With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Ni...With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Nickel-based catalysts are renowned for their outstanding activity and selectivity in this process.The impact of metal-support interaction(MSI),on Ni-based catalyst performance has been extensively researched and debated recently.This paper reviews the recent research progress of MSI on Ni-based catalysts and their characterization and modulation strategies in catalytic reactions.From the perspective of MSI,the effects of different carriers(metal oxides,carbon materials and molecular sieves,etc.)are introduced on the dispersion and surface structure of Ni active metal particles,and the effect of MSI on the activity and stability of DRM reactions on Ni-based catalysts is discussed in detail.Future research should focus on better understanding and controlling MSI to improve the performance and durability of nickel-based catalysts in CH_(4)-CO_(2)reforming,advancing cleaner energy technologies.展开更多
Recent research progress on the use of Ni-based catalysts supported by various carbon materials,such as carbon nanotubes,graphene,and activated carbon,for the hydrogenation of CO_(2)to CH_(4)is summarized.The influenc...Recent research progress on the use of Ni-based catalysts supported by various carbon materials,such as carbon nanotubes,graphene,and activated carbon,for the hydrogenation of CO_(2)to CH_(4)is summarized.The influence of additives and surface modification methods on improving their catalytic performance is discussed as is the reaction mechanism,especially the structurefunction relationship produced by the carbon.The review provides a comprehensive directory for the rational design of carbon-supported Ni-based catalysts for the methanation of CO_(2).展开更多
Ni-based materials,widely recognized for their exceptional catalytic properties,experience structural transformations that profoundly influence their performance characteristics and operational stability.To deeply und...Ni-based materials,widely recognized for their exceptional catalytic properties,experience structural transformations that profoundly influence their performance characteristics and operational stability.To deeply understand the reconstruction mechanism of Ni-based catalysts,this review systematically summarizes the advanced strategies tailoring the dynamic reconstruction process,including electrochemical activation,defect engineering,partial etching,ionic doping,and heterostructure construction.Furthermore,we discuss the implications of these surface transformations on catalytic activity,highlighting their role in optimizing reaction pathways and enhancing overall efficiency in various electrooxidation reactions,such as oxygen evolution reaction(OER),urea oxidation reaction(UOR),glycerol oxidation reaction(GOR),hydroxymethylfurfural oxidation reaction(HMFOR),and ammonia oxidation reaction(AOR).By summarizing recent research findings,this review aims to provide a systematical summary of how surface dynamics can be harnessed to improve the design of Ni-based catalysts for a variety of electrooxidation applications,paving the way for advancements in energy conversion and storage technologies.展开更多
Photothermal catalytic methane dry reforming(DRM)technology can convert greenhouse gases(i.e.CH_(4)and CO_(2))into syngas(i.e.H_(2)and CO),providing more opportunities for reducing the greenhouse effect and achieving ...Photothermal catalytic methane dry reforming(DRM)technology can convert greenhouse gases(i.e.CH_(4)and CO_(2))into syngas(i.e.H_(2)and CO),providing more opportunities for reducing the greenhouse effect and achieving carbon neutrality.In the DRM field,Ni-based catalysts attract wide attention due to their low cost and high activity.However,the carbon deposition over Ni-based catalysts always leads to rapid deactivation,which is still a main challenge.To improve the long-term stability of Ni-based catalysts,this work proposes a carbon-atom-diffusion strategy under photothermal conditions and investigates its effect on a Zn-doped Ni-based photothermal catalyst(Ni_(3)Zn@CeO_(2)).The photothermal catalytic behavior of Ni_(3)Zn@CeO_(2)can maintain more than 70 h in DRM reaction.And the photocatalytic DRM activity of Ni_(3)Zn@CeO_(2)is 1.2 times higher than thermal catalytic activity.Density functional theory(DFT)calculation and experimental characterizations indicate that Ni_(3)Zn promotes the diffusion of carbon atoms into the Ni_(3)Zn to form the Ni_(3)ZnC0.7 phase with body-centered cubic(bcc)structure,thus inhibiting carbon deposition.Further,in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy and DFT calculation prove Ni_(3)Zn@CeO_(2)benefits the CH_(4)activation and inhibits the carbon deposition during the DRM process.Through inducing carbon atoms diffusion within the Ni_(3)Zn lattice,this work provides a straightforward and feasible strategy for achieving efficient photothermal catalytic DRM and even other CH_(4)conversion implementations with long-term stability.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
The unique crystallographic lamellar microstructure(CLM) Ni-based superalloys fabricated by laser powder bed fusion(LPBF) exhibits excellent tensile properties.This study aims to investigate CLM's high-temperature...The unique crystallographic lamellar microstructure(CLM) Ni-based superalloys fabricated by laser powder bed fusion(LPBF) exhibits excellent tensile properties.This study aims to investigate CLM's high-temperature stress rupture behavior and use these findings to improve the additive manufacturing process.The result shows that the high temperature-induced intergranular fracture in <110> grain region is responsible for stress rupture failure under both conditions of 760 ℃/780 MPa and 980 ℃/260 MPa.Among them,the sub-grain boundary fracture occurs only under high temperature and low stress,980 ℃/260 MPa.Due to the severe intergranular fracture induced by stray grains,the stress rupture life is very low under both conditions.According to the finite element simulation,the formation of stray grains stems from the unstable heat flow within the melt pool during the process.In addition,the shorter stress rupture lifetime does not excite a more pronounced dislocation network around the γ′ phase.However,the deformation twins can still be activated inside the <110> grains,so it has excellent plasticity under both test conditions.Finally,this work indicates that the future optimization of CLM by LPBF should focus on eliminating of high-angle grain boundaries in <110> grains.展开更多
The oxygen evolution reaction(OER)suffers from sluggish kinetics,necessitating efficient electrocatalysts to reduce overpotentials in water splitting.Currently recognized OER mechanisms primarily include the adsorbate...The oxygen evolution reaction(OER)suffers from sluggish kinetics,necessitating efficient electrocatalysts to reduce overpotentials in water splitting.Currently recognized OER mechanisms primarily include the adsorbate evolution mechanism(AEM),lattice oxygen mechanism(LOM),and oxide path mechanism(OPM).Compared to AEM,limited by scaling relationships,and LOM,constrained by stability issues,the OPM offers a promising alternative by enabling direct O-O bond formation via dual active sites,thus bypassing^(*)OOH intermediates and lattice O involvement and achieving a balance between activity and durability.However,activating the OPM process requires precise control over the spatial and electronic structure of active sites,making the design of OPM-based catalysts challenging.While previous reviews have focused on homo/heteronuclear diatomic perspectives of OPM-based catalysts,it is urgent to systematically summarize design strategies to provide a rational reference for their development.Herein,a review of design strategies for OPM-based OER catalysts across three scales is comprehensively presented,including in-situ engineering,doping-enabled sites reconstruction,and introducing new sites for nanoparticles,direct synthesis or post-treatments for molecular catalysts,and doping or template strategies for atom pairs or arrays.The unique advantage of atom arrays is also highlighted,and their future research directions and possible strategies are discussed.This review provides a systematic summary and forward-looking perspectives for rationally designing high-performance OPM-based OER catalysts.展开更多
Turbine blades,due to their intricate geometry,are exposed to multiaxial stresses during operation.Consequently,it is imperative to examine the anisotropy of their stress-rupture behavior across various testing scenar...Turbine blades,due to their intricate geometry,are exposed to multiaxial stresses during operation.Consequently,it is imperative to examine the anisotropy of their stress-rupture behavior across various testing scenarios,particularly under high-temperature conditions.Stress-rupture behavior of a Ni-based single crystal superalloy was investigated under a load varying from 100 MPa to 137 MPa at 1,100℃ for both[001]-and[111]-orientated specimens.Results demonstrate that the rupture behavior of[111]-orientated specimens exhibits obviously higher sensitive to applied stress compared to[001]-orientated specimens.This difference is primarily attributed to the orientation dependentγ'coarsening behavior and distinct dislocation interactions atγ/γ'interfaces.In[001]-oriented specimens,plate-likeγ/γ'rafts rapidly form alongside well-developed interfacial dislocation networks,where theγ/γ'misfit stress dominates the microstructural evolution.In contrast,the[111]-orientated specimens exhibit retained,coarsenedγ'precipitates embedded within theγmatrix,accompanied by poorly developed interfacial dislocation networks.展开更多
Under the context of global energy transition and carbon neutrality,controlling nitrogen oxide(NO_(x))emissions from biomass combustion is of great significance,and the development of high-efficiency low-temperature c...Under the context of global energy transition and carbon neutrality,controlling nitrogen oxide(NO_(x))emissions from biomass combustion is of great significance,and the development of high-efficiency low-temperature catalysts has become a current research focus.In this study,Nb was used to dope and modify the Mn_(7)-Cu_(3)/BCN catalyst to construct the Mn_(7)-Cu_(3)-Nb_(x)/BCN system.The doping amount was optimized through selective catalytic reduction(SCR)activity tests.The reaction mechanism was explored by combining in situ DRIFTS and density functional theory(DFT)simulations.Experimental findings revealed that the catalyst doped with 0.05%Nb achieved the optimal performance,sustaining a NO conversion efficiency of≥94%within the temperature window of 150−275℃while demonstrating improved resistance to alkali metal K poisoning.Mechanistic analyses showed that at low temperatures,the catalyst facilitated the SCR reaction via both the Eley-Rideal(E-R)and Langmuir-Hinshelwood(L-H)pathways,with the synergistic interaction between multiple active sites driving the efficient conversion of NH3 and NO.DFT calculations further confirmed that both pathways had the characteristics of low reaction energy barriers and significant exothermicity,ensuring the high activity and feasibility of the low-temperature reaction.The findings provided foundational theoretical support for the design of Nb-doped Mn-Cu-supported catalysts and the exploration of the underlying working mechanisms.展开更多
Practical application of lithium-sulfur(Li-S)batteries is hindered by the migration of lithium polysulfides(LiPSs),sluggish conversion kinetics,and anode instability.In these regards,with a novel strategy focusing on ...Practical application of lithium-sulfur(Li-S)batteries is hindered by the migration of lithium polysulfides(LiPSs),sluggish conversion kinetics,and anode instability.In these regards,with a novel strategy focusing on the selective elevation of d-orbitals,Mn/Fe dual-atom catalysts(MnFe DACs)embedded in Ndoped carbon frameworks are designed.Theoretical calculations reveal that energy levels of d_(z2),d_(zx),and d_(yz)orbitals participating in d-p hybridization are elevated closer to the Fermi level at both Mn and Fe sites,thereby reducing orbital occupancy in antibonding states.Consequently,these electronic features via the selective d-orbital elevation enable enhanced adsorption strength toward intermediate LiPSs and accelerate redox reaction during cell operation.Also,the MnFe DAC improves anode stability by regulating Li-ion flux with its lithiophilic active sites.Specifically,the cell equipped with MnFe DAC-modified separator maintains a capacity of 758.4 mAh g^(-1)after 400 cycles at 0.5 C.Notably,the cell demonstrates a high initial capacity of 822.7 mAh g^(-1)with only 0.047%decay rate over 1000 cycles at 1 C.Even under high sulfur-loading(5.0 mg cm^(-2))and low electrolyte-to-sulfur(E/S)ratio(6μL mg^(-1)),a high initial areal capacity of 4.94 m Ah cm^(-2)with 92.5%retention after 50 cycles at 0.1 C is achieved.This study provides guidelines on selective modulation of d-orbitals in DACs for high-performance Li-S batteries.展开更多
Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the effica...Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.展开更多
The production of liquid fuels from syngas can help alleviate energy supply challenges,support carbon neutrality,and address climate change.However,this process involves considerable complexity due to the interplay of...The production of liquid fuels from syngas can help alleviate energy supply challenges,support carbon neutrality,and address climate change.However,this process involves considerable complexity due to the interplay of multiple influencing factors,including feedstock characteristics,catalyst properties,and reaction conditions.To facilitate process optimization,we developed a machine learning model to predict CO conversion and C_(5+)selectivity based on key input descriptors,A dataset of 236 entries was compiled from existing literature,enabling data mining to identify the importance of reaction temperature,reduction degree,and cobalt loading.Analysis revealed that higher C_(5+)selectivity is achieved at lower temperatures(<240℃)and moderate cobalt loading(~20%).Additionally,it was found that excessively small cobalt particles(<6 nm)negatively impact C_(5+)selectivity due to increased methane formation and decreased active sites stability at the nanoscale.The proposed framework is entirely data-driven and interpretable,incorporating Permutation Importance(PI),Shapley Additive Explanations(SHAP),and Partial Dependence Plot(PDP),a game theory-based interpretation approach to isolate and analyze the effects of individual and paired descriptors,thereby offering valuable theoretical insights for guiding experimental research.展开更多
基金supported by the Natural Science Foundation of Shanxi Province(202203021221155)the Foundation of National Key Laboratory of High Efficiency and Low Carbon Utilization of Coal(J23-24-902)。
文摘With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Nickel-based catalysts are renowned for their outstanding activity and selectivity in this process.The impact of metal-support interaction(MSI),on Ni-based catalyst performance has been extensively researched and debated recently.This paper reviews the recent research progress of MSI on Ni-based catalysts and their characterization and modulation strategies in catalytic reactions.From the perspective of MSI,the effects of different carriers(metal oxides,carbon materials and molecular sieves,etc.)are introduced on the dispersion and surface structure of Ni active metal particles,and the effect of MSI on the activity and stability of DRM reactions on Ni-based catalysts is discussed in detail.Future research should focus on better understanding and controlling MSI to improve the performance and durability of nickel-based catalysts in CH_(4)-CO_(2)reforming,advancing cleaner energy technologies.
文摘Recent research progress on the use of Ni-based catalysts supported by various carbon materials,such as carbon nanotubes,graphene,and activated carbon,for the hydrogenation of CO_(2)to CH_(4)is summarized.The influence of additives and surface modification methods on improving their catalytic performance is discussed as is the reaction mechanism,especially the structurefunction relationship produced by the carbon.The review provides a comprehensive directory for the rational design of carbon-supported Ni-based catalysts for the methanation of CO_(2).
基金supported by National Natural Science Foundation of China(Nos.52073199 and 52274304)。
文摘Ni-based materials,widely recognized for their exceptional catalytic properties,experience structural transformations that profoundly influence their performance characteristics and operational stability.To deeply understand the reconstruction mechanism of Ni-based catalysts,this review systematically summarizes the advanced strategies tailoring the dynamic reconstruction process,including electrochemical activation,defect engineering,partial etching,ionic doping,and heterostructure construction.Furthermore,we discuss the implications of these surface transformations on catalytic activity,highlighting their role in optimizing reaction pathways and enhancing overall efficiency in various electrooxidation reactions,such as oxygen evolution reaction(OER),urea oxidation reaction(UOR),glycerol oxidation reaction(GOR),hydroxymethylfurfural oxidation reaction(HMFOR),and ammonia oxidation reaction(AOR).By summarizing recent research findings,this review aims to provide a systematical summary of how surface dynamics can be harnessed to improve the design of Ni-based catalysts for a variety of electrooxidation applications,paving the way for advancements in energy conversion and storage technologies.
文摘Photothermal catalytic methane dry reforming(DRM)technology can convert greenhouse gases(i.e.CH_(4)and CO_(2))into syngas(i.e.H_(2)and CO),providing more opportunities for reducing the greenhouse effect and achieving carbon neutrality.In the DRM field,Ni-based catalysts attract wide attention due to their low cost and high activity.However,the carbon deposition over Ni-based catalysts always leads to rapid deactivation,which is still a main challenge.To improve the long-term stability of Ni-based catalysts,this work proposes a carbon-atom-diffusion strategy under photothermal conditions and investigates its effect on a Zn-doped Ni-based photothermal catalyst(Ni_(3)Zn@CeO_(2)).The photothermal catalytic behavior of Ni_(3)Zn@CeO_(2)can maintain more than 70 h in DRM reaction.And the photocatalytic DRM activity of Ni_(3)Zn@CeO_(2)is 1.2 times higher than thermal catalytic activity.Density functional theory(DFT)calculation and experimental characterizations indicate that Ni_(3)Zn promotes the diffusion of carbon atoms into the Ni_(3)Zn to form the Ni_(3)ZnC0.7 phase with body-centered cubic(bcc)structure,thus inhibiting carbon deposition.Further,in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy and DFT calculation prove Ni_(3)Zn@CeO_(2)benefits the CH_(4)activation and inhibits the carbon deposition during the DRM process.Through inducing carbon atoms diffusion within the Ni_(3)Zn lattice,this work provides a straightforward and feasible strategy for achieving efficient photothermal catalytic DRM and even other CH_(4)conversion implementations with long-term stability.
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.
基金the financial support by the Project of Taihang Laboratory (No. A3023)Science Center for Gas Turbine Project (Grant No. P2022-CIV-002-001)。
文摘The unique crystallographic lamellar microstructure(CLM) Ni-based superalloys fabricated by laser powder bed fusion(LPBF) exhibits excellent tensile properties.This study aims to investigate CLM's high-temperature stress rupture behavior and use these findings to improve the additive manufacturing process.The result shows that the high temperature-induced intergranular fracture in <110> grain region is responsible for stress rupture failure under both conditions of 760 ℃/780 MPa and 980 ℃/260 MPa.Among them,the sub-grain boundary fracture occurs only under high temperature and low stress,980 ℃/260 MPa.Due to the severe intergranular fracture induced by stray grains,the stress rupture life is very low under both conditions.According to the finite element simulation,the formation of stray grains stems from the unstable heat flow within the melt pool during the process.In addition,the shorter stress rupture lifetime does not excite a more pronounced dislocation network around the γ′ phase.However,the deformation twins can still be activated inside the <110> grains,so it has excellent plasticity under both test conditions.Finally,this work indicates that the future optimization of CLM by LPBF should focus on eliminating of high-angle grain boundaries in <110> grains.
基金funding from the National Natural Science Foundation of China(22378289)the Key Central Government Guides Local Funds for Science and Technology Development(YDZJSX2022A021)the special fund for Science and Technology Innovation Teams of Shanxi Province(202304051001026)。
文摘The oxygen evolution reaction(OER)suffers from sluggish kinetics,necessitating efficient electrocatalysts to reduce overpotentials in water splitting.Currently recognized OER mechanisms primarily include the adsorbate evolution mechanism(AEM),lattice oxygen mechanism(LOM),and oxide path mechanism(OPM).Compared to AEM,limited by scaling relationships,and LOM,constrained by stability issues,the OPM offers a promising alternative by enabling direct O-O bond formation via dual active sites,thus bypassing^(*)OOH intermediates and lattice O involvement and achieving a balance between activity and durability.However,activating the OPM process requires precise control over the spatial and electronic structure of active sites,making the design of OPM-based catalysts challenging.While previous reviews have focused on homo/heteronuclear diatomic perspectives of OPM-based catalysts,it is urgent to systematically summarize design strategies to provide a rational reference for their development.Herein,a review of design strategies for OPM-based OER catalysts across three scales is comprehensively presented,including in-situ engineering,doping-enabled sites reconstruction,and introducing new sites for nanoparticles,direct synthesis or post-treatments for molecular catalysts,and doping or template strategies for atom pairs or arrays.The unique advantage of atom arrays is also highlighted,and their future research directions and possible strategies are discussed.This review provides a systematic summary and forward-looking perspectives for rationally designing high-performance OPM-based OER catalysts.
基金financially supported by the National Science and Technology Major Project of China(No.2019-VII-0019-0161 and No.2019-VII-0004-0144)the National Natural Science Foundation of China(No.92360302)the Shandong Provincial Natural Science Foundation of China(No.ZR2021QE103)。
文摘Turbine blades,due to their intricate geometry,are exposed to multiaxial stresses during operation.Consequently,it is imperative to examine the anisotropy of their stress-rupture behavior across various testing scenarios,particularly under high-temperature conditions.Stress-rupture behavior of a Ni-based single crystal superalloy was investigated under a load varying from 100 MPa to 137 MPa at 1,100℃ for both[001]-and[111]-orientated specimens.Results demonstrate that the rupture behavior of[111]-orientated specimens exhibits obviously higher sensitive to applied stress compared to[001]-orientated specimens.This difference is primarily attributed to the orientation dependentγ'coarsening behavior and distinct dislocation interactions atγ/γ'interfaces.In[001]-oriented specimens,plate-likeγ/γ'rafts rapidly form alongside well-developed interfacial dislocation networks,where theγ/γ'misfit stress dominates the microstructural evolution.In contrast,the[111]-orientated specimens exhibit retained,coarsenedγ'precipitates embedded within theγmatrix,accompanied by poorly developed interfacial dislocation networks.
基金Supported by National Key Research and Development Program of China(2020YFD1100302)。
文摘Under the context of global energy transition and carbon neutrality,controlling nitrogen oxide(NO_(x))emissions from biomass combustion is of great significance,and the development of high-efficiency low-temperature catalysts has become a current research focus.In this study,Nb was used to dope and modify the Mn_(7)-Cu_(3)/BCN catalyst to construct the Mn_(7)-Cu_(3)-Nb_(x)/BCN system.The doping amount was optimized through selective catalytic reduction(SCR)activity tests.The reaction mechanism was explored by combining in situ DRIFTS and density functional theory(DFT)simulations.Experimental findings revealed that the catalyst doped with 0.05%Nb achieved the optimal performance,sustaining a NO conversion efficiency of≥94%within the temperature window of 150−275℃while demonstrating improved resistance to alkali metal K poisoning.Mechanistic analyses showed that at low temperatures,the catalyst facilitated the SCR reaction via both the Eley-Rideal(E-R)and Langmuir-Hinshelwood(L-H)pathways,with the synergistic interaction between multiple active sites driving the efficient conversion of NH3 and NO.DFT calculations further confirmed that both pathways had the characteristics of low reaction energy barriers and significant exothermicity,ensuring the high activity and feasibility of the low-temperature reaction.The findings provided foundational theoretical support for the design of Nb-doped Mn-Cu-supported catalysts and the exploration of the underlying working mechanisms.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2024-00355916)by the NRF grant funded by the Korea government(MSIT)(RS-2021-NR060090)by the Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(RS-2024-00419413,HRD Program for Industrial Innovation)。
文摘Practical application of lithium-sulfur(Li-S)batteries is hindered by the migration of lithium polysulfides(LiPSs),sluggish conversion kinetics,and anode instability.In these regards,with a novel strategy focusing on the selective elevation of d-orbitals,Mn/Fe dual-atom catalysts(MnFe DACs)embedded in Ndoped carbon frameworks are designed.Theoretical calculations reveal that energy levels of d_(z2),d_(zx),and d_(yz)orbitals participating in d-p hybridization are elevated closer to the Fermi level at both Mn and Fe sites,thereby reducing orbital occupancy in antibonding states.Consequently,these electronic features via the selective d-orbital elevation enable enhanced adsorption strength toward intermediate LiPSs and accelerate redox reaction during cell operation.Also,the MnFe DAC improves anode stability by regulating Li-ion flux with its lithiophilic active sites.Specifically,the cell equipped with MnFe DAC-modified separator maintains a capacity of 758.4 mAh g^(-1)after 400 cycles at 0.5 C.Notably,the cell demonstrates a high initial capacity of 822.7 mAh g^(-1)with only 0.047%decay rate over 1000 cycles at 1 C.Even under high sulfur-loading(5.0 mg cm^(-2))and low electrolyte-to-sulfur(E/S)ratio(6μL mg^(-1)),a high initial areal capacity of 4.94 m Ah cm^(-2)with 92.5%retention after 50 cycles at 0.1 C is achieved.This study provides guidelines on selective modulation of d-orbitals in DACs for high-performance Li-S batteries.
基金supported by the National Key R&D Program of China (2021YFA1502802)the National Natural Science Foundation of China (U21B2092, 22202213, 22402210, 22502215, 22502214, 22572200, and 22579171)+3 种基金the International Partnership Program of Chinese Academy of Sciences (172GJHZ2022028MI)the Shenyang Bureau of Science and Technology (24-213-3-25)the Natural Science Foundation of Liaoning Province (2025BS0153)Zhongke Technology Achievement Transfer and Transformation Center of Henan Province 2025119
文摘Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.
基金financially supported by the JSPS Fund(23H05404,22H01864,and 20K05219)provided by the National Natural Science Foundation of China(22178369)+1 种基金the National Key R&D Program of China(2023YFB4104501)the Liaoning Binhai Laboratory(LBLG2024-08)。
文摘The production of liquid fuels from syngas can help alleviate energy supply challenges,support carbon neutrality,and address climate change.However,this process involves considerable complexity due to the interplay of multiple influencing factors,including feedstock characteristics,catalyst properties,and reaction conditions.To facilitate process optimization,we developed a machine learning model to predict CO conversion and C_(5+)selectivity based on key input descriptors,A dataset of 236 entries was compiled from existing literature,enabling data mining to identify the importance of reaction temperature,reduction degree,and cobalt loading.Analysis revealed that higher C_(5+)selectivity is achieved at lower temperatures(<240℃)and moderate cobalt loading(~20%).Additionally,it was found that excessively small cobalt particles(<6 nm)negatively impact C_(5+)selectivity due to increased methane formation and decreased active sites stability at the nanoscale.The proposed framework is entirely data-driven and interpretable,incorporating Permutation Importance(PI),Shapley Additive Explanations(SHAP),and Partial Dependence Plot(PDP),a game theory-based interpretation approach to isolate and analyze the effects of individual and paired descriptors,thereby offering valuable theoretical insights for guiding experimental research.
