An advanced AlCrSiN/AlCrN/CrN/Cr multilayer coating was developed via hybrid multiarc ion plating and high-power impulse magnetron sputtering.The multilayer design enhanced the substrate-coating compatibility,achievin...An advanced AlCrSiN/AlCrN/CrN/Cr multilayer coating was developed via hybrid multiarc ion plating and high-power impulse magnetron sputtering.The multilayer design enhanced the substrate-coating compatibility,achieving a critical load of 87.8 N.Silicon doping induced nanocrystallization and amorphization,increasing the hardness to 26 GPa.At high temperatures,a nanoscale Cr-rich(Cr,Al)_(2)O_(3) layer was formed,effectively inhibiting oxygen diffusion.The coating underwent unique phase transformations,during which Cr_(2)N and amorphous Si3N4 were converted into dispersed SiCr_(3) nanoparticles,which stabilized Cr atoms and suppressed their outward diffusion.Ab initio molecular dynamics simulations revealed that Cr atoms exhibited higher chemical activity and oxygen-capture capability than Al atoms and Si atoms served as diffusion barriers by pinning onto the oxidized surface,considerably improving the oxidation resistance of the coating.展开更多
Al_(2)O_(3)scale-forming materials are highly desirable for high-temperature oxidation resistance,and the for-mation of α-Al_(2)O_(3)scales with low-angle grain boundaries(LAGBs)will increase their service lifetime.H...Al_(2)O_(3)scale-forming materials are highly desirable for high-temperature oxidation resistance,and the for-mation of α-Al_(2)O_(3)scales with low-angle grain boundaries(LAGBs)will increase their service lifetime.However,the synthesis of LAGBs is a considerable challenge.Herein,a novel methodology for engineering in situ α-Al_(2)O_(3)with LAGBs is designed,capitalizing on preferential nucleation.This approach employs a dual-stage preoxidation process,initiating with the selective nucleation of α-Al_(2)O_(3)under extremely low oxygen partial pressures,followed by the growth of these nuclei into a dense,protective oxide layer un-der marginally higher oxygen partial pressures.Based on this method,an α-Al_(2)O_(3)film with LAGBs is finally obtained,which significantly improves the oxidation resistance.This study not only paves the way for advanced materials to improve durability in high-temperature environments but also provides novel insight into the mechanisms of α-Al_(2)O_(3)film formation and growth under controlled oxidative conditions.展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
About 70%of the flue gas in the iron-steel industry has achieved multi-pollutant ultra-low emissions in China until 2023,and then the blast furnace gas purification has become the control step and bottleneck.Our resea...About 70%of the flue gas in the iron-steel industry has achieved multi-pollutant ultra-low emissions in China until 2023,and then the blast furnace gas purification has become the control step and bottleneck.Our research group has designed and constructed the world’s first blast furnace gas desulfurization pilot plant with the scale of 2000 Nm^(3)/h in October 2021.The pilot plant is a two-step combined desulfurization device including catalytic hydrolysis of carbonyl sulfur(COS)and absorption-oxidation of H_(2)S,continuously running for 120 days.In the hydrolysis system,one reason for catalyst deactivation has been verified from the sulfur deposition.HCN in blast furnace gas can be hydrolyzed on the hydrolysis catalyst to produce the nitrogen deposition,which is one of the reasons for catalyst deactivation and has never been found in previous studies.The deposition forms of S and N elements are determined,S element forms elemental sulfur and sulfate,while N element forms-NH_(2)and NH_(4)^(+).In the absorption-oxidation system,the O_(2)loading and the residence time have been optimized to control the oxidation of HS^(−)to produce elemental sulfur instead of by-product S_(2)O_(3)^(2−).The balance and distribution of S and N elements have been calculated for thewholemulti-phase system,approximately 84.4%of the sulfur is converted to solid sulfur product,about 1.3%of the sulfur and 19.2%of N element are deposited on the hydrolysis catalyst.The pilot plant provides technical support formulti-pollutant control of blast furnace.展开更多
Arbitration is a key non-litigation commercial mechanism for the resolution of disputes, and the quality and credibility of its awards depend largely on the competency of the arbitrators. However, the selection and ev...Arbitration is a key non-litigation commercial mechanism for the resolution of disputes, and the quality and credibility of its awards depend largely on the competency of the arbitrators. However, the selection and evaluation systems for arbitrators in China have long faced challenges such as the vague criteria for competency and an unclear professionalization path for arbitrators. To address these issues, this study is grounded in the context of actual Chinese arbitration practice and based on the competency iceberg model. Through a methodological approach encompassing literature reviews, behavioral event interviews, expert revisions, and questionnaire surveys, a Chinese Arbitrator Competency Scale was developed and validated in this study. Examination of the findings indicated that the scale needed to consist of five dimensions—communication and coordination, cognitive skills, ethical conduct, work motivation, and personality traits—and possess a total of 28 specific indicators. Confirmatory analysis of the factors demonstrates a good fit for the five-dimensional model, with each of the dimensions exhibiting high reliability and validity. This scale is innovative in integrating the competency elements with Chinese characteristics, such as commercial acumen, crosscultural mediation skills, and adaptability to the local rule of law. This research not only enriches the competency theory in regard to the field of human resource management but also provides a scientific framework of standards and measurement tools for the selection, training, and evaluation of arbitrators. It thus has significant practical value for enhancing the professionalism and international competitiveness of China's arbitration system.展开更多
The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical pr...The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
Data center industries have been facing huge energy challenges due to escalating power consumption and associated carbon emissions.In the context of carbon neutrality,the integration of data centers with renewable ene...Data center industries have been facing huge energy challenges due to escalating power consumption and associated carbon emissions.In the context of carbon neutrality,the integration of data centers with renewable energy has become a prevailing trend.To advance the renewable energy integration in data centers,it is imperative to thoroughly explore the data centers’operational flexibility.Computing workloads and refrigeration systems are recognized as two promising flexible resources for power regulationwithin data centermicro-grids.This paper identifies and categorizes delay-tolerant computing workloads into three types(long-running non-interruptible,long-running interruptible,and short-running)and develops mathematical time-shifting models for each.Additionally,this paper examines the thermal dynamics of the computer room and derives a time-varying temperature model coupled to refrigeration power.Building on these models,this paper proposes a two-stage,multi-time scale optimization scheduling framework that jointly coordinates computing workloads time-shift in day-ahead scheduling and refrigeration power control in intra-day dispatch to mitigate renewable variability.A case study demonstrates that the framework effectively enhances the renewable-energy utilization,improves the operational economy of the data center microgrid,and mitigates the impact of renewable power uncertainty.The results highlight the potential of coordinated computing workloads and thermal system flexibility to support greener,more cost-effective data center operation.展开更多
The spatial optimization of best management practices(BMPs) plays a critical role in precise watershed pollution control. However, the effectiveness of BMPs exhibits a complex nonlinear dependence on both configuratio...The spatial optimization of best management practices(BMPs) plays a critical role in precise watershed pollution control. However, the effectiveness of BMPs exhibits a complex nonlinear dependence on both configuration unit scale and rainfall intensity, often leading to widespread spatiotemporal mismatches during implementation. To fill this gap, this study proposes a new framework:(a) delineating configuration units based on the implementation scale differences between structural and nonstructural BMPs;(b) incorporating BMP reduction thresholds to enable dynamic adjustment of design scales according to inflow loads;and(c) developing a staged allocation strategy tailored to varying rainfall scenarios. The framework is exemplified by an agricultural catchment in the southeastern Liaohe watershed, China. The results showed that the framework could improve the assessment accuracy and cost-effectiveness of pollution control. Specifically, neglecting BMP reduction thresholds resulted in a 51.35% underestimation of treatment costs. Incorporating these thresholds and dynamically adjusting BMP design scales reduced treatment costs by 62.70%. Furthermore, the framework facilitated more precise localization of structural BMPs(1 km^(2)) and improved optimization efficiency by 95.91%. The proposed staged allocation strategy ensured water quality compliance under varying rainfall intensities. Structural BMPs primarily addressed pollution from light to moderate rainfall in the initial stage, while nonstructural BMPs targeted heavy rainfall pollution in the subsequent stage. The proposed framework may enhance the spatiotemporal adaptability of BMP configuration to respond to the threats posed by climate change and human activities. It can also be extended to other agriculture-dominated watersheds.展开更多
Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,...Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,understanding the oxidation behavior of nuclear graphite is essential for reactor safety.The influence of oxidation involves multiple factors,including temperature,sample size,oxidant,impurities,filler type and size,etc.The size of the filler particles plays a crucial role in this study.Five ultrafine-and superfine-grained nuclear graphite samples(5.9-34.4μm)are manufactured using identical raw materials and manufacturing processes.Isothermal oxidation tests conducted at 650℃-750℃ are used to study the oxidation behavior.Additionally,comprehensive characterization is performed to analyze the crystal structure,surface morphology,and nanoscale to microscale pore structure of the samples.Results indicate that oxidation behavior cannot be predicted solely based on filler grain size.Reactive site concentration,characterized by active surface area,dominates the chemical reaction kinetics,whereas pore tortuosity,quantified by the structural parameterΨ,plays a key role in regulating oxidant diffusion.These findings clarify the dual role of microstructure in oxidation mechanisms and establish a theoretical and experimental basis for the design of high-performance nuclear graphite capable of long-term service in high-temperature gas-cooled reactors.展开更多
Electrocatalytic glucose oxidation to high-value chemicals provides a sustainable route for biomass valorization.NiCo-based catalysts have emerged as promising candidates for glucose oxidation reaction owing to the in...Electrocatalytic glucose oxidation to high-value chemicals provides a sustainable route for biomass valorization.NiCo-based catalysts have emerged as promising candidates for glucose oxidation reaction owing to the intrinsic activity of Ni and Co catalytic centers.However,the dynamic evolution and atomic-scale synergy between these centers remain elusive.Herein,we fabricated NiCo_(2)O_(4)nanosheets supported on nickel foam,where Ni preferentially occupies tetrahedral sites to regulate the electronic configuration of octahedral Co.Experimental and theoretical results demonstrate that the incorporation of tetrahedral Ni induces low-to-intermediate spin transition in octahedral Co,thereby optimizing eg orbital occupancy and stabilizing active sites.This spin-state engineering establishes Ni-Co synergistic catalytic centers for the selective oxidation of glucose to formate(FA).At higher potential(≥1.4 V vs.RHE),octahedral Co undergoes reconstruction into excessive active CoOOH and CoO_(2)species,resulting in glucose overoxidation to CO_(2)and intensified competitive oxygen evolution.In contrast,at lower potentials(<1.4 V vs.RHE),tetrahedral Ni facilitates electron delocalization across the Ni–O–Co lattice,thereby stabilizing octahedral Co for glucose adsorption and oxidation.Subsequently,a coupled electrocatalytic system was constructed,achieving 80.7%FA yield with 91.3%Faradaic efficiency(FE)at NiCo_(2)O_(4)anode and H2 evolution rate of 696μmol h^(−1)with 99.9%FE at Pt cathode for 2 h under 1.35 V vs.RHE.This work provides a deep insight into spin-state regulation of the catalytic center,offering valuable guidance for rational catalyst design.展开更多
Triterpenoids are valuable medicinal scaffolds,characterized by excellent pharmacological properties and the presence of hydroxyl and carboxyl groups that allow for further structural modifications.Expanding the scope...Triterpenoids are valuable medicinal scaffolds,characterized by excellent pharmacological properties and the presence of hydroxyl and carboxyl groups that allow for further structural modifications.Expanding the scope of oxidative modifications on these molecules is crucial for increasing their synthetic structural diversity and unlocking new potential pharmacological activities.However,the progress has been limited by the scarcity of suitable tailoring enzymes.Here,we reported a break-through in achieving targeted and remote dual-site oxidation of licorice triterpenoids using a single P450 mutant.This approach successfully enabled the selective synthesis of the rare triterpenoid,liquiritic acid and 24-OH-liquiritic acid.Our findings demonstrate that microenvironmental accessibility engineering of triterpenoid substrates within the P450 enzyme is essential for continuous and regioselective oxidation.This study not only sheds light on the mechanistic aspects of P450 catalysis but also expands the enzymatic toolkit for selective oxidative modifications in triterpenoid biosynthesis.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 development of efficient photocatalysts for crucial organic transformation,such as aerobic oxidation,remains challenging.Although powdered porous materials offer abundant accessible active sites,their application ...The development of efficient photocatalysts for crucial organic transformation,such as aerobic oxidation,remains challenging.Although powdered porous materials offer abundant accessible active sites,their application in liquid-phase catalysis is often limited by insufficient light absorption and inevitable charge recombination,which are inherent drawbacks of conventional heterogeneous catalysts.Here,through rational design and nanoscale-engineering of porous aromatic frameworks(PAFs)comprising porphyrin and porous organic cage,a quasi-homogeneous porous photocatalyst with high catalytic activity and controllable dimension was developed.The interface-directed growth in oil-in-water emulsion shaped the morphology of photoactive PAFs from powders to nanoflakes,which facilitated the light absorbance and catalyst-substrate interaction.Compared with PAF powders,PAF nanoflakes exhibited superior photocatalytic activity for aerobic oxidation.For mustard gas simulant(2-chloroethyl ethyl sulfide,CEES),PAF nanoflakes exhibited ultrafast detoxification rates in room air with a half-life(t_(1/2))as fast as 26s,which even exceeded other catalysts in pure oxygen.It also completely catalyzed the aerobic oxidation of thioether within 15 min,which is almost the fastest rate among any reported organic photocatalysts.Furthermore,the efficient catalytic performance under mild conditions caused by improved light enrichment,surface charge transfer and carrier lifetime was elucidated.展开更多
Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert...Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert grinding media often fail to discriminate ef-fectively between pyrite and valuable copper minerals due to strong copper activation on pyrite surfaces.This study introduced a novel approach using inorganic radicals generated from peroxymonosulfate(PMS)to selectively oxidize and depress pyrite.Flotation tests with synthetic high-pyrite ore blends showed that PMS significantly reduced pyrite recovery while maintaining or improving chalcopyrite flot-ation.Ethylenediaminetetraacetic acid(EDTA)extraction confirmed selective oxidation of pyrite,and electron paramagnetic resonance(EPR)spectroscopy identified hydroxyl(·OH)and sulfate(SO_(4)^(·-))radicals as the dominant reactive species.Iron ions from grinding me-dia and mineral surfaces were identified as key activators of PMS.A major insight was pyrite’s dual role,acting both as a radical scav-enger and an activator,which made it highly reactive and susceptible to radical-induced oxidation.This process converted surface copper-sulfur species into copper hydroxides,effectively suppressing pyrite flotation.While previous studies have applied EPR to detect radicals in simplified activator/precursor systems,this study provides the first direct mechanistic evidence of radical-driven selectivity in flotation by detecting inorganic radicals in a complex flotation slurry,thereby demonstrating their persistence under industrially relevant conditions and establishing a foundation for more effective and targeted flotation strategies.展开更多
Multi-site coupling is a promising strategy for developing highly efficient and CO-resistant hydrogen oxidation reaction(HOR)catalysts for proton exchange membrane fuel cells(PEMFCs).However,designing multifunctional ...Multi-site coupling is a promising strategy for developing highly efficient and CO-resistant hydrogen oxidation reaction(HOR)catalysts for proton exchange membrane fuel cells(PEMFCs).However,designing multifunctional synergistic schemes for single-atom sites remains a significant challenge.Herein,we propose a dual-template-confined oxophilic engineering strategy to construct well-dispersed iridium-nickel(IrNi)atomic dimers adjacent to IrNi nanoclusters on porous nitrogen-doped carbon(IrNi_(Dimer/NC1.8)-PNC).The paired IrNi dimer features an asymmetric Ir-N_(3)configuration coordinated with heteroatomic Ni-N_(3)O via an N-bridge.Remarkably,IrNi_(Dimer/NC1.8)-PNC exhibits a~23-fold enhancement in mass activity(4.36 A mg-1Ir at 20 mV)and 5-fold longer stability compared to benchmarking Pt/C toward HOR,while achieving a high rated power density of 1.18 W cm^(-2)in PEMFC anode applications.Furthermore,IrNi_(Dimer/NC1.8)-PNC demonstrates superior CO tolerance over monometallic Ir and Pt/C in both half-cell and full-cell devices.Combined experimental and density functional theory studies reveal that oxophilic Ni modulates the electronic environment of Ir through alloying and dimer interactions,thereby enhancing HOR activity.Importantly,the asymmetric IrNi dimer enables efficient CO^(*)and OH^(*)co-adsorption while facilitating CO_(2)^(*)desorption,synergistically mitigating CO poisoning and improving atom utilization efficiency.This work provides a design strategy and fundamental insights for multi-site synergistic catalysts in PEMFC anodes.展开更多
Electrocatalytic oxidation of glycerol for value-added chemicals is a superior strategy to utilize the excess glycerol produced in the biodiesel industry.Pd is one of the few active catalysts for alkaline glycerol oxi...Electrocatalytic oxidation of glycerol for value-added chemicals is a superior strategy to utilize the excess glycerol produced in the biodiesel industry.Pd is one of the few active catalysts for alkaline glycerol oxidation reaction(GOR);however,glycerol inevitably dissociates and converts to carbon dioxide on the Pd surface,which results in its low total Faradaic efficiency(FE)for high-value-added products.Herein,a series of Pd/C and Pd10Bix/C catalysts were synthesized to investigate the GOR pathway.The Pd10Bi3/C catalyst with optimal Bi content achieved an excellent GOR mass activity of 7.5±0.2 A mgPd−1 and an outstanding total FE of 90%±3%,which are much higher than those values on Pd/C(1.2±0.2 A mgPd−1 for mass activity and 63%±4%for total FE).Combined results of in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy and density functional theory calculations show that Bi suppresses the dissociation of glycerol through the“shielding effect”of Bi to the adjacent Pd sites,which weakens the adsorption strength of GOR intermediates on those sites.This work provides a new insight into the GOR mechanism and puts forward a valid strategy for the rational design of catalysts to enable the transformation of glycerol into high-value-added products.展开更多
The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts rem...The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts remains a primary challenge.In this study,an enhancement in catalytic MOR performance is achieved through the incorporation of Mn atoms with unsaturated t_(2g)orbitals into Ni_(3)Se_(4).Comprehensive experimental analyses and theoretical calculations reveal that substituting Ni with Mn induces strong electron-withdrawing effects,effectively modulating the local coordination environment of the metal centers.The presence of Mn also elongates Ni–Se(O)bonds,which reduces eg orbital occupancy and modifies the spin state of the material.Electrochemical measurements demonstrate that electrodes based on this optimized material exhibit a high spin state and deliver excellent catalytic activity,achieving a MOR current density up to∼190 mA cm^(−2)at 1.6 V.This performance enhancement is attributed to the favorable electronic configuration and reduced reaction energy barriers associated with the high-spin state.展开更多
Owing to intensified globalization and informatization,the structures of the urban scale hierarchy and urban networks between cities have become increasingly intertwined,resulting in different spatial effects.Therefor...Owing to intensified globalization and informatization,the structures of the urban scale hierarchy and urban networks between cities have become increasingly intertwined,resulting in different spatial effects.Therefore,this paper analyzes the spatial interaction between urban scale hierarchy and urban networks in China from 2019 to 2023,drawing on Baidu migration data and employing a spatial simultaneous equation model.The results reveal a significant positive spatial correlation between cities with higher hierarchy and those with greater network centrality.Within a static framework,we identify a positive interaction between urban scale hierarchy and urban network centrality,while their spatial cross-effects manifest as negative neighborhood interactions based on geographical distance and positive cross-scale interactions shaped by network connections.Within a dynamic framework,changes in urban scale hierarchy and urban networks are mutually reinforcing,thereby widening disparities within the urban hierarchy.Furthermore,an increase in a city’s network centrality had a dampening effect on the population growth of neighboring cities and network-connected cities.This study enhances understanding of the spatial organisation of urban systems and offers insights for coordinated regional development.展开更多
基金financially supported by the National Science and Technology Major Project(No.2024ZD1404705)。
文摘An advanced AlCrSiN/AlCrN/CrN/Cr multilayer coating was developed via hybrid multiarc ion plating and high-power impulse magnetron sputtering.The multilayer design enhanced the substrate-coating compatibility,achieving a critical load of 87.8 N.Silicon doping induced nanocrystallization and amorphization,increasing the hardness to 26 GPa.At high temperatures,a nanoscale Cr-rich(Cr,Al)_(2)O_(3) layer was formed,effectively inhibiting oxygen diffusion.The coating underwent unique phase transformations,during which Cr_(2)N and amorphous Si3N4 were converted into dispersed SiCr_(3) nanoparticles,which stabilized Cr atoms and suppressed their outward diffusion.Ab initio molecular dynamics simulations revealed that Cr atoms exhibited higher chemical activity and oxygen-capture capability than Al atoms and Si atoms served as diffusion barriers by pinning onto the oxidized surface,considerably improving the oxidation resistance of the coating.
基金financially supported by the National Program for Support of Top-notch Young Professionals,the Natural Science Foundation of Shaanxi Province(No.2023JC-XJ-04)the Postdoc-toral Innovative Talent Support Program(No.BX2021238)the National Natural Science Foundation of China(No.U22A20110).
文摘Al_(2)O_(3)scale-forming materials are highly desirable for high-temperature oxidation resistance,and the for-mation of α-Al_(2)O_(3)scales with low-angle grain boundaries(LAGBs)will increase their service lifetime.However,the synthesis of LAGBs is a considerable challenge.Herein,a novel methodology for engineering in situ α-Al_(2)O_(3)with LAGBs is designed,capitalizing on preferential nucleation.This approach employs a dual-stage preoxidation process,initiating with the selective nucleation of α-Al_(2)O_(3)under extremely low oxygen partial pressures,followed by the growth of these nuclei into a dense,protective oxide layer un-der marginally higher oxygen partial pressures.Based on this method,an α-Al_(2)O_(3)film with LAGBs is finally obtained,which significantly improves the oxidation resistance.This study not only paves the way for advanced materials to improve durability in high-temperature environments but also provides novel insight into the mechanisms of α-Al_(2)O_(3)film formation and growth under controlled oxidative conditions.
基金National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
基金supported by the Key Research and Development Program of Hebei Province(No.21373702D)the Key Science and Technology Program of HBIS Group Co.,Ltd.(No.HG2021117)+1 种基金the National Natural Science Foundation of China(No.52370124)the National Key R&D Program of China(No.2023YFC3707003).
文摘About 70%of the flue gas in the iron-steel industry has achieved multi-pollutant ultra-low emissions in China until 2023,and then the blast furnace gas purification has become the control step and bottleneck.Our research group has designed and constructed the world’s first blast furnace gas desulfurization pilot plant with the scale of 2000 Nm^(3)/h in October 2021.The pilot plant is a two-step combined desulfurization device including catalytic hydrolysis of carbonyl sulfur(COS)and absorption-oxidation of H_(2)S,continuously running for 120 days.In the hydrolysis system,one reason for catalyst deactivation has been verified from the sulfur deposition.HCN in blast furnace gas can be hydrolyzed on the hydrolysis catalyst to produce the nitrogen deposition,which is one of the reasons for catalyst deactivation and has never been found in previous studies.The deposition forms of S and N elements are determined,S element forms elemental sulfur and sulfate,while N element forms-NH_(2)and NH_(4)^(+).In the absorption-oxidation system,the O_(2)loading and the residence time have been optimized to control the oxidation of HS^(−)to produce elemental sulfur instead of by-product S_(2)O_(3)^(2−).The balance and distribution of S and N elements have been calculated for thewholemulti-phase system,approximately 84.4%of the sulfur is converted to solid sulfur product,about 1.3%of the sulfur and 19.2%of N element are deposited on the hydrolysis catalyst.The pilot plant provides technical support formulti-pollutant control of blast furnace.
基金Research on Problems and Countermeasures in Building the Capacity of the Grassroots International Chambers of Commerce in the Context of High-Quality Development (W2024H03841)a key research project of the China Council for the Promotion of International Trade in 2025。
文摘Arbitration is a key non-litigation commercial mechanism for the resolution of disputes, and the quality and credibility of its awards depend largely on the competency of the arbitrators. However, the selection and evaluation systems for arbitrators in China have long faced challenges such as the vague criteria for competency and an unclear professionalization path for arbitrators. To address these issues, this study is grounded in the context of actual Chinese arbitration practice and based on the competency iceberg model. Through a methodological approach encompassing literature reviews, behavioral event interviews, expert revisions, and questionnaire surveys, a Chinese Arbitrator Competency Scale was developed and validated in this study. Examination of the findings indicated that the scale needed to consist of five dimensions—communication and coordination, cognitive skills, ethical conduct, work motivation, and personality traits—and possess a total of 28 specific indicators. Confirmatory analysis of the factors demonstrates a good fit for the five-dimensional model, with each of the dimensions exhibiting high reliability and validity. This scale is innovative in integrating the competency elements with Chinese characteristics, such as commercial acumen, crosscultural mediation skills, and adaptability to the local rule of law. This research not only enriches the competency theory in regard to the field of human resource management but also provides a scientific framework of standards and measurement tools for the selection, training, and evaluation of arbitrators. It thus has significant practical value for enhancing the professionalism and international competitiveness of China's arbitration system.
基金supported by the Key R&D Program of Shandong Province,China(No.2025CXGC 010412)the National Key Research and Development Program of China(No.2022YFB3709300)the National Natural Science Foundation of China(No.U21A2048).
文摘The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
基金supported by Science and Technology Standard Project of Guangdong Electric Power Design Institute(ER11301W,ER11811W).
文摘Data center industries have been facing huge energy challenges due to escalating power consumption and associated carbon emissions.In the context of carbon neutrality,the integration of data centers with renewable energy has become a prevailing trend.To advance the renewable energy integration in data centers,it is imperative to thoroughly explore the data centers’operational flexibility.Computing workloads and refrigeration systems are recognized as two promising flexible resources for power regulationwithin data centermicro-grids.This paper identifies and categorizes delay-tolerant computing workloads into three types(long-running non-interruptible,long-running interruptible,and short-running)and develops mathematical time-shifting models for each.Additionally,this paper examines the thermal dynamics of the computer room and derives a time-varying temperature model coupled to refrigeration power.Building on these models,this paper proposes a two-stage,multi-time scale optimization scheduling framework that jointly coordinates computing workloads time-shift in day-ahead scheduling and refrigeration power control in intra-day dispatch to mitigate renewable variability.A case study demonstrates that the framework effectively enhances the renewable-energy utilization,improves the operational economy of the data center microgrid,and mitigates the impact of renewable power uncertainty.The results highlight the potential of coordinated computing workloads and thermal system flexibility to support greener,more cost-effective data center operation.
基金supported by the Fund for Innovative Research Group of the National Natural Science Foundation of China (Grant No.52221003)。
文摘The spatial optimization of best management practices(BMPs) plays a critical role in precise watershed pollution control. However, the effectiveness of BMPs exhibits a complex nonlinear dependence on both configuration unit scale and rainfall intensity, often leading to widespread spatiotemporal mismatches during implementation. To fill this gap, this study proposes a new framework:(a) delineating configuration units based on the implementation scale differences between structural and nonstructural BMPs;(b) incorporating BMP reduction thresholds to enable dynamic adjustment of design scales according to inflow loads;and(c) developing a staged allocation strategy tailored to varying rainfall scenarios. The framework is exemplified by an agricultural catchment in the southeastern Liaohe watershed, China. The results showed that the framework could improve the assessment accuracy and cost-effectiveness of pollution control. Specifically, neglecting BMP reduction thresholds resulted in a 51.35% underestimation of treatment costs. Incorporating these thresholds and dynamically adjusting BMP design scales reduced treatment costs by 62.70%. Furthermore, the framework facilitated more precise localization of structural BMPs(1 km^(2)) and improved optimization efficiency by 95.91%. The proposed staged allocation strategy ensured water quality compliance under varying rainfall intensities. Structural BMPs primarily addressed pollution from light to moderate rainfall in the initial stage, while nonstructural BMPs targeted heavy rainfall pollution in the subsequent stage. The proposed framework may enhance the spatiotemporal adaptability of BMP configuration to respond to the threats posed by climate change and human activities. It can also be extended to other agriculture-dominated watersheds.
基金supported by the National Key Research and Development Program of China(2024YFA1612900)the National Natural Science Foundation of China(Grant No.52103365 and No.12375270)the Guangdong Innovative and Entrepreneurial Research Team Program,China(Grant No.2021ZT09L227).
文摘Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,understanding the oxidation behavior of nuclear graphite is essential for reactor safety.The influence of oxidation involves multiple factors,including temperature,sample size,oxidant,impurities,filler type and size,etc.The size of the filler particles plays a crucial role in this study.Five ultrafine-and superfine-grained nuclear graphite samples(5.9-34.4μm)are manufactured using identical raw materials and manufacturing processes.Isothermal oxidation tests conducted at 650℃-750℃ are used to study the oxidation behavior.Additionally,comprehensive characterization is performed to analyze the crystal structure,surface morphology,and nanoscale to microscale pore structure of the samples.Results indicate that oxidation behavior cannot be predicted solely based on filler grain size.Reactive site concentration,characterized by active surface area,dominates the chemical reaction kinetics,whereas pore tortuosity,quantified by the structural parameterΨ,plays a key role in regulating oxidant diffusion.These findings clarify the dual role of microstructure in oxidation mechanisms and establish a theoretical and experimental basis for the design of high-performance nuclear graphite capable of long-term service in high-temperature gas-cooled reactors.
基金financially supported by the National Natural Science Foundation of China (22472199)Chinese Universities Scientific Fund (15055009)Central University Guided Funds for Building World-Class Universities (Disciplines) and Advancing Characteristic Development
文摘Electrocatalytic glucose oxidation to high-value chemicals provides a sustainable route for biomass valorization.NiCo-based catalysts have emerged as promising candidates for glucose oxidation reaction owing to the intrinsic activity of Ni and Co catalytic centers.However,the dynamic evolution and atomic-scale synergy between these centers remain elusive.Herein,we fabricated NiCo_(2)O_(4)nanosheets supported on nickel foam,where Ni preferentially occupies tetrahedral sites to regulate the electronic configuration of octahedral Co.Experimental and theoretical results demonstrate that the incorporation of tetrahedral Ni induces low-to-intermediate spin transition in octahedral Co,thereby optimizing eg orbital occupancy and stabilizing active sites.This spin-state engineering establishes Ni-Co synergistic catalytic centers for the selective oxidation of glucose to formate(FA).At higher potential(≥1.4 V vs.RHE),octahedral Co undergoes reconstruction into excessive active CoOOH and CoO_(2)species,resulting in glucose overoxidation to CO_(2)and intensified competitive oxygen evolution.In contrast,at lower potentials(<1.4 V vs.RHE),tetrahedral Ni facilitates electron delocalization across the Ni–O–Co lattice,thereby stabilizing octahedral Co for glucose adsorption and oxidation.Subsequently,a coupled electrocatalytic system was constructed,achieving 80.7%FA yield with 91.3%Faradaic efficiency(FE)at NiCo_(2)O_(4)anode and H2 evolution rate of 696μmol h^(−1)with 99.9%FE at Pt cathode for 2 h under 1.35 V vs.RHE.This work provides a deep insight into spin-state regulation of the catalytic center,offering valuable guidance for rational catalyst design.
基金supported by grants from the National Natural Science Foundation of China(Nos.22108154,22138006,32171430).
文摘Triterpenoids are valuable medicinal scaffolds,characterized by excellent pharmacological properties and the presence of hydroxyl and carboxyl groups that allow for further structural modifications.Expanding the scope of oxidative modifications on these molecules is crucial for increasing their synthetic structural diversity and unlocking new potential pharmacological activities.However,the progress has been limited by the scarcity of suitable tailoring enzymes.Here,we reported a break-through in achieving targeted and remote dual-site oxidation of licorice triterpenoids using a single P450 mutant.This approach successfully enabled the selective synthesis of the rare triterpenoid,liquiritic acid and 24-OH-liquiritic acid.Our findings demonstrate that microenvironmental accessibility engineering of triterpenoid substrates within the P450 enzyme is essential for continuous and regioselective oxidation.This study not only sheds light on the mechanistic aspects of P450 catalysis but also expands the enzymatic toolkit for selective oxidative modifications in triterpenoid biosynthesis.
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)+4 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 2025119The XAS experiments were conducted in Beijing Synchrotron Radiation Facility(BSRF)and Shanghai Synchrotron Radiation Facility(SSRF).
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supported by the National Natural Science Foundation of China(22075040,U21A20330,22131004)the National Key R&D Program of China(2022YFB3805900)+2 种基金the Jilin Provincial Scientific and Technological Development Program(20240602105RC)the Innovation Platform for Academicians of Hainan Provincethe Specific Research Fund of the Innovation Platform for Academicians of Hainan Province(YSPTZX202321)。
文摘The development of efficient photocatalysts for crucial organic transformation,such as aerobic oxidation,remains challenging.Although powdered porous materials offer abundant accessible active sites,their application in liquid-phase catalysis is often limited by insufficient light absorption and inevitable charge recombination,which are inherent drawbacks of conventional heterogeneous catalysts.Here,through rational design and nanoscale-engineering of porous aromatic frameworks(PAFs)comprising porphyrin and porous organic cage,a quasi-homogeneous porous photocatalyst with high catalytic activity and controllable dimension was developed.The interface-directed growth in oil-in-water emulsion shaped the morphology of photoactive PAFs from powders to nanoflakes,which facilitated the light absorbance and catalyst-substrate interaction.Compared with PAF powders,PAF nanoflakes exhibited superior photocatalytic activity for aerobic oxidation.For mustard gas simulant(2-chloroethyl ethyl sulfide,CEES),PAF nanoflakes exhibited ultrafast detoxification rates in room air with a half-life(t_(1/2))as fast as 26s,which even exceeded other catalysts in pure oxygen.It also completely catalyzed the aerobic oxidation of thioether within 15 min,which is almost the fastest rate among any reported organic photocatalysts.Furthermore,the efficient catalytic performance under mild conditions caused by improved light enrichment,surface charge transfer and carrier lifetime was elucidated.
基金support from the Australian Research Council(ARC)Linkage Project(No.LP230100166).
文摘Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert grinding media often fail to discriminate ef-fectively between pyrite and valuable copper minerals due to strong copper activation on pyrite surfaces.This study introduced a novel approach using inorganic radicals generated from peroxymonosulfate(PMS)to selectively oxidize and depress pyrite.Flotation tests with synthetic high-pyrite ore blends showed that PMS significantly reduced pyrite recovery while maintaining or improving chalcopyrite flot-ation.Ethylenediaminetetraacetic acid(EDTA)extraction confirmed selective oxidation of pyrite,and electron paramagnetic resonance(EPR)spectroscopy identified hydroxyl(·OH)and sulfate(SO_(4)^(·-))radicals as the dominant reactive species.Iron ions from grinding me-dia and mineral surfaces were identified as key activators of PMS.A major insight was pyrite’s dual role,acting both as a radical scav-enger and an activator,which made it highly reactive and susceptible to radical-induced oxidation.This process converted surface copper-sulfur species into copper hydroxides,effectively suppressing pyrite flotation.While previous studies have applied EPR to detect radicals in simplified activator/precursor systems,this study provides the first direct mechanistic evidence of radical-driven selectivity in flotation by detecting inorganic radicals in a complex flotation slurry,thereby demonstrating their persistence under industrially relevant conditions and establishing a foundation for more effective and targeted flotation strategies.
基金supported by the National Natural Science Foundation of China(22279079 and 22472101)Guangdong Science and Technology Department Program(2021QN02L252,2023A1515010021,and 2024A1515011543)Research Team Cultivation Program of Shenzhen University(2023QNT007)。
文摘Multi-site coupling is a promising strategy for developing highly efficient and CO-resistant hydrogen oxidation reaction(HOR)catalysts for proton exchange membrane fuel cells(PEMFCs).However,designing multifunctional synergistic schemes for single-atom sites remains a significant challenge.Herein,we propose a dual-template-confined oxophilic engineering strategy to construct well-dispersed iridium-nickel(IrNi)atomic dimers adjacent to IrNi nanoclusters on porous nitrogen-doped carbon(IrNi_(Dimer/NC1.8)-PNC).The paired IrNi dimer features an asymmetric Ir-N_(3)configuration coordinated with heteroatomic Ni-N_(3)O via an N-bridge.Remarkably,IrNi_(Dimer/NC1.8)-PNC exhibits a~23-fold enhancement in mass activity(4.36 A mg-1Ir at 20 mV)and 5-fold longer stability compared to benchmarking Pt/C toward HOR,while achieving a high rated power density of 1.18 W cm^(-2)in PEMFC anode applications.Furthermore,IrNi_(Dimer/NC1.8)-PNC demonstrates superior CO tolerance over monometallic Ir and Pt/C in both half-cell and full-cell devices.Combined experimental and density functional theory studies reveal that oxophilic Ni modulates the electronic environment of Ir through alloying and dimer interactions,thereby enhancing HOR activity.Importantly,the asymmetric IrNi dimer enables efficient CO^(*)and OH^(*)co-adsorption while facilitating CO_(2)^(*)desorption,synergistically mitigating CO poisoning and improving atom utilization efficiency.This work provides a design strategy and fundamental insights for multi-site synergistic catalysts in PEMFC anodes.
基金supported by the National Natural Science Foundation of China(Grant number 22172112)and the Fundamental Research Funds for the Central Universities.
文摘Electrocatalytic oxidation of glycerol for value-added chemicals is a superior strategy to utilize the excess glycerol produced in the biodiesel industry.Pd is one of the few active catalysts for alkaline glycerol oxidation reaction(GOR);however,glycerol inevitably dissociates and converts to carbon dioxide on the Pd surface,which results in its low total Faradaic efficiency(FE)for high-value-added products.Herein,a series of Pd/C and Pd10Bix/C catalysts were synthesized to investigate the GOR pathway.The Pd10Bi3/C catalyst with optimal Bi content achieved an excellent GOR mass activity of 7.5±0.2 A mgPd−1 and an outstanding total FE of 90%±3%,which are much higher than those values on Pd/C(1.2±0.2 A mgPd−1 for mass activity and 63%±4%for total FE).Combined results of in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy and density functional theory calculations show that Bi suppresses the dissociation of glycerol through the“shielding effect”of Bi to the adjacent Pd sites,which weakens the adsorption strength of GOR intermediates on those sites.This work provides a new insight into the GOR mechanism and puts forward a valid strategy for the rational design of catalysts to enable the transformation of glycerol into high-value-added products.
基金financially supported by the Sichuan Science and Technology Program (Grant No. 2025NSFSC0139)the China Postdoctoral Science Foundation (Grant No.2023MD734228)+10 种基金funding from Generalitat de Catalunya 2021SGR00457supported by MCIN with funding from European Union NextGenerationEU(PRTR-C17.I1)by Generalitat de Catalunya (In-CAEM Project)the support from the project AMaDE(PID2023-149158OB-C43)funded by MCIN/AEI/10.13039/501100011033/by “ERDF A way of making Europe”by the “European Union”supported by the Severo Ochoa program from Spanish MCIN/AEI (Grant No.:CEX2021-001214-S)funded by the CERCA Programme/Generalitat de Catalunyaperformed in the framework of Universitat Autònoma de Barcelona Materials Science PhD programfunding from the CSC-UAB PhD scholarship program. ICN2 is founding member of e-DREAM[87]
文摘The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts remains a primary challenge.In this study,an enhancement in catalytic MOR performance is achieved through the incorporation of Mn atoms with unsaturated t_(2g)orbitals into Ni_(3)Se_(4).Comprehensive experimental analyses and theoretical calculations reveal that substituting Ni with Mn induces strong electron-withdrawing effects,effectively modulating the local coordination environment of the metal centers.The presence of Mn also elongates Ni–Se(O)bonds,which reduces eg orbital occupancy and modifies the spin state of the material.Electrochemical measurements demonstrate that electrodes based on this optimized material exhibit a high spin state and deliver excellent catalytic activity,achieving a MOR current density up to∼190 mA cm^(−2)at 1.6 V.This performance enhancement is attributed to the favorable electronic configuration and reduced reaction energy barriers associated with the high-spin state.
基金Under the auspices of the National Natural Science Foundation of China(No.42371222,41971167)Fundamental Scientific Research Funds of Central China Normal University(No.CCNU24ZZ120)。
文摘Owing to intensified globalization and informatization,the structures of the urban scale hierarchy and urban networks between cities have become increasingly intertwined,resulting in different spatial effects.Therefore,this paper analyzes the spatial interaction between urban scale hierarchy and urban networks in China from 2019 to 2023,drawing on Baidu migration data and employing a spatial simultaneous equation model.The results reveal a significant positive spatial correlation between cities with higher hierarchy and those with greater network centrality.Within a static framework,we identify a positive interaction between urban scale hierarchy and urban network centrality,while their spatial cross-effects manifest as negative neighborhood interactions based on geographical distance and positive cross-scale interactions shaped by network connections.Within a dynamic framework,changes in urban scale hierarchy and urban networks are mutually reinforcing,thereby widening disparities within the urban hierarchy.Furthermore,an increase in a city’s network centrality had a dampening effect on the population growth of neighboring cities and network-connected cities.This study enhances understanding of the spatial organisation of urban systems and offers insights for coordinated regional development.
