidly expanding body of knowledge on medium-and high-entropy materials(MEMs and HEMs),whose unique thermodynamic features position them as next-generation catalysts with the potential to overcome these limitations.The discussion is organized to examine how entropy stabilizatio n,lattice disto rtion,and multi-elemental synergy influence catalytic behavior.Materials are categorized by crystal structure(e.g.,perovskite,spinel,and periclase)and by their roles in key reforming processes,including steam,dry,partial oxidation,and autothermal reforming of renewable fuels such as bioethanol,biomethane,and methanol.A detailed comparison of synthesis methods,configurational entropy thresholds,and physicochemical characteristics is presented.The review synthesizes key insights from recent studies,including advances in exsolution-driven nanostructuring,the impact of oxygen vacancy engineering,and the performance of entropy-optimized compositions under practical reforming conditions.It offers a comprehensive mapping of structureperformance relationships,underscoring how entropy can be harnessed to design more robust,selective,and efficient catalytic systems.Future perspectives emphasize the exploration of underinvestigated entropy-stabilized systems(e.g.,nitrides and sulfides),the integration of data-driven design approaches,and the imperative for long-term stability evaluations under industrially relevant conditions.Finally,the review highlights promising opportunities for scaling up entropy-based catalysts and aligning their development with techno-economic and environmental benchmarks.This work aims to serve as both a comprehensive reference and a strategic outlook for advancing hydrogen production technologies through entropy-engineered catalysis.展开更多
Due to unique electrical properties and high catalytic efficiency,transition metal nitrogen-codoped car-bide(TM-N-C)has attracted tremendous interest as a multifunctional electrocatalyst for water splitting.Unlike tra...Due to unique electrical properties and high catalytic efficiency,transition metal nitrogen-codoped car-bide(TM-N-C)has attracted tremendous interest as a multifunctional electrocatalyst for water splitting.Unlike traditional single-source modification,herein a novel pomegranate-like high-entropy(HE)elec-trocatalyst of Ni_(3)ZnC_(0.7)decorated with homogeneous multimetal(Fe,Co,Cu,and Ni)nitrogen-codoped carbon matrix(Ni_(3)ZnC_(0.7)@CoNiCuFe-NC)is reported.It can be implemented by the simple thermal an-nealing method of multimetal codoped zeolitic imidazolate framework(ZIF).Benefiting from the syn-ergistic effects of plentiful TM-N-C species,template effect of ZIF and distinct nanoporous structure,HE electrocatalyst Ni_(3)ZnC_(0.7)@CoNiCuFe-NC exhibits outstanding electrocatalytic performance.When ap-plied in strong alkaline electrolyte(1.0 M KOH),the overpotentials of Ni_(3)ZnC_(0.7)@CoNiCuFe-NC present as low as 202 and 97 mV for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)at 10 mA cm^(−2)current density.Surprisingly as a bifunctional electrode,it can achieve the low cell voltage of 1.53 V at 10 mA cm^(−2)current density for overall water splitting,which is comparable to conventional IrO_(2)||Pt/C electrode and superior to the recently reported analogous bifunctional catalysts.Thus,the work proposes the direction for the rational design of homogeneous distribution of TM-N-C material for water splitting in the green hydrogen energy industry.展开更多
The development of efficient catalysts for selective organic transformations has emerged as a paramount research frontier in recent years.High-entropy catalysts(HECs)have emerged as a transformative platform for selec...The development of efficient catalysts for selective organic transformations has emerged as a paramount research frontier in recent years.High-entropy catalysts(HECs)have emerged as a transformative platform for selective electrocatalytic organic transformations(EOTs),characterized by their abundance of active sites,adjustable specific surface areas,stable crystal structures,exceptional geometric compatibility,and unique electronic balance factors.Despite demonstrating exceptional promise for commercial exploitation,HECs for highly efficient EOTs lack systematic reviews.This review begins with a comprehensive discussion of the fundamental properties of HECs,encompassing their conceptual definitions,structural features,and the development of progressive synthesis and characterization techniques.Subsequently,it underscores the versatile implementation of selective organic transformations across diverse HECs,particularly in alcohol oxidation and biomass conversion reactions.Finally,this review systematically evaluates both the promising opportunities and key challenges in the development of high-efficiency HECs-based electrocatalytic systems for selective organic transformations.This timely overview of recent advancements in HECs-driven EOTs is anticipated to inspire the rational design of advanced high-entropy materials,enabling enhanced performance across diverse redox-catalyzed selective organic transformations of valuable feedstocks and related processes.展开更多
High-entropy materials(HEMs)have attracted extensive attention in the field of electrocatalysis due to their high performance enabled by their multi-component,tunable structural characteristics and excellent stability...High-entropy materials(HEMs)have attracted extensive attention in the field of electrocatalysis due to their high performance enabled by their multi-component,tunable structural characteristics and excellent stability.HEMs are usually composed of five or more metal elements,and have core advantages such as high configurational entropy,lattice distortion and multi-element synergistic effect,which provide new possibilities for composition regulation and performance optimization of catalysts.Especially at the nanoscale,HEMs show a larger specific surface area,abundant active sites and higher catalytic reaction efficiency,further expanding their application potential in electrochemical reactions.This paper systematically reviews the classification,structure construction and regulation strategies of HEMs,and focuses on their research progress in critical electrocatalytic reactions including water splitting(HER,OER),hydrogen oxidation(HOR),oxygen reduction(ORR),carbon dioxide reduction(CO_(2)RR),nitrate reduction(NO_(3)-RR)and electrooxidation of organics(EOO).In addition,the preparation methods of HEMs,the structure-performance relationship and the entropy regulation mechanism in the catalytic process are analyzed.Finally,this paper proposes the key challenges currently faced by HEMs in electrocatalytic applications and looks forward to their future development direction,providing a theoretical basis and design ideas for building a new generation of efficient and sustainable electrocatalysts.展开更多
High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of...High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of phosphides.Herein,electrospinning and in situ phosphating were employed to prepare three-dimensional(3D)networks of self-supporting HEMP nanofibers with varying degrees of phosphate content.Comprehensive characterizations via X-ray diffraction and X-ray photoelectron spectroscopy,as well as density functional theory calculations,demonstrate that the introduction of phosphorus(P)atoms to HEMP carbon nanofibers mediates their electronic structure,leads to lattice expansion,which in turn enhances their catalytic performance in the hydrogen evolution reaction(HER).Moreover,the formation of metal-P bonds weakens metal-metal interaction and decreases the free energy of hydrogen adsorption,contributing to the exceptional activity observed in the HEMP catalyst.Electrochemical measurements demonstrate that the HEMP-0.75 catalyst with an ultralow loading of 1.22 wt%ruthenium(Ru)exhibits the highest HER catalytic activity and stability in a 1 M KOH electrolyte,achieving a minimal overpotential of 26 mV at a current density of 10 mA·cm^(-2)and Tafel slope of 50.9 mV·dec^(-1).展开更多
Electrocatalysts are an effective strategy to mitigate the shuttling effect of lithium polysulfides(LiPSs)and accelerate the redox kinetics of LiPSs in lithium-sulfur(Li-S)batteries.However,traditional electrocatalyst...Electrocatalysts are an effective strategy to mitigate the shuttling effect of lithium polysulfides(LiPSs)and accelerate the redox kinetics of LiPSs in lithium-sulfur(Li-S)batteries.However,traditional electrocatalysts only have a single active site and often undergo structural collapse and aggregation during charging and discharging,resulting in reduced catalytic performance.Herein,the two-dimensional(2D)polar high-entropy La_(0.71)Sr_(0.29)Co_(0.21)Ni_(0.20)Fe_(0.19)Cr_(0.20)Cu_(0.20)O_(3)(LCO-HEO)nanosheets were rationally designed and successfully synthesized to address this issue.The distinct functional polar sites in LCOHEOs were formed by the d-d orbital hybridization between spatially coupling adjacent transition metals,which can strengthen the dipole-dipole interaction between polar LCO-HEOs and polar LiPSs.2D polar LCO-HEO nanosheets can efficiently capture and trigger the tandem catalysis of polar LiPSs during their sequential conversion.The S/LCO-HEO composite cathode exhibits a high specific capacity of 1161.1 mA h g^(-1)at 1.0 C,with an ultralow capacity attenuation rate of 0.036%per cycle over 1200 cycles,and achieves stable cycling for 1500 cycles even at 8.0 C.Furthermore,even with a high sulfur loading(5.5 mg cm^(-2))and a low electrolyte/sulfur(E/S)ratio(4.0μL mg^(-1)),the S/LCO-HEO composite cathode shows desirable sulfur utilization and good cycle stability.This work demonstrates the feasibility of high entropy-driven multiple distinct functional polar sites for high-rate and long-cycle Li-S batteries.展开更多
Ammonia borane(AB)is a promising hydrogen storage medium widely used for hydrogen generation,but its slow hydrolysis kinetics limits its applications.Medium/high-entropy materials(M/HEMs)have emerged as efficient cata...Ammonia borane(AB)is a promising hydrogen storage medium widely used for hydrogen generation,but its slow hydrolysis kinetics limits its applications.Medium/high-entropy materials(M/HEMs)have emerged as efficient catalysts due to their complementary elemental and structural properties.We developed a deposition in-situ reduction(D-ISR)approach for the rapid synthesis of single-phase medium/high-entropy oxides(M/HEOs)at room temperature,along with establishing general criteria for M/HEOs synthesis based on component properties.Deposition facilitates the incorporation of active elements(Ti/Zr/V/Cr/Nb),which significantly enhance the enthalpy-driven force of the dynamic oxidation(DO)process via an“active element coordination”strategy,thereby overcoming low-temperature solid solubility limitations.Nine-component HEOs and large-scale experiments confirm the universality and mass-production potential of the D-ISR approach.CoCuNiTi-O/AC synthesized via this strategy exhibits pronounced crystal distortion and disorder(Co–O coordination number=10.2),enhancing the Co–O coordination environment and mitigating Ostwald ripening.This leads to high activity and significantly enhanced structural stability,achieving a turnover frequency of 236.6 min^(-1)for ammonia borane hydrolysis,15 times higher than Co-O/AC and surpassing the most non-noble catalysts.These observations highlight an efficient M/HEOs synthesis methodology that advances M/HEMs applications in nanoenergy.展开更多
The effect of element Ti on the microstructures and mechanical properties of as-cast and annealed NbTaMoWTi,(x=0,1,1.5,2)refractory high-entropy alloys(RHEAs)was investigated.Results show that after Ti addition,the as...The effect of element Ti on the microstructures and mechanical properties of as-cast and annealed NbTaMoWTi,(x=0,1,1.5,2)refractory high-entropy alloys(RHEAs)was investigated.Results show that after Ti addition,the as-cast alloys maintain their original single body-centered cubic(bcc)structure.As for the mechanical properties,compared with those without Ti addition,the strength and ductility of NbTaMoWTi,alloys increase by 93%and 215%,respectively.Furthermore,the NbTaMoWTi alloys exhibit outstanding thermal stability.After annealing at 1400 C,they still maintain the single bcc structure,and their mechanical properties are even slightly improved.However,annealing leads to a significant deterioration in the mechanical properties of high-Ti-content alloys(NbTaMoWTil and NbTaMoWTi2),owing to the formation of Ti-rich acicular phases.展开更多
In this study,FeCr_(x)MnAlCu(x=0,0.5,1.0,1.5,2.0)high-entropy alloys were fabricated using vacuum arc melting,and the corrosion behavior of these alloys in 3.5wt%NaCl solution at room temperature was investigated by e...In this study,FeCr_(x)MnAlCu(x=0,0.5,1.0,1.5,2.0)high-entropy alloys were fabricated using vacuum arc melting,and the corrosion behavior of these alloys in 3.5wt%NaCl solution at room temperature was investigated by electrochemical dynamic potential polarization curves and immersion experiments.The microstructure results show that the high-entropy alloy with x=0 has a body-centered cubic phase structure,whereas the high-entropy alloys with x=0.5–2.0 have a mixed face-centered cubic+body-centered cubic dual-phase structure.The corrosion results show that the corrosion resistance of the high-entropy alloy is increased with the increase in Cr content.Among them,the high-entropy alloy with x=2.0 exhibits the optimal corrosion resistance:the highest self-corrosion potential(E_(corr)=−0.354 V vs.Ag/AgCl),the smallest self-corrosion current density(I_(corr)=1.991×10^(−6)A·cm^(−2)),and the smallest corrosion rate(0.0292 mm/a).The composite passivation film of oxides and hydroxides is formed on the surface of the corroded high-entropy alloys,and the Cr_(2)O_(3)content is increased with the increase in Cr content,which effectively improves the stability and protective properties of the passivation film.展开更多
The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing t...The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing to this multi-principal element nature,high-entropy alloys exhibit complex deformation behavior dominated by alternating and coupled deformation mechanisms.Therefore,elucidating these intricate deformation mechanisms remains a key challenge in current research.Neutron diffraction(ND)techniques offer distinct advantages over traditional microscopic methods for characterizing such complex deformation behavior.The strong penetration capability of neutrons enables in-situ,real-time,and non-destructive detection of structural evolution in most centimeter-level bulk samples under complex environments,and ND allows precise characterization of lattice site occupations for light elements,such as C and O,and neighboring elements.This review discussed the principles of ND,experiment procedures,and data analysis.Combining with recent advances in the research about face-centered cubic high-entropy alloy,typical examples of using ND to investigate the deformation behavior were summarized,ultimately revealing deformation mechanisms dominated by dislocations,stacking faults,twinning,and phase transformations.展开更多
Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prep...Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prepared,and the influence mechanism of additives on the structure-performance relationship of the catalysts was systematically explored.Through a variety of characterization methods such as XRD,N2 physical adsorption-desorption,TEM,H_(2)-TPR,CO_(2)-TPD and XPS,combined with catalytic performance evaluation experiments,the correlation between the microstructure of catalysts and the reaction performance of CO_(2)hydrogenation to methanol was analyzed in depth.The results show that metal additives significantly improve the performance of catalysts.After the introduction of additives,the specific surface area and pore volume of the catalysts increase,the grain size of Cu decreases,and its dispersion improves.The Ce-modified CZC catalyst exhibited the best performance,with the grain size of CuO as small as 11.41 nm,and the surface oxygen vacancy concentration(OⅡ/OⅠ=3.15)was significantly higher than that of other samples.The reaction performance test shows that under the conditions of 2.8 MPa,8000 h−1 and 280℃,the CO_(2)conversion of the CZC catalyst reached 18.83%,the methanol selectivity was 68.40%,and the methanol yield was 12.88%,all of which are superior to other catalysts.Its excellent performance can be attributed to the fact that CeO_(2)enhances the metal-support interaction,increases the surface basicity,promotes the adsorption and activation of CO_(2),and simultaneously inhibits the reverse water-gas shift side reaction.This study clarifies the structure-activity regulation mechanism of additive modification on Cu-ZnO catalysts,providing a theoretical basis and technical reference for the development of efficient catalysts for CO_(2)hydrogenation to methanol.展开更多
In this paper,the Ni/Al_(2)O_(3) monolithic catalyst with 15%Ni content was prepared using cordierite as a matrix,and the catalyst was modified with 10%NaOH to study the methanation performance of biomass gasification...In this paper,the Ni/Al_(2)O_(3) monolithic catalyst with 15%Ni content was prepared using cordierite as a matrix,and the catalyst was modified with 10%NaOH to study the methanation performance of biomass gasification simulated gas based on alkali-modified Ni/Al_(2)O_(3) monolithic catalyst.BET,TEM,H_(2)-TPR,XRD,CO_(2)-TPD and TG were used to characterize the physicochemical properties of the catalyst before and after modification.The results indicated that the CO conversion rate trends of unmodified and modified Ni/Al_(2)O_(3) monolithic catalysts over 2 h were fundamentally consistent.However,the Ni/Al_(2)O_(3) catalysts modified for 2 h demonstrated significantly enhanced performance compared to those modified for 1 h.Regarding CH4 selectivity,the modified Ni/Al_(2)O_(3) catalyst exhibited markedly better performance than the unmodified Ni/Al_(2)O_(3) catalyst,confirming the enhanced methane performance of the alkali-modified Ni/Al_(2)O_(3) monolithic catalyst.Under optimized conditions(H_(2)/CO volume ratio of 3∶1,space velocity of 10000 mL/(g·h),and temperature of 400℃),the methanation performance of the Ni/Al_(2)O_(3) monolithic catalyst modified for 2 h reached its peak,achieving a CO conversion rate of 97%with 100%CH4 selectivity.展开更多
Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting t...Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting two greenhouse gases(methane and carbon dioxide)into syngas and its promising industrial applications.Nickel(Ni)-based catalysts,with high catalytic activity,low cost,and abundant resources,are considered ideal candidates for industrial applications.In this article,three reaction kinetic models were briefly introduced,namely the Power-Law(PL)model,the Eley-Rideal(ER)model,and the Langmuir-Hinshelwood-Hougen-Watson(LHHW)model.Based on the LHHW model,the reaction kinetics and mechanisms of different catalytic systems were systematically discussed,including the properties of supports,the doping of noble metals and transition metals,the role of promoters,and the influence of the geometric and electronic structures of Ni on the reaction mechanism.Furthermore,the kinetics of carbon deposition and elimination on various catalysts were analyzed.Based on the reaction rate expressions for carbon elimination,the reasons for the high activity of transition metal iron(Fe)-doped catalysts and core-shell structured catalysts in carbon elimination were explained.Based on the detailed collation and comparative analysis of the reaction mechanisms and kinetic characteristics across diverse Ni-based catalytic systems,a theoretical guidance for the designing of high-performance catalysts was provided in this work.展开更多
Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen e...Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen evolution reaction(HER)and the anodic oxygen evolution reaction(OER).Transition metal-based catalysts have garnered significant research interest as promising alternatives to noble-metal catalysts,owing to their low cost,tunable composition,and noble-metal-like catalytic activity.Nevertheless,systematic reviews on their application as bifunctional catalysts for overall water splitting(OWS)are still limited.This review comprehensively outlines the principal categories of bifunctional transition metal electrocatalysts derived from electrospun nanofibers(NFs),including metals,oxides,phosphides,sulfides,and carbides.Key strategies for enhancing their catalytic performance are systematically summarized,such as heterointerface engineering,heteroatom doping,metal-nonmetal-metal bridging architectures,and single-atom site design.Finally,current challenges and future research directions are discussed,aiming to provide insightful perspectives for the rational design of high-performance electrocatalysts for OWS.展开更多
CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the ca...CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the catalytic mechanism of Cu species in the CZA catalyst remains a great challenge.In this study,we systematically investigated the valence state change of active Cu species in CZA catalyst and their influence on catalytic performance by modifying the catalysts with varying amounts of electron donor K,thus identifying the catalytic function of Cu species with different valence states.H2-TPR,XPS and HR-TEM characterizations reveal that the highly dispersed K species supported on CZA catalysts will inhibit the reduction of CuO,resulting in a small amount of Cu_(2)O active species being produced under reaction conditions thus causing a decrease in catalytic activity.Furthermore,XRD and Cu LMM spectra show that the proportion of Cu^(0) in K-modified CZA catalysts increases with K loading,but a higher proportion of Cu^(0) species on the surface obviously promotes the reverse water gas shift(RWGS)reaction.According to the results of in situ infrared spectroscopy,CZA catalyst follows the reaction pathway mediated by HCOO^(*)in the hydrogenation of CO_(2) to methanol.展开更多
Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catal...Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.展开更多
Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon...Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.展开更多
To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction...Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction(ORR)and chlorideinduced degradation over conventional catalysts.In this study,we proposed a universal synthetic strategy to construct heteroatom axially coordinated Fe–N_(4) single-atom seawater catalyst materials(Cl–Fe–N_(4) and S–Fe–N_(4)).X-ray absorption spectroscopy confirmed their five-coordinated square pyramidal structure.Systematic evaluation of catalytic activities revealed that compared with S–Fe–N_(4),Cl–Fe–N_(4) exhibits smaller electrochemical active surface area and specific surface area,yet demonstrates higher limiting current density(5.8 mA cm^(−2)).The assembled zinc-air batteries using Cl–Fe–N_(4) showed superior power density(187.7 mW cm^(−2) at 245.1 mA cm^(−2)),indicating that Cl axial coordination more effectively enhances the intrinsic ORR activity.Moreover,Cl–Fe–N_(4) demonstrates stronger Cl−poisoning resistance in seawater environments.Chronoamperometry tests and zinc-air battery cycling performance evaluations confirmed its enhanced stability.Density functional theory calculations revealed that the introduction of heteroatoms in the axial direction regulates the electron center of Fe single atom,leading to more active reaction intermediates and increased electron density of Fe single sites,thereby enhancing the reduction in adsorbed intermediates and hence the overall ORR catalytic activity.展开更多
基金financially supported by the National Key Research and Development Program of China (No. 2021YFB4000604)the National Natural Science Foundation of China (No. 52271220)+2 种基金the 111 Project (No. B12015)the Fundamental Research Funds for the Central UniversitiesHaihe Laboratory of Sustainable Chemical Transformations, Guangxi Collaborative Innovation Centre of Structure and Property for New Energy and Materials, Science Research and Technology Development Project of Guilin (No. 20210102-4)
文摘Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated thermal conditions,sluggish dehydrogena-tion kinetics,and high thermodynamic stability,limit its practical application.One effective method of addressing these challenges is cata-lyst doping,which effectively boosts the hydrogen storage capability of Mg-based materials.Herein,we review recent advancements in catalyst-doped MgH_(2) composites,with particular focus on multicomponent and high-entropy catalysts.Structure-property relationships and catalytic mechanisms in these doping strategies are also summarized.Finally,based on existing challenges,we discuss future research directions for the development of Mg-based hydrogen storage systems.
基金support of??mbar Energia(PD-00211-0003/2023)the strategic importance of the support given by ANEEL(The Brazilian National Electric Energy)through the R&D levy regulation financial support provided by various Brazilian funding agencies,including FAPESP(2023/17560-0,2017/11958-1,and 2017/11986-5),FUNDEP(27192*36,27192*78,27192*79,and 27192*82),CAPES,and CNPq(405643/2022-5 and 302180/2022-2)。
文摘Hydrogen production via catalytic reforming of renewable fuels represents a pivotal strategy in the decarbonization of energy systems.However,conventional catalysts continue to encounter persistent challenges,including sintering,carbon deposition,and structural degradation under severe reaction conditions.This review addresses the growing need to consolidate the rapidly expanding body of knowledge on medium-and high-entropy materials(MEMs and HEMs),whose unique thermodynamic features position them as next-generation catalysts with the potential to overcome these limitations.The discussion is organized to examine how entropy stabilizatio n,lattice disto rtion,and multi-elemental synergy influence catalytic behavior.Materials are categorized by crystal structure(e.g.,perovskite,spinel,and periclase)and by their roles in key reforming processes,including steam,dry,partial oxidation,and autothermal reforming of renewable fuels such as bioethanol,biomethane,and methanol.A detailed comparison of synthesis methods,configurational entropy thresholds,and physicochemical characteristics is presented.The review synthesizes key insights from recent studies,including advances in exsolution-driven nanostructuring,the impact of oxygen vacancy engineering,and the performance of entropy-optimized compositions under practical reforming conditions.It offers a comprehensive mapping of structureperformance relationships,underscoring how entropy can be harnessed to design more robust,selective,and efficient catalytic systems.Future perspectives emphasize the exploration of underinvestigated entropy-stabilized systems(e.g.,nitrides and sulfides),the integration of data-driven design approaches,and the imperative for long-term stability evaluations under industrially relevant conditions.Finally,the review highlights promising opportunities for scaling up entropy-based catalysts and aligning their development with techno-economic and environmental benchmarks.This work aims to serve as both a comprehensive reference and a strategic outlook for advancing hydrogen production technologies through entropy-engineered catalysis.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.22008180 and 21878231)the Natural Science Foundation of Tianjin(Nos.19JCQNJC05700 and 19JCZDJC37300)the Tianjin College Student Innovation and Entrepreneurship Training Program(No.202010058034).This work was also supported by the Analytical&Testing Center of Tiangong University for structural characterization tests.
文摘Due to unique electrical properties and high catalytic efficiency,transition metal nitrogen-codoped car-bide(TM-N-C)has attracted tremendous interest as a multifunctional electrocatalyst for water splitting.Unlike traditional single-source modification,herein a novel pomegranate-like high-entropy(HE)elec-trocatalyst of Ni_(3)ZnC_(0.7)decorated with homogeneous multimetal(Fe,Co,Cu,and Ni)nitrogen-codoped carbon matrix(Ni_(3)ZnC_(0.7)@CoNiCuFe-NC)is reported.It can be implemented by the simple thermal an-nealing method of multimetal codoped zeolitic imidazolate framework(ZIF).Benefiting from the syn-ergistic effects of plentiful TM-N-C species,template effect of ZIF and distinct nanoporous structure,HE electrocatalyst Ni_(3)ZnC_(0.7)@CoNiCuFe-NC exhibits outstanding electrocatalytic performance.When ap-plied in strong alkaline electrolyte(1.0 M KOH),the overpotentials of Ni_(3)ZnC_(0.7)@CoNiCuFe-NC present as low as 202 and 97 mV for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)at 10 mA cm^(−2)current density.Surprisingly as a bifunctional electrode,it can achieve the low cell voltage of 1.53 V at 10 mA cm^(−2)current density for overall water splitting,which is comparable to conventional IrO_(2)||Pt/C electrode and superior to the recently reported analogous bifunctional catalysts.Thus,the work proposes the direction for the rational design of homogeneous distribution of TM-N-C material for water splitting in the green hydrogen energy industry.
基金supported by the National Natural Science Foundation of China(22479104,22209029,U24A20541,22278094,and W2421038)National Key Research and Development Program of China(2022YFC3003405)+1 种基金Central government guided local science and technology development fund project(YDZJSX2025D027)Open Fund(PLN2023-7)of National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)。
文摘The development of efficient catalysts for selective organic transformations has emerged as a paramount research frontier in recent years.High-entropy catalysts(HECs)have emerged as a transformative platform for selective electrocatalytic organic transformations(EOTs),characterized by their abundance of active sites,adjustable specific surface areas,stable crystal structures,exceptional geometric compatibility,and unique electronic balance factors.Despite demonstrating exceptional promise for commercial exploitation,HECs for highly efficient EOTs lack systematic reviews.This review begins with a comprehensive discussion of the fundamental properties of HECs,encompassing their conceptual definitions,structural features,and the development of progressive synthesis and characterization techniques.Subsequently,it underscores the versatile implementation of selective organic transformations across diverse HECs,particularly in alcohol oxidation and biomass conversion reactions.Finally,this review systematically evaluates both the promising opportunities and key challenges in the development of high-efficiency HECs-based electrocatalytic systems for selective organic transformations.This timely overview of recent advancements in HECs-driven EOTs is anticipated to inspire the rational design of advanced high-entropy materials,enabling enhanced performance across diverse redox-catalyzed selective organic transformations of valuable feedstocks and related processes.
基金supported by the National Natural Science Foundation of China(22378247 and 22078187)China-CEEC University Joint Education Project(2021099)+1 种基金the International Joint Research Center for Biomass Chemistry and Materials,the Shaanxi International Science and Technology Cooperation Base(2018GHJD-19)Ning Wei and Xue Yao are grateful to Innovative Talents International Cooperative Training Project from China Scholarship Council(Grant No.202310470014 and 202310470013).
文摘High-entropy materials(HEMs)have attracted extensive attention in the field of electrocatalysis due to their high performance enabled by their multi-component,tunable structural characteristics and excellent stability.HEMs are usually composed of five or more metal elements,and have core advantages such as high configurational entropy,lattice distortion and multi-element synergistic effect,which provide new possibilities for composition regulation and performance optimization of catalysts.Especially at the nanoscale,HEMs show a larger specific surface area,abundant active sites and higher catalytic reaction efficiency,further expanding their application potential in electrochemical reactions.This paper systematically reviews the classification,structure construction and regulation strategies of HEMs,and focuses on their research progress in critical electrocatalytic reactions including water splitting(HER,OER),hydrogen oxidation(HOR),oxygen reduction(ORR),carbon dioxide reduction(CO_(2)RR),nitrate reduction(NO_(3)-RR)and electrooxidation of organics(EOO).In addition,the preparation methods of HEMs,the structure-performance relationship and the entropy regulation mechanism in the catalytic process are analyzed.Finally,this paper proposes the key challenges currently faced by HEMs in electrocatalytic applications and looks forward to their future development direction,providing a theoretical basis and design ideas for building a new generation of efficient and sustainable electrocatalysts.
基金supported by the National Natural Science Foundation of China(Nos.22103045 and 52273077)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZDKT202108,RZ2000003334 and G2RC202022)support from the Australian National Fabrication Facility’s Queensland Node(No.ANFF-Q),the UQ-Yonsei International Research Project,and the JST-ERATO Yamauchi Materials Space-Tectonics Project(No.JPMJER2003).
文摘High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of phosphides.Herein,electrospinning and in situ phosphating were employed to prepare three-dimensional(3D)networks of self-supporting HEMP nanofibers with varying degrees of phosphate content.Comprehensive characterizations via X-ray diffraction and X-ray photoelectron spectroscopy,as well as density functional theory calculations,demonstrate that the introduction of phosphorus(P)atoms to HEMP carbon nanofibers mediates their electronic structure,leads to lattice expansion,which in turn enhances their catalytic performance in the hydrogen evolution reaction(HER).Moreover,the formation of metal-P bonds weakens metal-metal interaction and decreases the free energy of hydrogen adsorption,contributing to the exceptional activity observed in the HEMP catalyst.Electrochemical measurements demonstrate that the HEMP-0.75 catalyst with an ultralow loading of 1.22 wt%ruthenium(Ru)exhibits the highest HER catalytic activity and stability in a 1 M KOH electrolyte,achieving a minimal overpotential of 26 mV at a current density of 10 mA·cm^(-2)and Tafel slope of 50.9 mV·dec^(-1).
基金supported by grants from the National Natural Science Foundation of China(52072099)Team program of the Natural Science Foundation of Heilongjiang Province,China(No.TD2021E005)Joint Guidance Project of the Natural Science Foundation of Heilongjiang Province,China(No.LH2022E093)。
文摘Electrocatalysts are an effective strategy to mitigate the shuttling effect of lithium polysulfides(LiPSs)and accelerate the redox kinetics of LiPSs in lithium-sulfur(Li-S)batteries.However,traditional electrocatalysts only have a single active site and often undergo structural collapse and aggregation during charging and discharging,resulting in reduced catalytic performance.Herein,the two-dimensional(2D)polar high-entropy La_(0.71)Sr_(0.29)Co_(0.21)Ni_(0.20)Fe_(0.19)Cr_(0.20)Cu_(0.20)O_(3)(LCO-HEO)nanosheets were rationally designed and successfully synthesized to address this issue.The distinct functional polar sites in LCOHEOs were formed by the d-d orbital hybridization between spatially coupling adjacent transition metals,which can strengthen the dipole-dipole interaction between polar LCO-HEOs and polar LiPSs.2D polar LCO-HEO nanosheets can efficiently capture and trigger the tandem catalysis of polar LiPSs during their sequential conversion.The S/LCO-HEO composite cathode exhibits a high specific capacity of 1161.1 mA h g^(-1)at 1.0 C,with an ultralow capacity attenuation rate of 0.036%per cycle over 1200 cycles,and achieves stable cycling for 1500 cycles even at 8.0 C.Furthermore,even with a high sulfur loading(5.5 mg cm^(-2))and a low electrolyte/sulfur(E/S)ratio(4.0μL mg^(-1)),the S/LCO-HEO composite cathode shows desirable sulfur utilization and good cycle stability.This work demonstrates the feasibility of high entropy-driven multiple distinct functional polar sites for high-rate and long-cycle Li-S batteries.
基金the financial support from the National Natural Science Foundation of China(52171223)the Guangxi Science and Technology Major Project(No.AA24206007)。
文摘Ammonia borane(AB)is a promising hydrogen storage medium widely used for hydrogen generation,but its slow hydrolysis kinetics limits its applications.Medium/high-entropy materials(M/HEMs)have emerged as efficient catalysts due to their complementary elemental and structural properties.We developed a deposition in-situ reduction(D-ISR)approach for the rapid synthesis of single-phase medium/high-entropy oxides(M/HEOs)at room temperature,along with establishing general criteria for M/HEOs synthesis based on component properties.Deposition facilitates the incorporation of active elements(Ti/Zr/V/Cr/Nb),which significantly enhance the enthalpy-driven force of the dynamic oxidation(DO)process via an“active element coordination”strategy,thereby overcoming low-temperature solid solubility limitations.Nine-component HEOs and large-scale experiments confirm the universality and mass-production potential of the D-ISR approach.CoCuNiTi-O/AC synthesized via this strategy exhibits pronounced crystal distortion and disorder(Co–O coordination number=10.2),enhancing the Co–O coordination environment and mitigating Ostwald ripening.This leads to high activity and significantly enhanced structural stability,achieving a turnover frequency of 236.6 min^(-1)for ammonia borane hydrolysis,15 times higher than Co-O/AC and surpassing the most non-noble catalysts.These observations highlight an efficient M/HEOs synthesis methodology that advances M/HEMs applications in nanoenergy.
基金National Natural Science Foundation of China(51774179)Natural Science Foundation of Liaoning Province(20180550546)+2 种基金Joint Fund of State Key Laboratory of Metal Material for Marine Equipment and Application(HGSKL-USTLN(2021)03)High-Level Talent Fund of USTL(6003000377,6003000294)supported by Liaoning Provincial Department of Education(LJ212410146037)。
文摘The effect of element Ti on the microstructures and mechanical properties of as-cast and annealed NbTaMoWTi,(x=0,1,1.5,2)refractory high-entropy alloys(RHEAs)was investigated.Results show that after Ti addition,the as-cast alloys maintain their original single body-centered cubic(bcc)structure.As for the mechanical properties,compared with those without Ti addition,the strength and ductility of NbTaMoWTi,alloys increase by 93%and 215%,respectively.Furthermore,the NbTaMoWTi alloys exhibit outstanding thermal stability.After annealing at 1400 C,they still maintain the single bcc structure,and their mechanical properties are even slightly improved.However,annealing leads to a significant deterioration in the mechanical properties of high-Ti-content alloys(NbTaMoWTil and NbTaMoWTi2),owing to the formation of Ti-rich acicular phases.
基金Gansu Provincial Science and Technology Major Special Program(24ZDWA008)Fourth Batch of Top Leading Talents Fund Projects in Gansu Province(ZZ2023G50100013)。
文摘In this study,FeCr_(x)MnAlCu(x=0,0.5,1.0,1.5,2.0)high-entropy alloys were fabricated using vacuum arc melting,and the corrosion behavior of these alloys in 3.5wt%NaCl solution at room temperature was investigated by electrochemical dynamic potential polarization curves and immersion experiments.The microstructure results show that the high-entropy alloy with x=0 has a body-centered cubic phase structure,whereas the high-entropy alloys with x=0.5–2.0 have a mixed face-centered cubic+body-centered cubic dual-phase structure.The corrosion results show that the corrosion resistance of the high-entropy alloy is increased with the increase in Cr content.Among them,the high-entropy alloy with x=2.0 exhibits the optimal corrosion resistance:the highest self-corrosion potential(E_(corr)=−0.354 V vs.Ag/AgCl),the smallest self-corrosion current density(I_(corr)=1.991×10^(−6)A·cm^(−2)),and the smallest corrosion rate(0.0292 mm/a).The composite passivation film of oxides and hydroxides is formed on the surface of the corroded high-entropy alloys,and the Cr_(2)O_(3)content is increased with the increase in Cr content,which effectively improves the stability and protective properties of the passivation film.
基金National Key R&D Program of China(2023YFB3711904,2022YFA1603801)National Natural Science Foundation of China(12404230,52471181,52301213,52130108,52471005)+2 种基金National Nature Science Foundation of Zhejiang Province(LY23E010002)Open Fund of the China Spallation Neutron Source,Songshan Lake Science City(KFKT2023B11)Guangdong Basic and Applied Basic Research Foundation(2022A1515110805,2024A1515010878)。
文摘The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing to this multi-principal element nature,high-entropy alloys exhibit complex deformation behavior dominated by alternating and coupled deformation mechanisms.Therefore,elucidating these intricate deformation mechanisms remains a key challenge in current research.Neutron diffraction(ND)techniques offer distinct advantages over traditional microscopic methods for characterizing such complex deformation behavior.The strong penetration capability of neutrons enables in-situ,real-time,and non-destructive detection of structural evolution in most centimeter-level bulk samples under complex environments,and ND allows precise characterization of lattice site occupations for light elements,such as C and O,and neighboring elements.This review discussed the principles of ND,experiment procedures,and data analysis.Combining with recent advances in the research about face-centered cubic high-entropy alloy,typical examples of using ND to investigate the deformation behavior were summarized,ultimately revealing deformation mechanisms dominated by dislocations,stacking faults,twinning,and phase transformations.
基金Supported by National Key R&D Program of China(2022YFA1503400)。
文摘Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prepared,and the influence mechanism of additives on the structure-performance relationship of the catalysts was systematically explored.Through a variety of characterization methods such as XRD,N2 physical adsorption-desorption,TEM,H_(2)-TPR,CO_(2)-TPD and XPS,combined with catalytic performance evaluation experiments,the correlation between the microstructure of catalysts and the reaction performance of CO_(2)hydrogenation to methanol was analyzed in depth.The results show that metal additives significantly improve the performance of catalysts.After the introduction of additives,the specific surface area and pore volume of the catalysts increase,the grain size of Cu decreases,and its dispersion improves.The Ce-modified CZC catalyst exhibited the best performance,with the grain size of CuO as small as 11.41 nm,and the surface oxygen vacancy concentration(OⅡ/OⅠ=3.15)was significantly higher than that of other samples.The reaction performance test shows that under the conditions of 2.8 MPa,8000 h−1 and 280℃,the CO_(2)conversion of the CZC catalyst reached 18.83%,the methanol selectivity was 68.40%,and the methanol yield was 12.88%,all of which are superior to other catalysts.Its excellent performance can be attributed to the fact that CeO_(2)enhances the metal-support interaction,increases the surface basicity,promotes the adsorption and activation of CO_(2),and simultaneously inhibits the reverse water-gas shift side reaction.This study clarifies the structure-activity regulation mechanism of additive modification on Cu-ZnO catalysts,providing a theoretical basis and technical reference for the development of efficient catalysts for CO_(2)hydrogenation to methanol.
基金Supported by the National Natural Science Foundation of China(52506188,52476215)Natural Science Foundation of Liaoning Province(2024-MS-139,2024JH3/10200047)Scientific Research Program of Department of Education of Liaoning Province(310125042,LJ212410143033)。
文摘In this paper,the Ni/Al_(2)O_(3) monolithic catalyst with 15%Ni content was prepared using cordierite as a matrix,and the catalyst was modified with 10%NaOH to study the methanation performance of biomass gasification simulated gas based on alkali-modified Ni/Al_(2)O_(3) monolithic catalyst.BET,TEM,H_(2)-TPR,XRD,CO_(2)-TPD and TG were used to characterize the physicochemical properties of the catalyst before and after modification.The results indicated that the CO conversion rate trends of unmodified and modified Ni/Al_(2)O_(3) monolithic catalysts over 2 h were fundamentally consistent.However,the Ni/Al_(2)O_(3) catalysts modified for 2 h demonstrated significantly enhanced performance compared to those modified for 1 h.Regarding CH4 selectivity,the modified Ni/Al_(2)O_(3) catalyst exhibited markedly better performance than the unmodified Ni/Al_(2)O_(3) catalyst,confirming the enhanced methane performance of the alkali-modified Ni/Al_(2)O_(3) monolithic catalyst.Under optimized conditions(H_(2)/CO volume ratio of 3∶1,space velocity of 10000 mL/(g·h),and temperature of 400℃),the methanation performance of the Ni/Al_(2)O_(3) monolithic catalyst modified for 2 h reached its peak,achieving a CO conversion rate of 97%with 100%CH4 selectivity.
基金Supported by Innovation Capability Support Program of Shaanxi(2024RS-CXTD-53,2024ZC-KJXX-096)the Key R&D Program of Shaanxi Province(2022QCY-LL-69)Xi’an Science and Technology Project(24GXFW0089)。
文摘Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting two greenhouse gases(methane and carbon dioxide)into syngas and its promising industrial applications.Nickel(Ni)-based catalysts,with high catalytic activity,low cost,and abundant resources,are considered ideal candidates for industrial applications.In this article,three reaction kinetic models were briefly introduced,namely the Power-Law(PL)model,the Eley-Rideal(ER)model,and the Langmuir-Hinshelwood-Hougen-Watson(LHHW)model.Based on the LHHW model,the reaction kinetics and mechanisms of different catalytic systems were systematically discussed,including the properties of supports,the doping of noble metals and transition metals,the role of promoters,and the influence of the geometric and electronic structures of Ni on the reaction mechanism.Furthermore,the kinetics of carbon deposition and elimination on various catalysts were analyzed.Based on the reaction rate expressions for carbon elimination,the reasons for the high activity of transition metal iron(Fe)-doped catalysts and core-shell structured catalysts in carbon elimination were explained.Based on the detailed collation and comparative analysis of the reaction mechanisms and kinetic characteristics across diverse Ni-based catalytic systems,a theoretical guidance for the designing of high-performance catalysts was provided in this work.
基金Supported by the National Natural Science Foundation of China(No.52273056)the Science and Technology Development Program of Jilin Province,China(No.YDZJ202501ZYTS305)。
文摘Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen evolution reaction(HER)and the anodic oxygen evolution reaction(OER).Transition metal-based catalysts have garnered significant research interest as promising alternatives to noble-metal catalysts,owing to their low cost,tunable composition,and noble-metal-like catalytic activity.Nevertheless,systematic reviews on their application as bifunctional catalysts for overall water splitting(OWS)are still limited.This review comprehensively outlines the principal categories of bifunctional transition metal electrocatalysts derived from electrospun nanofibers(NFs),including metals,oxides,phosphides,sulfides,and carbides.Key strategies for enhancing their catalytic performance are systematically summarized,such as heterointerface engineering,heteroatom doping,metal-nonmetal-metal bridging architectures,and single-atom site design.Finally,current challenges and future research directions are discussed,aiming to provide insightful perspectives for the rational design of high-performance electrocatalysts for OWS.
基金Supported by the National Key Research and Development Program of China(2022YFB4101800)the National Natural Science Foundation of China(22172032,U22A20431)。
文摘CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the catalytic mechanism of Cu species in the CZA catalyst remains a great challenge.In this study,we systematically investigated the valence state change of active Cu species in CZA catalyst and their influence on catalytic performance by modifying the catalysts with varying amounts of electron donor K,thus identifying the catalytic function of Cu species with different valence states.H2-TPR,XPS and HR-TEM characterizations reveal that the highly dispersed K species supported on CZA catalysts will inhibit the reduction of CuO,resulting in a small amount of Cu_(2)O active species being produced under reaction conditions thus causing a decrease in catalytic activity.Furthermore,XRD and Cu LMM spectra show that the proportion of Cu^(0) in K-modified CZA catalysts increases with K loading,but a higher proportion of Cu^(0) species on the surface obviously promotes the reverse water gas shift(RWGS)reaction.According to the results of in situ infrared spectroscopy,CZA catalyst follows the reaction pathway mediated by HCOO^(*)in the hydrogenation of CO_(2) to methanol.
基金financial support from the National Natural Science Foundation of China(Nos.22401274,U23B6011)the Jilin Provincial Science and Technology Department Program(No.20250102070JC)。
文摘Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.
基金Supported by the National Key Research and Development Program of China(2023YFB4104500,2023YFB4104502)the National Natural Science Foundation of China(22138013)the Taishan Scholar Project(ts201712020).
文摘Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
基金funded by the Innovative Research Group Project of the National Natural Science Foundation of China(52121004)the Research Development Fund(No.RDF-21-02-060)by Xi’an Jiaotong-Liverpool University+1 种基金support received from the Suzhou Industrial Park High Quality Innovation Platform of Functional Molecular Materials and Devices(YZCXPT2023105)the XJTLU Advanced Materials Research Center(AMRC).
文摘Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction(ORR)and chlorideinduced degradation over conventional catalysts.In this study,we proposed a universal synthetic strategy to construct heteroatom axially coordinated Fe–N_(4) single-atom seawater catalyst materials(Cl–Fe–N_(4) and S–Fe–N_(4)).X-ray absorption spectroscopy confirmed their five-coordinated square pyramidal structure.Systematic evaluation of catalytic activities revealed that compared with S–Fe–N_(4),Cl–Fe–N_(4) exhibits smaller electrochemical active surface area and specific surface area,yet demonstrates higher limiting current density(5.8 mA cm^(−2)).The assembled zinc-air batteries using Cl–Fe–N_(4) showed superior power density(187.7 mW cm^(−2) at 245.1 mA cm^(−2)),indicating that Cl axial coordination more effectively enhances the intrinsic ORR activity.Moreover,Cl–Fe–N_(4) demonstrates stronger Cl−poisoning resistance in seawater environments.Chronoamperometry tests and zinc-air battery cycling performance evaluations confirmed its enhanced stability.Density functional theory calculations revealed that the introduction of heteroatoms in the axial direction regulates the electron center of Fe single atom,leading to more active reaction intermediates and increased electron density of Fe single sites,thereby enhancing the reduction in adsorbed intermediates and hence the overall ORR catalytic activity.
