Oxygen evolution and oxygen reduction are considered as essential processes in the energy conversion devices.The progress of cost-effective bifunctional catalysts has become a critical issue to be solved.Here,we repor...Oxygen evolution and oxygen reduction are considered as essential processes in the energy conversion devices.The progress of cost-effective bifunctional catalysts has become a critical issue to be solved.Here,we report that Co(OH)_(2)@N-doped carbon(NC)was facilely synthesized through the impregnation strategy of metal-organic frameworks derived carbon and cobalt ions.N-doped carbon with porous structure and cobalt hydroxide nanosheets play a synergistic effect role,representing excellent catalytic performance toward oxygen evolution and reduction reactions.The obtained Co(OH)_(2)@NC exhibits remarkable activity in terms of a lower overpotential of 330 mV@10 mA cm^(-2) for OER and a more positive half-wave potential(E_(1/2)=0.84 V)for ORR in alkaline medium,outperforming IrO_(2) and Pt/C.Due to its superior bifunctional catalytic performance,Co(OH)_(2)@NC catalyst is applied into a promising air electrode of Zn-air battery.This presented strategy of impregnation synthesis in this work provides a new design direction for practical electrochemical energy devices.展开更多
Inspired by hexaazanaphthalene-based conjugated copper metal-organic framework(HATNA-Cu-MOF),we designed 161 HATNA-TM-MOF-based SACs(TM@N_(x)O_(4-x)-HATNA)with varying TM or ligands creating distinct coordination envi...Inspired by hexaazanaphthalene-based conjugated copper metal-organic framework(HATNA-Cu-MOF),we designed 161 HATNA-TM-MOF-based SACs(TM@N_(x)O_(4-x)-HATNA)with varying TM or ligands creating distinct coordination environments(x=0-4)with superior thermodynamic and electrochemical stabilities.Volcano plots can be constructed using(AGOOH^(*)-ΔGO^(*))/ΔGO^(*)as descriptors for oxygen evolution/reduction reaction(OER/ORR)activity,also serving as target parameters for machine learning(ML)models to identify high-performance OER/ORR catalysts.The efficient monofunctional and bifunctional electrocatalysts were successfully predicted,where the ML prediction results well matched the DFT calculation results.We employed Shapley additive explanations(SHAP)for feature analysis and utilized sure independence screening and sparsification operator(SISSO)for generalization.ML analyses reveal that TM-based OER/ORR activities predominantly correlate with three key descriptors:metallic atomic radius,d-orbital electron population,and the heat of formation of the oxide,demonstrating the pivotal role of TM's inherent electronic configuration and physicochemical characteristics in governing electrocatalytic efficacy.The constant-potential approach emphasizes the key role of electric double-layer capacitance in adjusting the kinetic barrier,where changes in the Fermi level influence the occupation of d-orbitals.Variations in electrochemical potential significantly alter the electronic structure of representative Rh@N_(1)O_(3)-HATNA,affecting both the Fermi level and adsorption properties,with the unique 4d^(8)5s^(1)configuration leading to inverted O_(2)adsorption energies as the potential decreases.This study contributes insights into the origin of oxygen evolution-reduction activity for the HATNA-TM-MOF-based SACs and reveals the fundamentals of structure-activity relationships for future applications.展开更多
Against the background of“carbon peak and carbon neutrality,”it is of great practical significance to develop non-blast furnace ironmaking technology for the sustainable development of steel industry.Carbon-bearing ...Against the background of“carbon peak and carbon neutrality,”it is of great practical significance to develop non-blast furnace ironmaking technology for the sustainable development of steel industry.Carbon-bearing iron ore pellet is an innovative burden of direct reduction ironmaking due to its excellent self-reducing property,and the thermal strength of pellet is a crucial metallurgical property that affects its wide application.The carbon-bearing iron ore pellet without binders(CIPWB)was prepared using iron concentrate and anthracite,and the effects of reducing agent addition amount,size of pellet,reduction temperature and time on the thermal compressive strength of CIPWB during the reduction process were studied.Simultaneously,the mechanism of the thermal strength evolution of CIPWB was revealed.The results showed that during the low-temperature reduction process(300-500℃),the thermal compressive strength of CIPWB linearly increases with increasing the size of pellet,while it gradually decreases with increasing the anthracite ratio.When the CIPWB with 8%anthracite is reduced at 300℃for 60 min,the thermal strength of pellet is enhanced from 13.24 to 31.88 N as the size of pellet increases from 8.04 to 12.78 mm.Meanwhile,as the temperature is 500℃,with increasing the anthracite ratio from 2%to 8%,the thermal compressive strength of pellet under reduction for 60 min remarkably decreases from 41.47 to 8.94 N.Furthermore,in the high-temperature reduction process(600-1150℃),the thermal compressive strength of CIPWB firstly increases and then reduces with increasing the temperature,while it as well as the temperature corresponding to the maximum strength decreases with increasing the anthracite ratio.With adding 18%anthracite,the thermal compressive strength of pellet reaches the maximum value at 800℃,namely 35.00 N,and obtains the minimum value at 1050℃,namely 8.60 N.The thermal compressive strength of CIPWB significantly depends on the temperature,reducing agent dosage,and pellet size.展开更多
Hydrogen evolution reaction(HER)is unavoidable in many electrochemical synthesis systems,such as CO_(2)reduction,N2reduction,and H_(2)O_(2)synthesis.It makes those electrochemical reactions with multiple electron-prot...Hydrogen evolution reaction(HER)is unavoidable in many electrochemical synthesis systems,such as CO_(2)reduction,N2reduction,and H_(2)O_(2)synthesis.It makes those electrochemical reactions with multiple electron-proton transfers more complex when determining kinetics and mass transfer information.Understanding how HER competes with other electrochemical reduction reactions is crucial for both fundamental studies and system performance improvements.In this study,we employed the oxygen reduction reaction(ORR)as a model reaction to investigate HER competition on a polycrystalline-Au surface,using a rotating ring and disk electrode.It’s proved that water molecules serve as the proton source for ORR in alkaline,neutral,and even acidic electrolytes,and a 4-electron process can be achieved when the overpotential is sufficiently high.The competition from H⁺reduction becomes noticeable at the H⁺concentration higher than 2 mmol L^(–1)and intensi-fies as the H^(+)concentration increases.Based on the electrochemical results,we obtained an equivalent circuit diagram for the ORR system with competition from the H+reduction reaction,showing that these reactions occur in parallel and compete with each other.Electrochemical impedance spectroscopy measurements further confirm this argument.Additionally,we discover that the contribution of H+mass transfer to the total H^(+)reduction current is significant and comparable to the kinetic current.We believe this work will deepen our understanding of HER and its competition in electrochemical reduction systems.展开更多
Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seri...Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seriously limited the overall conversion efficiencies of solar energy to chemical fuels.Herein,we demonstrated a facile and feasible strategy to rationally regulate the coordination environment and electronic structure of surface-active sites on both photoanode and cathode.More specifically,the defect engineering has been employed to reduce the coordination number of ultrathin FeNi catalysts decorated on BiVO4 photoanodes,resulting in one of the highest OER activities of 6.51 mA cm^(−2)(1.23 VRHE,AM 1.5G).Additionally,single-atom cobalt(II)phthalocyanine anchoring on the N-rich carbon substrates to increase Co–N coordination number remarkably promotes CO_(2) adsorption and activation for high selective CO production.Their integration achieved a record activity of 109.4μmol cm^(−2) h−1 for CO production with a faradaic efficiency of>90%,and an outstanding solar conversion efficiency of 5.41%has been achieved by further integrating a photovoltaic utilizing the sunlight(>500 nm).展开更多
The development of single atom catalysts(SACs)with asymmetric active sites by defect regulation provides an encourage potential for oxygen reduction reaction(ORR)and hydrogen evolution reaction(HER),but highly challen...The development of single atom catalysts(SACs)with asymmetric active sites by defect regulation provides an encourage potential for oxygen reduction reaction(ORR)and hydrogen evolution reaction(HER),but highly challenging.Herein,N-doped carbon(N-C)anchored atomically dispersed Ni-N_(3)site with proximity defects(Ni-N_(3)D)induced by Te atoms doping is reported.Benefitting from the inductive effect of proximity defect,the Ni-N_(3)D/Te-N-C catalyst performs excellent ORR and HER performance in alkaline and acid condition.Both in situ characterization and theoretical calculation reveal that the existence of proximity defect effect is conducive to lower rate-determining-step energy barrier of ORR and HER,thus accelerating the multielectron reaction kinetics.This work paves a novel strategy for constructing highactivity bifunctional SACs by defect engineering for development of sustainable energy.展开更多
A novel photocatalytic cocatalyst, MoC quantum dots integrated into N-doped carbon microflowers (MoC–NC), was synthesized, establishing a key Mo–N interfacial bond. The Mo–N bond's regulation was achieved by ad...A novel photocatalytic cocatalyst, MoC quantum dots integrated into N-doped carbon microflowers (MoC–NC), was synthesized, establishing a key Mo–N interfacial bond. The Mo–N bond's regulation was achieved by adjusting the pH of Mo-polydopamine precursor solutions. A composite photocatalyst, MoC–NC/CdS (MNS), was formed by in situ growth of nano-CdS on MoC–NC. The pH during synthesis, crucial for Mo–N bond formation, significantly influenced Cr(Ⅵ) reduction and H_(2) evolution performance. The optimal MNS, created at pH 9.0, demonstrated 99.2% reduction efficiency for Cr(Ⅵ) in 20 min and H_(2) evolution rate of 11.4 mmol g^(-1) h^(-1) over 3 h, outperforming Pt/CdS. Mechanistic studies and density functional theory revealed MoC–NC's role in enhancing light absorption, reaction kinetics, and electron transport, attributing to its ultra-small quantum dots and abundant Mo–N bonds.展开更多
Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains...Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains a great challenge to avoid the inhomogeneous distribution and aggregation of metal single-atomic active centers in the construction of bifunctional electrocatalysts with atomically dispersed multimetallic sites because of the common calcination method.Herein,we report a novel catalyst with phthalocyanine-assembled Fe-Co-Ni single-atomic triple sites dispersed on sulfur-doped graphene using a simple ultrasonic procedure without calcination,and X-ray absorption fine structure(XAFS),aberration-corrected scanning transmission electron microscopy(AC-STEM),and other detailed characterizations are performed to demonstrate the successful synthesis.The novel catalyst shows extraordinary bifunctional ORR/OER activities with a fairly low potential difference(ΔE=0.621 V)between the OER overpotential(Ej10=315 mV at 10 m A cm^(-2))and the ORR half-wave potential(Ehalf-wave=0.924 V).Moreover,the above catalyst shows excellent ZAB performance,with an outstanding specific capacity(786 mAh g^(-1)),noteworthy maximum power density(139 mW cm^(-2)),and extraordinary rechargeability(discharged and charged at 5 mA cm^(-2) for more than 1000 h).Theoretical calculations reveal the vital importance of the preferable synergetic coupling effect between adjacent active sites in the Fe-Co-Ni trimetallic single-atomic sites during the ORR/OER processes.This study provides a new avenue for the investigation of bifunctional electrocatalysts with atomically dispersed trimetallic sites,which is intended for enhancing the ORR/OER performance in ZABs.展开更多
Optimizing active sites and enhancing mass transfer capability are of paramount importance for the improvement of electrocatalyst activity.On this basis,CoFe_(2)O_(4)/CoFe nanoparticles(NPs)loaded N-doped carbon(NC)th...Optimizing active sites and enhancing mass transfer capability are of paramount importance for the improvement of electrocatalyst activity.On this basis,CoFe_(2)O_(4)/CoFe nanoparticles(NPs)loaded N-doped carbon(NC)that featured with interconnected three-dimensional(3D)ordered porous hierarchies(3DOM FeCo/NC)are prepared,and its electrocatalytic activity is studied.Due to the open structure of 3D ordered macro-pores that greatly improves the mass transfer capacity of the catalytic process and enhances the utilization of active sites inside the catalyst,as well as the uniform distribution of Fe and Co bimetallic sites on the porous skeleton,3DOM FeCo/NC exhibits superior bi-functional catalytic activities for both hydrogen evolution reaction(HER)and oxygen reduction reaction(ORR).The overpotential of HER is lower than that of commercial Pt/C when performed at high current density(>235 mA cm^(-2))in1.0 M KOH,and the half-wave potential(0.896 V)of ORR in 0.1 M KOH is also superior to that of 20% commercial Pt/C and most other similar catalysts.The effective utilization and synergistic effect of CoFe_(2)O_(4)and CoFe hetero-metallic sites remarkably enhance the electrocatalytic activity.Furthermore,3DOM FeCo/NC is assembled as an air electrode in Zn-air battery,and exhibits satisfactory maximum power density,open-circuit voltage,and charge/discharge stability over benchmark Pt/C+IrO_(2).This work contributes new insights into the design of transition-metal-based multifunctional catalysts,and has great potential for energy conversion and storage.展开更多
The rational design of Ni-based catalysts is essential due to their abundance and low cost for advancing sustainable energy technologies,particularly for water splitting and fuel cells.This study employs spinpolarized...The rational design of Ni-based catalysts is essential due to their abundance and low cost for advancing sustainable energy technologies,particularly for water splitting and fuel cells.This study employs spinpolarized density functional theory(DFT)to examine the influence of anchoring rare-earth elements on the γ-NiOOH lattice surface,aiming to identify the optimal catalytic site for the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Following the identification of an appropriate active site through Ni vacancy,a rare earth element(REE_(1))is introduced as a dopant for single-atom catalysis(SACs).The structural,thermodynamic,and catalytic characteristics of all newly designed REE_(1)/γ-NiOOH catalysts have been extensively studied.Among the newly developed catalysts,Tb_(1)/γ-NiOOH exhibits the lowest OER overpotential of(0.36 V),while Ce_(1)/γ-NiOOH and Pr_(1)/γ-NiOOH also demonstrate excellent OER performance(0.51 and 0.41 V),respectively.Notably,Nd_(1)/γ-NiOOH and Pm_(1)/γ-NiOOH exhibit efficient ORR activity,with low overpotentials of(0.63 and 0.61 V)due to their balanced adsorption and desorption energies of intermediates.Bader charge analysis reveals strong electron donation from doped REE1to the surface.This study identified Ce_(1),Pr_(1),Nd_(1),and Tb_(1) anchoring catalysts as highly promising for water-splitting applications.Moreover,Nd_(1) and Pm_(1) doping markedly improve ORR performance,underscoring their promise for enhanced electrochemical applications in metal-air batteries.The catalytic performance of all newly developed catalysts was further evaluated using electronic descriptors.The catalytic performance was further assessed using the volcano curve and scaling relationships for the adsorbed intermediates.This study offers an extensive theoretical foundation for designing cost-effective and high-performance REE_(1)/γ-NiOOH electrocatalysts.展开更多
Owing to their multi-elemental compositions and unique high-entropy mixing states,high-entropy alloy(HEA)nanoparticles(NPs)displaying tunable activities and enhanced stabilities thus have become a rapidly growing area...Owing to their multi-elemental compositions and unique high-entropy mixing states,high-entropy alloy(HEA)nanoparticles(NPs)displaying tunable activities and enhanced stabilities thus have become a rapidly growing area of research in recent years.However,the integration of multiple elements into HEA NPs at the nanoscale remains a formidable challenge,especially when it comes to the precise control of particle size,elemental composition and content.Herein,a simple and universal high-energy laser assisted reduction approach is presented,which achieves the preparation of HEA NPs with a wide range of multi-component,controllable particle sizes and constitution on different substrates within seconds.Laser on carbon nanofibers induced momentary high-temperature annealing(>2000 K and ramping/cooling rates>10^(5)K s^(-1))to successfully decorate HEA NPs up to twenty elements with excellent compatibility for large-scale synthesis(20.0×20.0 cm^(2)of carbon cloth).The IrPdPtRhRu exhibit robust electrocatalytic hydrogen evolution reaction(HER)activities and low overpotentials of 16,28,and 12 mV at a current density of 10 mA cm^(-2)in alkaline(1.0 M KOH),alkaline simulated seawater(1.0 M KOH+0.5 M NaCl),and acidic(0.5 M H_(2)SO_(4))electrolytes,respectively,and excellent stability(7 days and>2000 cycles)at the alkaline HER.展开更多
Mg-3Gd(wt.%)samples with different initial grain sizes were prepared to evaluate the grain size effect on microstructural evolution during cold rolling and subsequent annealing hardening response.The deformation behav...Mg-3Gd(wt.%)samples with different initial grain sizes were prepared to evaluate the grain size effect on microstructural evolution during cold rolling and subsequent annealing hardening response.The deformation behavior and mechanical response of the as-rolled and annealed samples were systematically investigated by a combination of electron microscopy and microhardness characterization.The results show that the twinning activities were highly suppressed in the fine-grained samples during rolling.Upon increasing the rolling reduction to 40%,ultra-fine grain structures with a volume fraction of∼28%were formed due to the activation of multiple slip systems.Conversely,twinning dominated the early stages of deformation in the coarse-grained samples.After a 10%rolling reduction,numerous twins with a volume fraction of∼23%were formed.Further increasing the rolling reduction to 40%,high-density dislocations were activated and twin structures with a volume fraction of∼36%were formed.The annealing hardening response of deformed samples was effectively enhanced compared to that of the non-deformed samples,which was attributed to the enhanced Gd segregation along grain boundaries,twin boundaries and dislocation cores.Moreover,the grain size and rolling reduction were found to affect the microstructure evolution during annealing,resulting in a notable difference in the annealing hardening response of Mg-3Gd alloy between samples of different grain sizes deformed to different strains.These findings highlight the crucial importance of microstructural and processing parameters in the design of high-strength,cost-effective Mg alloys.展开更多
Solar-induced water oxidation reaction(WOR)for oxygen evolution is a critical step in the transformation of Earth's atmosphere from a reducing to an oxidation one during its primordial stages.WOR is also associate...Solar-induced water oxidation reaction(WOR)for oxygen evolution is a critical step in the transformation of Earth's atmosphere from a reducing to an oxidation one during its primordial stages.WOR is also associated with important reduction reactions,such as oxygen reduction reaction(ORR),which leads to the production of hydrogen peroxide(H_(2)O_(2)).These transitions are instrumental in the emergence and evolution of life.In this study,transition metals were loaded onto nitrogen-doped carbon(NDC)prepared under the primitive Earth's atmospheric conditions.These metal-loaded NDC samples were found to catalyze both WOR and ORR under light illumination.The chemical pathways initiated by the pristine and metal-loaded NDC were investigated.This study provides valuable insights into potential mechanisms relevant to the early evolution of our planet.展开更多
The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The diffe...The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The difference of mechanical properties between the Cu and 1010 steel causes different thickness reductions,percentage spread,and cladding ratios.The formation of strong texture induces larger strength of the rolled samples,and as the volume fraction of 1010 steel is larger in Route-A,its strength is consistently greater than that in Route-B.The obstruction of interface to crystal and dislocation slip results in the formation of interface distortion,inducing dislocation density gradient when the rolling reduction is low in Route-A.The slip planes of the Cu and 1010 steel are more prone to suffer the normal strain,while the shear strain of other crystal planes is obviously larger than the normal strain under rolling load near the interface.展开更多
Thiadiamondoids(TDs)have recently attracted increasing attention as molecular proxies for thermochemical sulfate reduction(TSR)reactions in reservoirs.However,their formation mechanisms,as well as the generation and e...Thiadiamondoids(TDs)have recently attracted increasing attention as molecular proxies for thermochemical sulfate reduction(TSR)reactions in reservoirs.However,their formation mechanisms,as well as the generation and evolution processes,remain poorly understood.In this study,simulation experiments with a duration of 160 h were conducted on the model compound 1,3-dimethyladamantane(1,3-DMA)using the CaSO_(4),MgSO_(4),and elemental S systems,with measurements at the 10th,20th,40th,80th and 160th hours during the simulation process being presented.The results indicate that at the end of simulation,the MgSO_(4) system exhibited the lowest residual amounts of 1,3-DMA,suggesting the highest degree of TSR.Four types of non-hydrocarbon compounds with adamantane structures were detected in the liquid products in the three experiment systems:adamantanones,adamantanols,adamantanethiols(ATs),and thiaadamantanes(TAs).Among these,adamantanones exhibited the highest concentrations in the three simulation systems.In addition,TAs were dominated by C_(3)-TAs in the CaSO_(4) and MgSO_(4) systems and by C_(2)-TAs in the elemental S system.The simulation experiments revealed a strong correlation between the concentrations of TAs and adamantanones,suggesting that adamantanones might be the intermediates for TAs.Combined with the synthesis mechanism of TAs from thiaadamamantane-4,8-dione,TDs might have two different genetic mechanisms:(a)low temperature cationic carbon ion rearrangement from diagenesis to early catagenesis stage,and(b)a free sulfur radical mechanism in high-temperature TSR process during middle-late catagenesis.TAs exhibited different generation and evolution processes across different experiment systems.Notably,the MgSO_(4) system revealed that TAs undergo generation,accumulation,and destruction process,corresponding to Easy%Ro values of 0.89%-0.98%,0.98%-1.21%,and>1.21%,respectively.Among these three simulation systems,dibenzothiophenes(DBTs)concentrations consistently trended upwards,indicating TAs have lower thermal stability than DBTs.展开更多
In order to improve the performance of the attribute reduction algorithm to deal with the noisy and uncertain large data, a novel co-evolutionary cloud-based attribute ensemble multi-agent reduction（CCAEMR） algorith...In order to improve the performance of the attribute reduction algorithm to deal with the noisy and uncertain large data, a novel co-evolutionary cloud-based attribute ensemble multi-agent reduction（CCAEMR） algorithm is proposed.First, a co-evolutionary cloud framework is designed under the M apReduce mechanism to divide the entire population into different co-evolutionary subpopulations with a self-adaptive scale. Meanwhile, these subpopulations will share their rewards to accelerate attribute reduction implementation.Secondly, a multi-agent ensemble strategy of co-evolutionary elitist optimization is constructed to ensure that subpopulations can exploit any correlation and interdependency between interacting attribute subsets with reinforcing noise tolerance.Hence, these agents are kept within the stable elitist region to achieve the optimal profit. The experimental results show that the proposed CCAEMR algorithm has better efficiency and feasibility to solve large-scale and uncertain dataset problems with complex noise.展开更多
Due to the fact that conventional heuristic attribute reduction algorithms are poor in running efficiency and difficult in accomplishing the co-evolutionary reduction mechanism in the decision table, an adaptive multi...Due to the fact that conventional heuristic attribute reduction algorithms are poor in running efficiency and difficult in accomplishing the co-evolutionary reduction mechanism in the decision table, an adaptive multicascade attribute reduction algorithm based on quantum-inspired mixed co-evolution is proposed. First, a novel and efficient self- adaptive quantum rotation angle strategy is designed to direct the participating populations to mutual adaptive evolution and to accelerate convergence speed. Then, a multicascade model of cooperative and competitive mixed co-evolution is adopted to decompose the evolutionary attribute species into subpopulations according to their historical performance records, which can increase the diversity of subpopulations and select some elitist individuals so as to strengthen the sharing ability of their searching experience. So the global optimization reduction set can be obtained quickly. The experimental results show that, compared with the existing algorithms, the proposed algorithm can achieve a higher performance for attribute reduction, and it can be considered as a more competitive heuristic algorithm on the efficiency and accuracy of minimum attribute reduction.展开更多
Noble metals, such as platinum, ruthenium and iridium‐group metals, are often used as oxygen reduction or evolution reaction （ORR/OER） electrocatalysts. To reduce the cost and provide an application of bifunctional...Noble metals, such as platinum, ruthenium and iridium‐group metals, are often used as oxygen reduction or evolution reaction （ORR/OER） electrocatalysts. To reduce the cost and provide an application of bifunctional catalysis, in this work, cobalt oxide supported on nitrogen and phospho‐rus co‐doped carbon （Co3O4/NPC） was fabricated and examined as a bifunctional electrocatalyst for OER and ORR. To prepare Co3O4/NPC, NPC was pyrolyzed from melamine and phytic acid support‐ed on carbon, followed by the solvothermal synthesis of Co3O4 on NPC. Linear sweep voltammetry was used to evaluate the activity for OER and ORR. For OER, Co3O4/NPC showed an onset potential of 0.54 V （versus the saturated calomel electrode） and a current density of 21.95 mA/cm2 at 0.80 V, which was better than both Co3O4/C and NPC. The high activity of Co3O4/NPC was attributed to a synergistic effect of the N, P co‐dopants and Co3O4. For ORR, Co3O4/NPC exhibited an activity close to commercial Pt/C in terms of the diffusion limited current density （–4.49 vs–4.76 mA/cm2 at–0.80 V）, and Co3O4 played the key role for the catalysis. Chronoamperometry （current versus time） was used to evaluate the stability, which showed that Co3O4/NPC maintained 46%current after the chronoamperometry test for OER and 95% current for ORR. Overall, Co3O4/NPC exhibited high activity and improved stability for both OER and ORR.展开更多
A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and...A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.展开更多
The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecul...The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.91963113,51701139,and U1601216)。
文摘Oxygen evolution and oxygen reduction are considered as essential processes in the energy conversion devices.The progress of cost-effective bifunctional catalysts has become a critical issue to be solved.Here,we report that Co(OH)_(2)@N-doped carbon(NC)was facilely synthesized through the impregnation strategy of metal-organic frameworks derived carbon and cobalt ions.N-doped carbon with porous structure and cobalt hydroxide nanosheets play a synergistic effect role,representing excellent catalytic performance toward oxygen evolution and reduction reactions.The obtained Co(OH)_(2)@NC exhibits remarkable activity in terms of a lower overpotential of 330 mV@10 mA cm^(-2) for OER and a more positive half-wave potential(E_(1/2)=0.84 V)for ORR in alkaline medium,outperforming IrO_(2) and Pt/C.Due to its superior bifunctional catalytic performance,Co(OH)_(2)@NC catalyst is applied into a promising air electrode of Zn-air battery.This presented strategy of impregnation synthesis in this work provides a new design direction for practical electrochemical energy devices.
基金financially supported by the National Natural Science Foundation of China(Nos.62264015 and U2233206)the Civil Aviation Administration of China(No.U1933109)Hubei Province Technology Innovation Program Project(No.2024BCB073)
文摘Inspired by hexaazanaphthalene-based conjugated copper metal-organic framework(HATNA-Cu-MOF),we designed 161 HATNA-TM-MOF-based SACs(TM@N_(x)O_(4-x)-HATNA)with varying TM or ligands creating distinct coordination environments(x=0-4)with superior thermodynamic and electrochemical stabilities.Volcano plots can be constructed using(AGOOH^(*)-ΔGO^(*))/ΔGO^(*)as descriptors for oxygen evolution/reduction reaction(OER/ORR)activity,also serving as target parameters for machine learning(ML)models to identify high-performance OER/ORR catalysts.The efficient monofunctional and bifunctional electrocatalysts were successfully predicted,where the ML prediction results well matched the DFT calculation results.We employed Shapley additive explanations(SHAP)for feature analysis and utilized sure independence screening and sparsification operator(SISSO)for generalization.ML analyses reveal that TM-based OER/ORR activities predominantly correlate with three key descriptors:metallic atomic radius,d-orbital electron population,and the heat of formation of the oxide,demonstrating the pivotal role of TM's inherent electronic configuration and physicochemical characteristics in governing electrocatalytic efficacy.The constant-potential approach emphasizes the key role of electric double-layer capacitance in adjusting the kinetic barrier,where changes in the Fermi level influence the occupation of d-orbitals.Variations in electrochemical potential significantly alter the electronic structure of representative Rh@N_(1)O_(3)-HATNA,affecting both the Fermi level and adsorption properties,with the unique 4d^(8)5s^(1)configuration leading to inverted O_(2)adsorption energies as the potential decreases.This study contributes insights into the origin of oxygen evolution-reduction activity for the HATNA-TM-MOF-based SACs and reveals the fundamentals of structure-activity relationships for future applications.
基金support of the National Natural Science Foundation of China(52074080,52004001,and 51574002).
文摘Against the background of“carbon peak and carbon neutrality,”it is of great practical significance to develop non-blast furnace ironmaking technology for the sustainable development of steel industry.Carbon-bearing iron ore pellet is an innovative burden of direct reduction ironmaking due to its excellent self-reducing property,and the thermal strength of pellet is a crucial metallurgical property that affects its wide application.The carbon-bearing iron ore pellet without binders(CIPWB)was prepared using iron concentrate and anthracite,and the effects of reducing agent addition amount,size of pellet,reduction temperature and time on the thermal compressive strength of CIPWB during the reduction process were studied.Simultaneously,the mechanism of the thermal strength evolution of CIPWB was revealed.The results showed that during the low-temperature reduction process(300-500℃),the thermal compressive strength of CIPWB linearly increases with increasing the size of pellet,while it gradually decreases with increasing the anthracite ratio.When the CIPWB with 8%anthracite is reduced at 300℃for 60 min,the thermal strength of pellet is enhanced from 13.24 to 31.88 N as the size of pellet increases from 8.04 to 12.78 mm.Meanwhile,as the temperature is 500℃,with increasing the anthracite ratio from 2%to 8%,the thermal compressive strength of pellet under reduction for 60 min remarkably decreases from 41.47 to 8.94 N.Furthermore,in the high-temperature reduction process(600-1150℃),the thermal compressive strength of CIPWB firstly increases and then reduces with increasing the temperature,while it as well as the temperature corresponding to the maximum strength decreases with increasing the anthracite ratio.With adding 18%anthracite,the thermal compressive strength of pellet reaches the maximum value at 800℃,namely 35.00 N,and obtains the minimum value at 1050℃,namely 8.60 N.The thermal compressive strength of CIPWB significantly depends on the temperature,reducing agent dosage,and pellet size.
文摘Hydrogen evolution reaction(HER)is unavoidable in many electrochemical synthesis systems,such as CO_(2)reduction,N2reduction,and H_(2)O_(2)synthesis.It makes those electrochemical reactions with multiple electron-proton transfers more complex when determining kinetics and mass transfer information.Understanding how HER competes with other electrochemical reduction reactions is crucial for both fundamental studies and system performance improvements.In this study,we employed the oxygen reduction reaction(ORR)as a model reaction to investigate HER competition on a polycrystalline-Au surface,using a rotating ring and disk electrode.It’s proved that water molecules serve as the proton source for ORR in alkaline,neutral,and even acidic electrolytes,and a 4-electron process can be achieved when the overpotential is sufficiently high.The competition from H⁺reduction becomes noticeable at the H⁺concentration higher than 2 mmol L^(–1)and intensi-fies as the H^(+)concentration increases.Based on the electrochemical results,we obtained an equivalent circuit diagram for the ORR system with competition from the H+reduction reaction,showing that these reactions occur in parallel and compete with each other.Electrochemical impedance spectroscopy measurements further confirm this argument.Additionally,we discover that the contribution of H+mass transfer to the total H^(+)reduction current is significant and comparable to the kinetic current.We believe this work will deepen our understanding of HER and its competition in electrochemical reduction systems.
基金supported by the National Natural Science Foundation of China(21832005,22072168,22002175)Major Program of the Lanzhou Institute of Chemical Physics,CAS(No.ZYFZFX-3)+1 种基金Major Science and Technology Projects in Gansu Province(22ZD6GA003)West Light Foundation of The Chinese Academy of Sciences(xbzg-zdsys-202209).
文摘Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seriously limited the overall conversion efficiencies of solar energy to chemical fuels.Herein,we demonstrated a facile and feasible strategy to rationally regulate the coordination environment and electronic structure of surface-active sites on both photoanode and cathode.More specifically,the defect engineering has been employed to reduce the coordination number of ultrathin FeNi catalysts decorated on BiVO4 photoanodes,resulting in one of the highest OER activities of 6.51 mA cm^(−2)(1.23 VRHE,AM 1.5G).Additionally,single-atom cobalt(II)phthalocyanine anchoring on the N-rich carbon substrates to increase Co–N coordination number remarkably promotes CO_(2) adsorption and activation for high selective CO production.Their integration achieved a record activity of 109.4μmol cm^(−2) h−1 for CO production with a faradaic efficiency of>90%,and an outstanding solar conversion efficiency of 5.41%has been achieved by further integrating a photovoltaic utilizing the sunlight(>500 nm).
基金financially supported by the National Natural Science Foundation of China(22478432,22108306,22178388)Taishan Scholars Program of Shandong Province(tsqn201909065)+2 种基金Shandong Provincial Natural Science Foundation(ZR2024JQ004)Innovation Fund Project for Graduate Student of China University of Petroleum(East China)the Fundamental Research Funds for the Central Universities(No.25CX04020A)。
文摘The development of single atom catalysts(SACs)with asymmetric active sites by defect regulation provides an encourage potential for oxygen reduction reaction(ORR)and hydrogen evolution reaction(HER),but highly challenging.Herein,N-doped carbon(N-C)anchored atomically dispersed Ni-N_(3)site with proximity defects(Ni-N_(3)D)induced by Te atoms doping is reported.Benefitting from the inductive effect of proximity defect,the Ni-N_(3)D/Te-N-C catalyst performs excellent ORR and HER performance in alkaline and acid condition.Both in situ characterization and theoretical calculation reveal that the existence of proximity defect effect is conducive to lower rate-determining-step energy barrier of ORR and HER,thus accelerating the multielectron reaction kinetics.This work paves a novel strategy for constructing highactivity bifunctional SACs by defect engineering for development of sustainable energy.
基金supported by the National Natural Science Foundation of China(Nos.22078118 and 42277219)the Natural Science Foundation of Guangdong Province,China(No.2023A1515010740).
文摘A novel photocatalytic cocatalyst, MoC quantum dots integrated into N-doped carbon microflowers (MoC–NC), was synthesized, establishing a key Mo–N interfacial bond. The Mo–N bond's regulation was achieved by adjusting the pH of Mo-polydopamine precursor solutions. A composite photocatalyst, MoC–NC/CdS (MNS), was formed by in situ growth of nano-CdS on MoC–NC. The pH during synthesis, crucial for Mo–N bond formation, significantly influenced Cr(Ⅵ) reduction and H_(2) evolution performance. The optimal MNS, created at pH 9.0, demonstrated 99.2% reduction efficiency for Cr(Ⅵ) in 20 min and H_(2) evolution rate of 11.4 mmol g^(-1) h^(-1) over 3 h, outperforming Pt/CdS. Mechanistic studies and density functional theory revealed MoC–NC's role in enhancing light absorption, reaction kinetics, and electron transport, attributing to its ultra-small quantum dots and abundant Mo–N bonds.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.22305071,52472200,52271176,and52072114)the 111 Project(Grant No.D17007)+3 种基金Henan Center for Outstanding Overseas Scientists(Grant No.GZS2022017)the China Postdoctoral Science Foundation(Grant No.2022M721049)the Henan Province Key Research and Development Project(Grant No.231111520500)the Natural Science Foundation of Henan Province(Grant No.252300421556)。
文摘Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains a great challenge to avoid the inhomogeneous distribution and aggregation of metal single-atomic active centers in the construction of bifunctional electrocatalysts with atomically dispersed multimetallic sites because of the common calcination method.Herein,we report a novel catalyst with phthalocyanine-assembled Fe-Co-Ni single-atomic triple sites dispersed on sulfur-doped graphene using a simple ultrasonic procedure without calcination,and X-ray absorption fine structure(XAFS),aberration-corrected scanning transmission electron microscopy(AC-STEM),and other detailed characterizations are performed to demonstrate the successful synthesis.The novel catalyst shows extraordinary bifunctional ORR/OER activities with a fairly low potential difference(ΔE=0.621 V)between the OER overpotential(Ej10=315 mV at 10 m A cm^(-2))and the ORR half-wave potential(Ehalf-wave=0.924 V).Moreover,the above catalyst shows excellent ZAB performance,with an outstanding specific capacity(786 mAh g^(-1)),noteworthy maximum power density(139 mW cm^(-2)),and extraordinary rechargeability(discharged and charged at 5 mA cm^(-2) for more than 1000 h).Theoretical calculations reveal the vital importance of the preferable synergetic coupling effect between adjacent active sites in the Fe-Co-Ni trimetallic single-atomic sites during the ORR/OER processes.This study provides a new avenue for the investigation of bifunctional electrocatalysts with atomically dispersed trimetallic sites,which is intended for enhancing the ORR/OER performance in ZABs.
基金financially supported by the National Natural Science Foundation of China(51902149,51674131,22305108)the Fundamental Research Funds for Public Universities in Liaoning(LJ232410140033)the Scientific Research Funding of the Education Department of Liaoning Province(JYTZD2023070,LJKFZ20220180,LJKMZ20220453)。
文摘Optimizing active sites and enhancing mass transfer capability are of paramount importance for the improvement of electrocatalyst activity.On this basis,CoFe_(2)O_(4)/CoFe nanoparticles(NPs)loaded N-doped carbon(NC)that featured with interconnected three-dimensional(3D)ordered porous hierarchies(3DOM FeCo/NC)are prepared,and its electrocatalytic activity is studied.Due to the open structure of 3D ordered macro-pores that greatly improves the mass transfer capacity of the catalytic process and enhances the utilization of active sites inside the catalyst,as well as the uniform distribution of Fe and Co bimetallic sites on the porous skeleton,3DOM FeCo/NC exhibits superior bi-functional catalytic activities for both hydrogen evolution reaction(HER)and oxygen reduction reaction(ORR).The overpotential of HER is lower than that of commercial Pt/C when performed at high current density(>235 mA cm^(-2))in1.0 M KOH,and the half-wave potential(0.896 V)of ORR in 0.1 M KOH is also superior to that of 20% commercial Pt/C and most other similar catalysts.The effective utilization and synergistic effect of CoFe_(2)O_(4)and CoFe hetero-metallic sites remarkably enhance the electrocatalytic activity.Furthermore,3DOM FeCo/NC is assembled as an air electrode in Zn-air battery,and exhibits satisfactory maximum power density,open-circuit voltage,and charge/discharge stability over benchmark Pt/C+IrO_(2).This work contributes new insights into the design of transition-metal-based multifunctional catalysts,and has great potential for energy conversion and storage.
基金supported by the BRICS STI Framework Programme(No.52261145703)the Higher Education Discipline Innovation Project(National 111 Project,No.B16016)。
文摘The rational design of Ni-based catalysts is essential due to their abundance and low cost for advancing sustainable energy technologies,particularly for water splitting and fuel cells.This study employs spinpolarized density functional theory(DFT)to examine the influence of anchoring rare-earth elements on the γ-NiOOH lattice surface,aiming to identify the optimal catalytic site for the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Following the identification of an appropriate active site through Ni vacancy,a rare earth element(REE_(1))is introduced as a dopant for single-atom catalysis(SACs).The structural,thermodynamic,and catalytic characteristics of all newly designed REE_(1)/γ-NiOOH catalysts have been extensively studied.Among the newly developed catalysts,Tb_(1)/γ-NiOOH exhibits the lowest OER overpotential of(0.36 V),while Ce_(1)/γ-NiOOH and Pr_(1)/γ-NiOOH also demonstrate excellent OER performance(0.51 and 0.41 V),respectively.Notably,Nd_(1)/γ-NiOOH and Pm_(1)/γ-NiOOH exhibit efficient ORR activity,with low overpotentials of(0.63 and 0.61 V)due to their balanced adsorption and desorption energies of intermediates.Bader charge analysis reveals strong electron donation from doped REE1to the surface.This study identified Ce_(1),Pr_(1),Nd_(1),and Tb_(1) anchoring catalysts as highly promising for water-splitting applications.Moreover,Nd_(1) and Pm_(1) doping markedly improve ORR performance,underscoring their promise for enhanced electrochemical applications in metal-air batteries.The catalytic performance of all newly developed catalysts was further evaluated using electronic descriptors.The catalytic performance was further assessed using the volcano curve and scaling relationships for the adsorbed intermediates.This study offers an extensive theoretical foundation for designing cost-effective and high-performance REE_(1)/γ-NiOOH electrocatalysts.
基金supported by the National Natural Science Foundation of China(Grant No.52072274 and 52104309)the Knowledge Innovation Project of Wuhan,China(2023020201010131).
文摘Owing to their multi-elemental compositions and unique high-entropy mixing states,high-entropy alloy(HEA)nanoparticles(NPs)displaying tunable activities and enhanced stabilities thus have become a rapidly growing area of research in recent years.However,the integration of multiple elements into HEA NPs at the nanoscale remains a formidable challenge,especially when it comes to the precise control of particle size,elemental composition and content.Herein,a simple and universal high-energy laser assisted reduction approach is presented,which achieves the preparation of HEA NPs with a wide range of multi-component,controllable particle sizes and constitution on different substrates within seconds.Laser on carbon nanofibers induced momentary high-temperature annealing(>2000 K and ramping/cooling rates>10^(5)K s^(-1))to successfully decorate HEA NPs up to twenty elements with excellent compatibility for large-scale synthesis(20.0×20.0 cm^(2)of carbon cloth).The IrPdPtRhRu exhibit robust electrocatalytic hydrogen evolution reaction(HER)activities and low overpotentials of 16,28,and 12 mV at a current density of 10 mA cm^(-2)in alkaline(1.0 M KOH),alkaline simulated seawater(1.0 M KOH+0.5 M NaCl),and acidic(0.5 M H_(2)SO_(4))electrolytes,respectively,and excellent stability(7 days and>2000 cycles)at the alkaline HER.
基金financial support from the National Key Research and Development Program of China(No.2021YFB3702101)National Natural Science Foundation of China(No.52130107,52071038)+5 种基金Fundamental Research Funds for the Central Universities(No.2023CDJXY-018)the“111”Project(No.B16007)by the Ministry of Education and the State Administration of Foreign Experts Affairs of Chinasupport to the Norwegian Micro-and Nano-Fabrication Facility,NorFab(No.295864)the Norwegian Laboratory for Mineral and Materials Characterization,MiMaC(No.269842/F50)the RCN INRPART project IntMat(No.309724)the Center for Research based Innovation SFI PhysMet(No.309584).
文摘Mg-3Gd(wt.%)samples with different initial grain sizes were prepared to evaluate the grain size effect on microstructural evolution during cold rolling and subsequent annealing hardening response.The deformation behavior and mechanical response of the as-rolled and annealed samples were systematically investigated by a combination of electron microscopy and microhardness characterization.The results show that the twinning activities were highly suppressed in the fine-grained samples during rolling.Upon increasing the rolling reduction to 40%,ultra-fine grain structures with a volume fraction of∼28%were formed due to the activation of multiple slip systems.Conversely,twinning dominated the early stages of deformation in the coarse-grained samples.After a 10%rolling reduction,numerous twins with a volume fraction of∼23%were formed.Further increasing the rolling reduction to 40%,high-density dislocations were activated and twin structures with a volume fraction of∼36%were formed.The annealing hardening response of deformed samples was effectively enhanced compared to that of the non-deformed samples,which was attributed to the enhanced Gd segregation along grain boundaries,twin boundaries and dislocation cores.Moreover,the grain size and rolling reduction were found to affect the microstructure evolution during annealing,resulting in a notable difference in the annealing hardening response of Mg-3Gd alloy between samples of different grain sizes deformed to different strains.These findings highlight the crucial importance of microstructural and processing parameters in the design of high-strength,cost-effective Mg alloys.
基金supported by the National Key Technologies R&D Program of China(Nos.2022YFE0114800 and 2021YFA1502100)National Natural Science Foundation of China(Nos.22075047,22032002,U1905214,21961142019)the 111 Project(Nos.D16008)。
文摘Solar-induced water oxidation reaction(WOR)for oxygen evolution is a critical step in the transformation of Earth's atmosphere from a reducing to an oxidation one during its primordial stages.WOR is also associated with important reduction reactions,such as oxygen reduction reaction(ORR),which leads to the production of hydrogen peroxide(H_(2)O_(2)).These transitions are instrumental in the emergence and evolution of life.In this study,transition metals were loaded onto nitrogen-doped carbon(NDC)prepared under the primitive Earth's atmospheric conditions.These metal-loaded NDC samples were found to catalyze both WOR and ORR under light illumination.The chemical pathways initiated by the pristine and metal-loaded NDC were investigated.This study provides valuable insights into potential mechanisms relevant to the early evolution of our planet.
基金the National Key Research and Development Program of China(No.2018YFE0306103)the National Natural Science Foundation of China(No.52071050)+1 种基金the Science and Technology Innovation Project of Ningbo,China(No.2021Z032)the Program of China Scholarships Council(No.202106060148).
文摘The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The difference of mechanical properties between the Cu and 1010 steel causes different thickness reductions,percentage spread,and cladding ratios.The formation of strong texture induces larger strength of the rolled samples,and as the volume fraction of 1010 steel is larger in Route-A,its strength is consistently greater than that in Route-B.The obstruction of interface to crystal and dislocation slip results in the formation of interface distortion,inducing dislocation density gradient when the rolling reduction is low in Route-A.The slip planes of the Cu and 1010 steel are more prone to suffer the normal strain,while the shear strain of other crystal planes is obviously larger than the normal strain under rolling load near the interface.
基金funded by the Natural Science Foundation of China(Grants Nos.42272167,U24B6001,and 41772153)Science&Technology Project of Sinopec(Grant Nos.P23167 and P24173).
文摘Thiadiamondoids(TDs)have recently attracted increasing attention as molecular proxies for thermochemical sulfate reduction(TSR)reactions in reservoirs.However,their formation mechanisms,as well as the generation and evolution processes,remain poorly understood.In this study,simulation experiments with a duration of 160 h were conducted on the model compound 1,3-dimethyladamantane(1,3-DMA)using the CaSO_(4),MgSO_(4),and elemental S systems,with measurements at the 10th,20th,40th,80th and 160th hours during the simulation process being presented.The results indicate that at the end of simulation,the MgSO_(4) system exhibited the lowest residual amounts of 1,3-DMA,suggesting the highest degree of TSR.Four types of non-hydrocarbon compounds with adamantane structures were detected in the liquid products in the three experiment systems:adamantanones,adamantanols,adamantanethiols(ATs),and thiaadamantanes(TAs).Among these,adamantanones exhibited the highest concentrations in the three simulation systems.In addition,TAs were dominated by C_(3)-TAs in the CaSO_(4) and MgSO_(4) systems and by C_(2)-TAs in the elemental S system.The simulation experiments revealed a strong correlation between the concentrations of TAs and adamantanones,suggesting that adamantanones might be the intermediates for TAs.Combined with the synthesis mechanism of TAs from thiaadamamantane-4,8-dione,TDs might have two different genetic mechanisms:(a)low temperature cationic carbon ion rearrangement from diagenesis to early catagenesis stage,and(b)a free sulfur radical mechanism in high-temperature TSR process during middle-late catagenesis.TAs exhibited different generation and evolution processes across different experiment systems.Notably,the MgSO_(4) system revealed that TAs undergo generation,accumulation,and destruction process,corresponding to Easy%Ro values of 0.89%-0.98%,0.98%-1.21%,and>1.21%,respectively.Among these three simulation systems,dibenzothiophenes(DBTs)concentrations consistently trended upwards,indicating TAs have lower thermal stability than DBTs.
基金The National Natural Science Foundation of China(No.61300167)the Open Project Program of State Key Laboratory for Novel Software Technology of Nanjing University(No.KFKT2015B17)+3 种基金the Natural Science Foundation of Jiangsu Province(No.BK20151274)Qing Lan Project of Jiangsu Provincethe Open Project Program of Key Laboratory of Intelligent Perception and Systems for High-Dimensional Information of Ministry of Education(No.JYB201606)the Program for Special Talent in Six Fields of Jiangsu Province(No.XYDXXJS-048)
文摘In order to improve the performance of the attribute reduction algorithm to deal with the noisy and uncertain large data, a novel co-evolutionary cloud-based attribute ensemble multi-agent reduction（CCAEMR） algorithm is proposed.First, a co-evolutionary cloud framework is designed under the M apReduce mechanism to divide the entire population into different co-evolutionary subpopulations with a self-adaptive scale. Meanwhile, these subpopulations will share their rewards to accelerate attribute reduction implementation.Secondly, a multi-agent ensemble strategy of co-evolutionary elitist optimization is constructed to ensure that subpopulations can exploit any correlation and interdependency between interacting attribute subsets with reinforcing noise tolerance.Hence, these agents are kept within the stable elitist region to achieve the optimal profit. The experimental results show that the proposed CCAEMR algorithm has better efficiency and feasibility to solve large-scale and uncertain dataset problems with complex noise.
基金The National Natural Science Foundation of China(No. 61139002,61171132)the Funding of Jiangsu Innovation Program for Graduate Education (No. CXZZ11_0219 )+2 种基金the Natural Science Foundation of Jiangsu Province (No. BK2010280)the Open Project of Jiangsu Provincial Key Laboratory of Computer Information Processing Technology (No. KJS1023)the Applying Study Foundation of Nantong(No. BK2011062)
文摘Due to the fact that conventional heuristic attribute reduction algorithms are poor in running efficiency and difficult in accomplishing the co-evolutionary reduction mechanism in the decision table, an adaptive multicascade attribute reduction algorithm based on quantum-inspired mixed co-evolution is proposed. First, a novel and efficient self- adaptive quantum rotation angle strategy is designed to direct the participating populations to mutual adaptive evolution and to accelerate convergence speed. Then, a multicascade model of cooperative and competitive mixed co-evolution is adopted to decompose the evolutionary attribute species into subpopulations according to their historical performance records, which can increase the diversity of subpopulations and select some elitist individuals so as to strengthen the sharing ability of their searching experience. So the global optimization reduction set can be obtained quickly. The experimental results show that, compared with the existing algorithms, the proposed algorithm can achieve a higher performance for attribute reduction, and it can be considered as a more competitive heuristic algorithm on the efficiency and accuracy of minimum attribute reduction.
基金supported by the National Natural Science Foundation of China (21375016,20475022 and 21505019)~~
文摘Noble metals, such as platinum, ruthenium and iridium‐group metals, are often used as oxygen reduction or evolution reaction （ORR/OER） electrocatalysts. To reduce the cost and provide an application of bifunctional catalysis, in this work, cobalt oxide supported on nitrogen and phospho‐rus co‐doped carbon （Co3O4/NPC） was fabricated and examined as a bifunctional electrocatalyst for OER and ORR. To prepare Co3O4/NPC, NPC was pyrolyzed from melamine and phytic acid support‐ed on carbon, followed by the solvothermal synthesis of Co3O4 on NPC. Linear sweep voltammetry was used to evaluate the activity for OER and ORR. For OER, Co3O4/NPC showed an onset potential of 0.54 V （versus the saturated calomel electrode） and a current density of 21.95 mA/cm2 at 0.80 V, which was better than both Co3O4/C and NPC. The high activity of Co3O4/NPC was attributed to a synergistic effect of the N, P co‐dopants and Co3O4. For ORR, Co3O4/NPC exhibited an activity close to commercial Pt/C in terms of the diffusion limited current density （–4.49 vs–4.76 mA/cm2 at–0.80 V）, and Co3O4 played the key role for the catalysis. Chronoamperometry （current versus time） was used to evaluate the stability, which showed that Co3O4/NPC maintained 46%current after the chronoamperometry test for OER and 95% current for ORR. Overall, Co3O4/NPC exhibited high activity and improved stability for both OER and ORR.
文摘A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.
文摘The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.
