Cu-based metal-organic frameworks(Cu-MOFs)electrocatalysts are promising for CO_(2)reduction reactions(CO_(2)RR)to produce valuable C_(2+)products.However,designing suitable active sites in Cu-MOFs remains challenging...Cu-based metal-organic frameworks(Cu-MOFs)electrocatalysts are promising for CO_(2)reduction reactions(CO_(2)RR)to produce valuable C_(2+)products.However,designing suitable active sites in Cu-MOFs remains challenging due to their inherent structural instability during CO_(2)RR.Here we propose a synergistic strategy through thermal annealing and electrochemicalactivation process for in-situ reconstruction of the pre-designed Cu-MOFs to produce abundant partially oxidized Cu(Cu^(δ+))active species.The optimized MOF-derived Cu^(δ+)electrocatalyst demonstrates a highly selective production of C_(2+)products,with the Faradaic Efficiency(FE)of 78±2%and a partial current density of-46 m A cm-2at-1.06 VRHEin a standard H-type cell.Our findings reveal that the optimized Cu^(δ+)-rich surface remains stable during electrolysis and enhances surface charge transfer,leading to an increase in the concentration of*CO intermediates,thereby highly selectively producing C_(2+)compounds.This study advances the controllable formation of MOF-derived Cu^(δ+)-rich surfaces and strengthens the understanding of their catalytic role in CO_(2)RR for C_(2+)products.展开更多
Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains un...Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications.展开更多
Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level curren...Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level current densities.Although atomically dispersed Platinum(Pt)catalysts offer significant potential for enhancing atom utilization,their HER performance and durability are limited by the inflexibility in valence electron transfer between Pt and the support.In this study,we utilize asymmetrically single-atom copper(Cu)with tunable valence states as a valence electron reservoir(VER)to dynamically regulate the Pt 5d valence states,achieving efficient alkaline HER.In situ synchrotron radiation and theoretical calculations demonstrate that the dynamic evolution of the Pt 5d valence electron configuration optimizes the adsorption strengths of reaction intermediates.Meanwhile,single-atom Cu accelerates the rate-limiting water dissociation,and Pt facilitates subsequent^(*)H coupling.The catalyst requires only 23.5 and 177.2 mV overpotentials to achieve current densities of 10 and 500 mA cm^(-2)in 1 M KOH.Notably,the PtCu/NC exhibits a~57%lower hydrogen evolution barrier than Pt/NC.Moreover,the PtCu/NC-based AEMWE operates for over 600 h at an industrially relevant current density of 500 mA cm^(-2).展开更多
The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by...The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by numerical simulation and experiment.Falling film flow of high viscosity fluids was found to be steady on a vertical wavy wall in the presence of the large film thickness.The comparison between numerical simulation and experiment for the film thickness both in crest and trough of wavy wall showed good agreement.The simulation results of average residence time of falling film flow with different viscous fluids were also consistent with the experimental results.This work provides the initial insights of how to evaluate and optimize the falling film flow system of polymer fluid.展开更多
The N-doped bismuth tungstate （BizWOt） photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samoles were characteri...The N-doped bismuth tungstate （BizWOt） photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samoles were characterized by X-ray diffraction, scanning electron microscopy, specific surface area, photocurrent analysis, and UV-Vis diffuse re- flectrance spectroscopy. The photocatalytic activity was evaluated by photocatalytic degradation of rhodamine B （RhB） solution under visible light irradiation. The photocatalytic mechanisms were analyzed by active species trapping experi- ments which revealed that the holes were the main active species of N-doped BizWO6 products in aqueous solution under visible light irradiation, rather than .OH and O-. With the assistance of H202, the photocatalytic activity for degradation of RhB could be further improved because H202 reacted with conduction band electrons to generate more hydroxyl radicals. KEY WORDS：展开更多
The monoaminotrinitro iron phthalocyanine(FeMATNPc)is used to connect with isonicotinic acid(INA)for amide bonding and axial coordination to synthetic a unique catalyst FeMATNPc-INA,which is loaded in polyacrylonitril...The monoaminotrinitro iron phthalocyanine(FeMATNPc)is used to connect with isonicotinic acid(INA)for amide bonding and axial coordination to synthetic a unique catalyst FeMATNPc-INA,which is loaded in polyacrylonitrile(PAN)nanofibers by electrospinning.The introduction of INA destroys theπ-πconjugated stack structure in phthalocyanine molecules and exposes more active sites.The FeMATNPc-INA structure is characterized by X-ray photoelectron spectroscopy and UV-visible absorption spectrum,and the FeMATNPcINA/PAN structure is characterized by Fourier transform infrared spectroscopy and X-ray diffraction.The FeMATNPc-INA/PAN can effectively activate peroxymonosulfate(PMS)to eliminate carbamazepine(CBZ)within 40 minutes(PMS 1.5 mmol/L)in the dark.The effects of catalyst dosage,PMS concentration,pH and inorganic anion on the degradation of CBZ are investigated.It has been confirmed by electron paramagnetic resonance,gas chromatography–mass spectroscopy and free radical capture experiments that the catalytic system is degraded by·OH,SO4^(·-)and Fe(IV)=O are the major active species,the singlet oxygen(^(1)O_(2))is the secondary active species.The degradation process of CBZ is analyzed by ultra-high performance liquid chromatography-mass spectrometry and the aromatic compounds have been degraded to small molecular acids.展开更多
Metal phthalocyanine has been extensively studied as a catalyst for degradation of carbamazepine(CBZ).However,metal phthalocyanine tends to undergo their own dimerization or polymerization,thereby reducing their activ...Metal phthalocyanine has been extensively studied as a catalyst for degradation of carbamazepine(CBZ).However,metal phthalocyanine tends to undergo their own dimerization or polymerization,thereby reducing their activity points and affecting their catalytic properties.In this study,a catalytic system consisting of O-bridged iron perfluorophthalocyanine dimers(FePcF16-O-FePcF16),multi-walled carbon nanotubes(MWCNTs)and H2O_(2) was proposed.The results showed MWCNTs loaded with FePcF16-O-FePcF16 can achieve excellent degradation of CBZ with smaller dosages of FePcF16-O-FePcF16 and H2O_(2),and milder reaction temperatures.In addition,the results of experiments revealed the reaction mechanism of non-hydroxyl radicals.The highly oxidized high-valent iron-oxo(Fe(IV)=O)species was the main reactive species in the FePcF16-O-FePcF16/MWCNTs/H2O_(2) system.It is noteworthy that MWCNTs can improve the dispersion of FePcF16-O-FePcF16,contributing to the production of highly oxidized Fe(IV)=O.Then,the pathway of CBZ oxidative degradation was speculated,and the study results also provide new ideas for metal phthalocyanine-loaded carbon materials to degrade emerging pollutants.展开更多
Fe single-atom catalysts(Fe-SACs)have been extensively studied as a highly efficient electrocatalyst toward the oxygen reduction reaction(ORR).Nonetheless,they suffer from stability issue induced by dissolution of Fe ...Fe single-atom catalysts(Fe-SACs)have been extensively studied as a highly efficient electrocatalyst toward the oxygen reduction reaction(ORR).Nonetheless,they suffer from stability issue induced by dissolution of Fe metal center and the OH^(−)blocking.Herein,a surface molecular engineering strategy is developed by usingβ-cyclodextrins(CDs)as a localized molecular encapsulation.The CD-modified Fe-SAC(Fe-SNC-β-CD)shows obviously improved activity toward the ORR with 0.90 V,4.10 and 4.09 mA cm^(-2)for E_(1/2),J_(0)and Jk0.9,respectively.Meanwhile,the Fe-SNC-β-CD shows the excellent long-term stability against aggressive stress and the poisoning.It is confirmed through electrochemical investigation that modification ofβ-CD can,on one hand,regulate the atomic Fe coordination chemistry through the interaction between the CD and FeN_(x) moiety,while on the other mitigate the strong adsorption of OH^(−)and function as protective barrier against the poisoning molecules leading to enhanced ORR activity and stability for the Fe-SACs.The molecular encapsulation strategy demonstrates the uniqueness of post-pyrolysis surface molecular engineering for the design of single-atom catalyst.展开更多
Square and labyrinth-like titanium dioxide particles were successfully synthesized by a simple hydrothermal method with assistant of halloysite nanotubes. The morphology and microstructure of as-prepared photo-catalys...Square and labyrinth-like titanium dioxide particles were successfully synthesized by a simple hydrothermal method with assistant of halloysite nanotubes. The morphology and microstructure of as-prepared photo-catalysts were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The photo-catalytic activity of as-prepared catalysts was evaluated by degradation of organic pollutants（Rhodamine B, methylene blue and methanol） under UV light irradiation.展开更多
Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ...Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ultrathin carbon shell supported FePc molecule electrocatalysts(FePc/TA-ONG-N),featuring with a direct oxygen bridging between FePc and carbon substrate,were designed and synthesized.The direct connection with oxygen atom on carbon substrate,certified by the Fourier transform infrared spectroscopy(FTIR)and extended X-ray absorption fine structure(EXAFS),can remarkably enhance the interaction and facilitate electron transfer from Fe,leading to an improved activity by reducing adsorption strength of intermediate species through lowering the d-band center position.The resultant half-wave potential of 0.902 V together with a Tafel slope of 23.64 mV·dec^(−1)is superior to Pt/C and control samples.Such catalyst holds a promise as air-cathode electrocatalyst in Zn-air battery with excellent operation stability exceeding 80 h.The density functional theory(DFT)calculations and molecular dynamic simulations unveiled that the O-bridge can effectively stabilize the FePc molecule and function as electron buffer to donate/gain electrons to/from Fe atom during the adsorption of oxygenates.The current findings are insightful for developing molecular catalysts with high performance through substrate engineering and axial coordination.展开更多
Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron sp...Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron spectroscopy(APXPS)emerges as an emerging photon-in-electron-out technique in in-situ/operando analysis by bridging the pressure-gap between conventional ultra-high vacuum(UHV)and near ambient or even close to operating conditions,rendering the advancement of XPS from a UHV-based technique to a versatile and powerful tool that enables the specific probe of numerous events taking place at the gas–solid,liquid–solid and liquid–gas nanoscale interfaces which are critical to nanocatalysis research.For example,APXPS probes information on catalytically active phase and reaction kinetics in nanocatalytic processes;details inside the electric double-layer at an electrolyte/electrode interface can now be accessed;more efficient nanocatalyst design can be achieved and energy transfer venues can be optimized.Here,we aim to critically review the recent advances in instrumentation and the probe of the gas–solid,liquid–solid,and gas–liquid nanoscale interfaces using APXPS-based methodologies,followed by putting forward an outlook of development of APXPS as a rising in-situ/operando analytical means in surface science,nanocatalysis,nanoscience materials science.展开更多
The electrocatalytic C-N coupling reaction as a green synthesis approach for C-N bond synthesis via electrochemical processes with catalytic assistance.However,inefficient reactant adsorption onto the catalyst surface...The electrocatalytic C-N coupling reaction as a green synthesis approach for C-N bond synthesis via electrochemical processes with catalytic assistance.However,inefficient reactant adsorption onto the catalyst surface,competing side reactions,and the complexity and diversity of reaction pathways hinder its widespread application.Atomically dispersed catalysts(ADCs),as an emerging class of catalytic materials,possess precisely defined active sites,high catalytic activity,and enhanced selectivity,thereby enabling efficient electrocatalytic C-N coupling to address these challenges.This review discusses current reaction pathways for converting small molecules(CO_(2)as the carbon source,N_(2),NO_(2)^(-),NO_(3)^(-)as the nitrogen source)into high-value organic nitrogen compounds(urea,amides,oximes,and amino acids)utilizing ADCs.It specifically focuses on the critical steps within electrocatalytic C-N coupling facilitated by these catalysts,encompassing reactant adsorption,transformation and selective hydrogenation of C-/N-intermediates,and the C-N coupling reaction itself.Based on these key steps,design principles for ADCs are proposed.Finally,the synthesis strategies for ADCs-vacancy engineering,confinement strategies,and alloying-are examined,alongside the mechanisms by which they enhance catalytic activity and selectivity.展开更多
Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to ...Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to finely regulate their doping types and clarify their effect on the catalytic property of such catalysts.Herein,we report that the N-doping type in CN can be dominated as pyrrolic-N and pyridinic-N respectively through compounding with different metal oxides.It is found that the proportion of distinct doped N species in CN depends on the acidity and basicity of compounded metal oxide host.Owing to the coordination by pyrrolic-N,the SA Cu catalyst displays an enhanced activity(two-fold)for transfer hydrogenation of quinoline to access the valuable molecule tetrahydroquinoline with a good selectivity(99%)under mild conditions.The higher electron density of SA Cu species induced by the predominate pyrrolic-N coordination benefits the hydrogen transfer process and reduces the energy barrier of the hydrogenation pathway,which accounts for the improved catalytic effeciency.展开更多
Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber-Bosch process which accounts for 1.4% of the annual energy consumption. In this study, atomically dispe...Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber-Bosch process which accounts for 1.4% of the annual energy consumption. In this study, atomically dispersed Au_1 catalyst is synthesized and applied in electrochemical synthesis of ammonia under ambient conditions. A high NH＋4 Faradaic efficiency of 11.1 % achieved by our Au_1 catalyst surpasses most of reported catalysts under comparable conditions. Benefiting from efficient atom utilization, an NH＋4 yield rate of 1,305 μg h-1 mg-1Au has been reached, which is roughly 22.5 times as high as that by sup- ported Au nanoparticles. We also demonstrate that by employing our Au_1 catalyst, NH＋4 can be electro- chemically produced directly from N_2 and H_2 with an energy utilization rate of 4.02 mmol kJ-1. Our study provides a possibility of replacing the Haber-Bosch process with environmentally benign and energy-efficient electrochemical strategies.展开更多
The demand for high-performance non-precious-metal electrocatalysts to replace the noble metal-based catalysts for oxygen reduction reaction(ORR)is intensively increasing.Herein,single-atomic copper sites supported on...The demand for high-performance non-precious-metal electrocatalysts to replace the noble metal-based catalysts for oxygen reduction reaction(ORR)is intensively increasing.Herein,single-atomic copper sites supported on N-doped three-dimensional hierarchically porous carbon catalyst(Cu_(1)/NC)was prepared by coordination pyrolysis strategy.Remarkably,the Cu_(1)/NC-900 catalyst not only exhibits excellent ORR performance with a half-wave potential of 0.894 V(vs.RHE)in alkaline media,outperforming those of commercial Pt/C(0.851 V)and Cu nanoparticles anchored on N-doped porous carbon(CuNPs/NC-900),but also demonstrates high stability and methanol tolerance.Moreover,the Cu_(1)/NC-900 based Zn-air battery exhibits higher power density,rechargeability and cyclic stability than the one based on Pt/C.Both experimental and theoretical investigations demonstrated that the excellent performance of the as-obtained Cu_(1)/NC-900 could be attributed to the synergistic effect between copper coordinated by three N atoms active sites and the neighbouring carbon defect,resulting in elevated Cu d-band centers of Cu atoms and facilitating intermediate desorption for ORR process.This study may lead towards the development of highly efficient non-noble metal catalysts for applications in electrochemical energy conversion.展开更多
Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,dire...Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,directly anchoring metal single atoms on three-dimensional(3D)macro support,which is promising to achieve the heterogenization of homogeneous catalysis,remains a challenge and a blank in this field.Herein,we successfully fabricate metal single atoms(Pd,Pt,Ru,Au)on porous carbon nitride/reduced graphene oxide(C3N4/rGO)foam as highly efficient catalysts with convenient recyclability.C3N4/rGO foam features two-dimensional microstructures with abundant N chelating sites for the stabilization of metal single atoms and vertically-aligned hierarchical mesostructure that benefits the mass diffusion.The obtained Pdi/C3N4/rGO monolith catalyst exhibits much enhanced activity over its nanoparticle counterpart for Suzuki-Miyaura reaction.Moreover,the Pdi/C3N4/rGO monolith catalyst can be readily assembled in a flow reactor to achieve the highly efficient continuous production of 4-nitro-1,1'-biphenyl through Suzuki-Miyaura coupling.展开更多
Aberrant tumor blood vessels are prone to propel the malignant progression of tumors,and targeting abnormal metabolism of tumor endothelial cells emerges as a promising option to achieve vascular normalization and ant...Aberrant tumor blood vessels are prone to propel the malignant progression of tumors,and targeting abnormal metabolism of tumor endothelial cells emerges as a promising option to achieve vascular normalization and antagonize tumor progression.Herein,we demonstrated that salvianic acid A(SAA)played a pivotal role in contributing to vascular normalization in the tumor-bearing mice,thereby improving delivery and effectiveness of the chemotherapeutic agent.SAA was capable of inhibiting glycolysis and strengthening endothelial junctions in the human umbilical vein endothelial cells(HUVECs)exposed to hypoxia.Mechanistically,SAA was inclined to directly bind to the glycolytic enzyme PKM2,leading to a dramatic decrease in endothelial glycolysis.More importantly,SAA improved the endothelial integrity via activating theβ-Catenin/Claudin-5 signaling axis in a PKM2-dependent manner.Our findings suggest that SAA may serve as a potent agent for inducing tumor vascular normalization.展开更多
The design of non-noble metal heterogeneous catalyst with superior performance for selective hydrogenation or transfer hydrogenation of nitroarenes to amines is significant but challenging.Herein,a single-atom Fe supp...The design of non-noble metal heterogeneous catalyst with superior performance for selective hydrogenation or transfer hydrogenation of nitroarenes to amines is significant but challenging.Herein,a single-atom Fe supported by nitrogen-doped carbon(Fe_(1)/N-C)catalyst is reported.The Fe_(1)/N-C sample shows superior performances for the selective hydrogenation and transfer hydrogenation of nitrobenzene to aniline at different temperatures.Density functional theory(DFT)calculations show that the superior catalytic activity for the selective hydrogenation at lower temperatures could be attributed to the effective activation of the reactant and intermediates by the Fe_(1)/N-C.Moreover,the excellent performance of Fe_(1)/N-C for the selective transfer hydrogenation could be attributed to that the reaction energy barrier for dehydrogenation of isopropanol can be overcome by elevated temperatures.展开更多
Transition metal sulfides with homogeneous multi-metallic elements promise high catalytic performance for water electrolysis owing to the unique structure and highly tailorable electrochemical property.Most existing s...Transition metal sulfides with homogeneous multi-metallic elements promise high catalytic performance for water electrolysis owing to the unique structure and highly tailorable electrochemical property.Most existing synthetic routes require high temperature to ensure the uniform mixing of various elements,making the synthesis highly challenging.Here,for the first-time novel carbon fiber supported high-entropy Co-Zn-Cd-Cu-Mn sulfide(CoZnCdCuMnS@CF)nanoarrays are fabricated by the mild cation exchange strategy.Benefiting from the synergistic effect among multiple metals and the strong interfacial bonding between high-entropy Co-Zn-Cd-Cu-Mn sulfide nanoarrays and the carbon fiber support,CoZnCdCuMnS@CF exhibits superior catalytic activity and stability toward overall water splitting in alkaline medium.Impressively,CoZnCdCuMnS@CF only needs low overpotentials of 173 and 220 mV to reach the current density of 10 mA•cm^(−2),with excellent durability for over 70 and 113 h for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)respectively.More importantly,the bifunctional electrode(CoZnCdCuMnS@CF||CoZnCdCuMnS@CF)for overall water splitting can deliver a small cell voltage of 1.63 V to afford 10 mA•cm^(−2) and exhibit outstanding stability of negligible decay after 73 h continuous operation.This work provides a viable synthesis route toward advanced high-entropy materials with great potential applications.展开更多
The rational design of efficient single-atomic(SA)catalysts is essential and highly desirable but impeded by the lack of sufficient acknowledge between structure and property.To this end,it is critical to clarify the ...The rational design of efficient single-atomic(SA)catalysts is essential and highly desirable but impeded by the lack of sufficient acknowledge between structure and property.To this end,it is critical to clarify the effect of the coordination structure of active metal centers on the catalytic activities for the design of such catalysts.Here,we report that different coordination structures of SA Pt catalysts can dramatically influence their activities for anti-Markovnikov hydroboration of alkenes.Compared with the other two coordination structures(Pt-N4 and Pt-O2),the SA Pt species coordinated with three O atoms(Pt-O3)display the highest turnover number value of 3288 for the hydroboration reaction to access the important alkylboronic esters.Density functional theory calculations reveal that a superior catalytic activity can be expected for alkene hydroboration over the three O coordinated Pt species due to the lowest reaction energy(ΔG)limiting step from the reaction phase diagram.展开更多
基金supported by the Research Grants Council(16310419,16309418,and 16304821)the Innovation and Technology Commission(Grant No.ITC-CNERC14EG03)of the Hong Kong Special Administrative Region+4 种基金the Hong Kong Branch of National Precious Metals Material Engineering Research Centre,City University of Hong Kongthe Strategic Hiring Scheme of The Hong Kong Polytechnic University(P0047728)GuangDong Basic and Applied Basic Research Foundation(2023A1515110259)National Natural Science Foundation of China(22405228)Guangzhou Science and Technology Bureau(2024A03J0609)。
文摘Cu-based metal-organic frameworks(Cu-MOFs)electrocatalysts are promising for CO_(2)reduction reactions(CO_(2)RR)to produce valuable C_(2+)products.However,designing suitable active sites in Cu-MOFs remains challenging due to their inherent structural instability during CO_(2)RR.Here we propose a synergistic strategy through thermal annealing and electrochemicalactivation process for in-situ reconstruction of the pre-designed Cu-MOFs to produce abundant partially oxidized Cu(Cu^(δ+))active species.The optimized MOF-derived Cu^(δ+)electrocatalyst demonstrates a highly selective production of C_(2+)products,with the Faradaic Efficiency(FE)of 78±2%and a partial current density of-46 m A cm-2at-1.06 VRHEin a standard H-type cell.Our findings reveal that the optimized Cu^(δ+)-rich surface remains stable during electrolysis and enhances surface charge transfer,leading to an increase in the concentration of*CO intermediates,thereby highly selectively producing C_(2+)compounds.This study advances the controllable formation of MOF-derived Cu^(δ+)-rich surfaces and strengthens the understanding of their catalytic role in CO_(2)RR for C_(2+)products.
文摘Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications.
基金supported by the Ningbo Top-Talent Team Program,Program for the National Natural Science Foundation of China(22106166)the Yongjiang Innovative Individual Introduction of China,and the China Postdoctoral Science Foundation(2022M723253)。
文摘Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level current densities.Although atomically dispersed Platinum(Pt)catalysts offer significant potential for enhancing atom utilization,their HER performance and durability are limited by the inflexibility in valence electron transfer between Pt and the support.In this study,we utilize asymmetrically single-atom copper(Cu)with tunable valence states as a valence electron reservoir(VER)to dynamically regulate the Pt 5d valence states,achieving efficient alkaline HER.In situ synchrotron radiation and theoretical calculations demonstrate that the dynamic evolution of the Pt 5d valence electron configuration optimizes the adsorption strengths of reaction intermediates.Meanwhile,single-atom Cu accelerates the rate-limiting water dissociation,and Pt facilitates subsequent^(*)H coupling.The catalyst requires only 23.5 and 177.2 mV overpotentials to achieve current densities of 10 and 500 mA cm^(-2)in 1 M KOH.Notably,the PtCu/NC exhibits a~57%lower hydrogen evolution barrier than Pt/NC.Moreover,the PtCu/NC-based AEMWE operates for over 600 h at an industrially relevant current density of 500 mA cm^(-2).
基金Supported by the National Key Research and Development Program of China(2016YFB0303000)the National Natural Science Foundation of China(51803187)Zhejiang Provincial Natural Science Foundation of China(LQ18E030011)
文摘The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by numerical simulation and experiment.Falling film flow of high viscosity fluids was found to be steady on a vertical wavy wall in the presence of the large film thickness.The comparison between numerical simulation and experiment for the film thickness both in crest and trough of wavy wall showed good agreement.The simulation results of average residence time of falling film flow with different viscous fluids were also consistent with the experimental results.This work provides the initial insights of how to evaluate and optimize the falling film flow system of polymer fluid.
基金financially supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholarsthe State Education Ministry(No.1001603-C)+3 种基金"521 Talents Training Plan" in ZSTUthe National Natural Science Foundation of China(Nos.51373155 and 51133006)the Natural Science Foundation of Zhejiang Province(No.LY13B030009)the Innovative Program for Graduate Students of Zhejiang Sci-Tech University(No.2013YSPY15)
文摘The N-doped bismuth tungstate （BizWOt） photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samoles were characterized by X-ray diffraction, scanning electron microscopy, specific surface area, photocurrent analysis, and UV-Vis diffuse re- flectrance spectroscopy. The photocatalytic activity was evaluated by photocatalytic degradation of rhodamine B （RhB） solution under visible light irradiation. The photocatalytic mechanisms were analyzed by active species trapping experi- ments which revealed that the holes were the main active species of N-doped BizWO6 products in aqueous solution under visible light irradiation, rather than .OH and O-. With the assistance of H202, the photocatalytic activity for degradation of RhB could be further improved because H202 reacted with conduction band electrons to generate more hydroxyl radicals. KEY WORDS：
基金supported by National Natural Science Foundation of China (No.22006136)。
文摘The monoaminotrinitro iron phthalocyanine(FeMATNPc)is used to connect with isonicotinic acid(INA)for amide bonding and axial coordination to synthetic a unique catalyst FeMATNPc-INA,which is loaded in polyacrylonitrile(PAN)nanofibers by electrospinning.The introduction of INA destroys theπ-πconjugated stack structure in phthalocyanine molecules and exposes more active sites.The FeMATNPc-INA structure is characterized by X-ray photoelectron spectroscopy and UV-visible absorption spectrum,and the FeMATNPcINA/PAN structure is characterized by Fourier transform infrared spectroscopy and X-ray diffraction.The FeMATNPc-INA/PAN can effectively activate peroxymonosulfate(PMS)to eliminate carbamazepine(CBZ)within 40 minutes(PMS 1.5 mmol/L)in the dark.The effects of catalyst dosage,PMS concentration,pH and inorganic anion on the degradation of CBZ are investigated.It has been confirmed by electron paramagnetic resonance,gas chromatography–mass spectroscopy and free radical capture experiments that the catalytic system is degraded by·OH,SO4^(·-)and Fe(IV)=O are the major active species,the singlet oxygen(^(1)O_(2))is the secondary active species.The degradation process of CBZ is analyzed by ultra-high performance liquid chromatography-mass spectrometry and the aromatic compounds have been degraded to small molecular acids.
基金the National Natural Science Foundation of China(No.51703201)Zhejiang Provincial Natural Science Foundation of China(No.LQ17E030003)。
文摘Metal phthalocyanine has been extensively studied as a catalyst for degradation of carbamazepine(CBZ).However,metal phthalocyanine tends to undergo their own dimerization or polymerization,thereby reducing their activity points and affecting their catalytic properties.In this study,a catalytic system consisting of O-bridged iron perfluorophthalocyanine dimers(FePcF16-O-FePcF16),multi-walled carbon nanotubes(MWCNTs)and H2O_(2) was proposed.The results showed MWCNTs loaded with FePcF16-O-FePcF16 can achieve excellent degradation of CBZ with smaller dosages of FePcF16-O-FePcF16 and H2O_(2),and milder reaction temperatures.In addition,the results of experiments revealed the reaction mechanism of non-hydroxyl radicals.The highly oxidized high-valent iron-oxo(Fe(IV)=O)species was the main reactive species in the FePcF16-O-FePcF16/MWCNTs/H2O_(2) system.It is noteworthy that MWCNTs can improve the dispersion of FePcF16-O-FePcF16,contributing to the production of highly oxidized Fe(IV)=O.Then,the pathway of CBZ oxidative degradation was speculated,and the study results also provide new ideas for metal phthalocyanine-loaded carbon materials to degrade emerging pollutants.
基金the National Natural Science Foundation of China(52171199)for the financial support.
文摘Fe single-atom catalysts(Fe-SACs)have been extensively studied as a highly efficient electrocatalyst toward the oxygen reduction reaction(ORR).Nonetheless,they suffer from stability issue induced by dissolution of Fe metal center and the OH^(−)blocking.Herein,a surface molecular engineering strategy is developed by usingβ-cyclodextrins(CDs)as a localized molecular encapsulation.The CD-modified Fe-SAC(Fe-SNC-β-CD)shows obviously improved activity toward the ORR with 0.90 V,4.10 and 4.09 mA cm^(-2)for E_(1/2),J_(0)and Jk0.9,respectively.Meanwhile,the Fe-SNC-β-CD shows the excellent long-term stability against aggressive stress and the poisoning.It is confirmed through electrochemical investigation that modification ofβ-CD can,on one hand,regulate the atomic Fe coordination chemistry through the interaction between the CD and FeN_(x) moiety,while on the other mitigate the strong adsorption of OH^(−)and function as protective barrier against the poisoning molecules leading to enhanced ORR activity and stability for the Fe-SACs.The molecular encapsulation strategy demonstrates the uniqueness of post-pyrolysis surface molecular engineering for the design of single-atom catalyst.
基金financially supported by the ‘‘511 Talents Training Plan’’ in ZSTU,the National Natural Science Foundation of China (Nos.51133006 and 51373155)the Natural Science Foundation of Zhejiang Province(No.LY13B030009)
文摘Square and labyrinth-like titanium dioxide particles were successfully synthesized by a simple hydrothermal method with assistant of halloysite nanotubes. The morphology and microstructure of as-prepared photo-catalysts were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The photo-catalytic activity of as-prepared catalysts was evaluated by degradation of organic pollutants（Rhodamine B, methylene blue and methanol） under UV light irradiation.
基金financially supported by the National Natural Science Foundation of China(Nos.U180413,11904084,and U2004212)Center for Outstanding Overseas Scientists(No.GZS2023007).
文摘Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ultrathin carbon shell supported FePc molecule electrocatalysts(FePc/TA-ONG-N),featuring with a direct oxygen bridging between FePc and carbon substrate,were designed and synthesized.The direct connection with oxygen atom on carbon substrate,certified by the Fourier transform infrared spectroscopy(FTIR)and extended X-ray absorption fine structure(EXAFS),can remarkably enhance the interaction and facilitate electron transfer from Fe,leading to an improved activity by reducing adsorption strength of intermediate species through lowering the d-band center position.The resultant half-wave potential of 0.902 V together with a Tafel slope of 23.64 mV·dec^(−1)is superior to Pt/C and control samples.Such catalyst holds a promise as air-cathode electrocatalyst in Zn-air battery with excellent operation stability exceeding 80 h.The density functional theory(DFT)calculations and molecular dynamic simulations unveiled that the O-bridge can effectively stabilize the FePc molecule and function as electron buffer to donate/gain electrons to/from Fe atom during the adsorption of oxygenates.The current findings are insightful for developing molecular catalysts with high performance through substrate engineering and axial coordination.
基金supported by the National Natural Science Foundation of China(NSFC),Basic Sciences Center Program(Extreme Light Field Manufacturing,No.52488301)and NSFC General Program(No.52475425)the National Key R&D Program of China(No.2022YFB4601300)Aeronautical Science Fund(No.3030021252404).
文摘Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron spectroscopy(APXPS)emerges as an emerging photon-in-electron-out technique in in-situ/operando analysis by bridging the pressure-gap between conventional ultra-high vacuum(UHV)and near ambient or even close to operating conditions,rendering the advancement of XPS from a UHV-based technique to a versatile and powerful tool that enables the specific probe of numerous events taking place at the gas–solid,liquid–solid and liquid–gas nanoscale interfaces which are critical to nanocatalysis research.For example,APXPS probes information on catalytically active phase and reaction kinetics in nanocatalytic processes;details inside the electric double-layer at an electrolyte/electrode interface can now be accessed;more efficient nanocatalyst design can be achieved and energy transfer venues can be optimized.Here,we aim to critically review the recent advances in instrumentation and the probe of the gas–solid,liquid–solid,and gas–liquid nanoscale interfaces using APXPS-based methodologies,followed by putting forward an outlook of development of APXPS as a rising in-situ/operando analytical means in surface science,nanocatalysis,nanoscience materials science.
基金supported by the National Natural Science Foundation of China(No.22375019)Postdoctoral Fellowship Program of CPSF under Grant Number GZC20252673.
文摘The electrocatalytic C-N coupling reaction as a green synthesis approach for C-N bond synthesis via electrochemical processes with catalytic assistance.However,inefficient reactant adsorption onto the catalyst surface,competing side reactions,and the complexity and diversity of reaction pathways hinder its widespread application.Atomically dispersed catalysts(ADCs),as an emerging class of catalytic materials,possess precisely defined active sites,high catalytic activity,and enhanced selectivity,thereby enabling efficient electrocatalytic C-N coupling to address these challenges.This review discusses current reaction pathways for converting small molecules(CO_(2)as the carbon source,N_(2),NO_(2)^(-),NO_(3)^(-)as the nitrogen source)into high-value organic nitrogen compounds(urea,amides,oximes,and amino acids)utilizing ADCs.It specifically focuses on the critical steps within electrocatalytic C-N coupling facilitated by these catalysts,encompassing reactant adsorption,transformation and selective hydrogenation of C-/N-intermediates,and the C-N coupling reaction itself.Based on these key steps,design principles for ADCs are proposed.Finally,the synthesis strategies for ADCs-vacancy engineering,confinement strategies,and alloying-are examined,alongside the mechanisms by which they enhance catalytic activity and selectivity.
基金supported by the National Key R&D Program of China(Nos.2018YFA0702003 and 2016YFA0202801)the National Natural Science Foundation of China(Nos.21890383,21671117,21871159,and 21901135)+2 种基金the National Postdoctoral Program for Innovative Talents,the Shuimu Tsinghua Scholar,Science and Technology Key Project of Guangdong Province of China(No.2020B010188002)Beijing Municipal Science&Technology Commission(No.Z191100007219003)We thank the BL14W1 station in Shanghai Synchrotron Radiation Facility(SSRF)and 1W1B station for XAFS measurement in Beijing Synchrotron Radiation Facility(BSRF).
文摘Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to finely regulate their doping types and clarify their effect on the catalytic property of such catalysts.Herein,we report that the N-doping type in CN can be dominated as pyrrolic-N and pyridinic-N respectively through compounding with different metal oxides.It is found that the proportion of distinct doped N species in CN depends on the acidity and basicity of compounded metal oxide host.Owing to the coordination by pyrrolic-N,the SA Cu catalyst displays an enhanced activity(two-fold)for transfer hydrogenation of quinoline to access the valuable molecule tetrahydroquinoline with a good selectivity(99%)under mild conditions.The higher electron density of SA Cu species induced by the predominate pyrrolic-N coordination benefits the hydrogen transfer process and reduces the energy barrier of the hydrogenation pathway,which accounts for the improved catalytic effeciency.
基金supported by the National Key R&D Program of China (2017YFA0208300)the National Natural Science Foundation of China (21522107, 21671180, 21521091, 21390393, U1463202, and 21522305)
文摘Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber-Bosch process which accounts for 1.4% of the annual energy consumption. In this study, atomically dispersed Au_1 catalyst is synthesized and applied in electrochemical synthesis of ammonia under ambient conditions. A high NH＋4 Faradaic efficiency of 11.1 % achieved by our Au_1 catalyst surpasses most of reported catalysts under comparable conditions. Benefiting from efficient atom utilization, an NH＋4 yield rate of 1,305 μg h-1 mg-1Au has been reached, which is roughly 22.5 times as high as that by sup- ported Au nanoparticles. We also demonstrate that by employing our Au_1 catalyst, NH＋4 can be electro- chemically produced directly from N_2 and H_2 with an energy utilization rate of 4.02 mmol kJ-1. Our study provides a possibility of replacing the Haber-Bosch process with environmentally benign and energy-efficient electrochemical strategies.
基金the National Natural Science Foundation of China(Nos.21804319,21971002)the Natural Science Foundation of Anhui province(Nos.1908085QB45 and 2008085QB81)the Education Departm ent of Anhui Province Foundation(No.KJ2019A0503).We thank the BL14W1 station in Shanghai Synchrotron Radiation Facility(SSRF)and 1W1B station for XAFS measurement in Beijing Synchrotron Radiation Facility(BSRF).The calculations in this paper have been done on the supercomputing system of the National Supercomputing Center in Changsha.
文摘The demand for high-performance non-precious-metal electrocatalysts to replace the noble metal-based catalysts for oxygen reduction reaction(ORR)is intensively increasing.Herein,single-atomic copper sites supported on N-doped three-dimensional hierarchically porous carbon catalyst(Cu_(1)/NC)was prepared by coordination pyrolysis strategy.Remarkably,the Cu_(1)/NC-900 catalyst not only exhibits excellent ORR performance with a half-wave potential of 0.894 V(vs.RHE)in alkaline media,outperforming those of commercial Pt/C(0.851 V)and Cu nanoparticles anchored on N-doped porous carbon(CuNPs/NC-900),but also demonstrates high stability and methanol tolerance.Moreover,the Cu_(1)/NC-900 based Zn-air battery exhibits higher power density,rechargeability and cyclic stability than the one based on Pt/C.Both experimental and theoretical investigations demonstrated that the excellent performance of the as-obtained Cu_(1)/NC-900 could be attributed to the synergistic effect between copper coordinated by three N atoms active sites and the neighbouring carbon defect,resulting in elevated Cu d-band centers of Cu atoms and facilitating intermediate desorption for ORR process.This study may lead towards the development of highly efficient non-noble metal catalysts for applications in electrochemical energy conversion.
基金This work was supported by the National Key R&D Program of China(No.2018YFA0702003)the National Natural Science Foundation of China(No.21890383,21971137)Beijing Municipal Science&Technology Commission(No.Z191100007219003)。
文摘Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,directly anchoring metal single atoms on three-dimensional(3D)macro support,which is promising to achieve the heterogenization of homogeneous catalysis,remains a challenge and a blank in this field.Herein,we successfully fabricate metal single atoms(Pd,Pt,Ru,Au)on porous carbon nitride/reduced graphene oxide(C3N4/rGO)foam as highly efficient catalysts with convenient recyclability.C3N4/rGO foam features two-dimensional microstructures with abundant N chelating sites for the stabilization of metal single atoms and vertically-aligned hierarchical mesostructure that benefits the mass diffusion.The obtained Pdi/C3N4/rGO monolith catalyst exhibits much enhanced activity over its nanoparticle counterpart for Suzuki-Miyaura reaction.Moreover,the Pdi/C3N4/rGO monolith catalyst can be readily assembled in a flow reactor to achieve the highly efficient continuous production of 4-nitro-1,1'-biphenyl through Suzuki-Miyaura coupling.
基金This work was financially supported by the projects of National Natural Science Foundation of China(82003991,82101844,and 82304953)Natural Science Foundation of Jiangsu Province(BK20230744,China)+1 种基金Jiangsu Specially Appointed Professorship Foundation(013038021001,China)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22-2045 and KYCX23-2038,China).
文摘Aberrant tumor blood vessels are prone to propel the malignant progression of tumors,and targeting abnormal metabolism of tumor endothelial cells emerges as a promising option to achieve vascular normalization and antagonize tumor progression.Herein,we demonstrated that salvianic acid A(SAA)played a pivotal role in contributing to vascular normalization in the tumor-bearing mice,thereby improving delivery and effectiveness of the chemotherapeutic agent.SAA was capable of inhibiting glycolysis and strengthening endothelial junctions in the human umbilical vein endothelial cells(HUVECs)exposed to hypoxia.Mechanistically,SAA was inclined to directly bind to the glycolytic enzyme PKM2,leading to a dramatic decrease in endothelial glycolysis.More importantly,SAA improved the endothelial integrity via activating theβ-Catenin/Claudin-5 signaling axis in a PKM2-dependent manner.Our findings suggest that SAA may serve as a potent agent for inducing tumor vascular normalization.
基金the National Key R&D Program of China(2018YFA0702003)the National Natural Science Foundation of China(21890383,21671117,21871159 and21901135)the Science and Technology Key Project of Guangdong Province of China(2020B010188002)。
文摘The design of non-noble metal heterogeneous catalyst with superior performance for selective hydrogenation or transfer hydrogenation of nitroarenes to amines is significant but challenging.Herein,a single-atom Fe supported by nitrogen-doped carbon(Fe_(1)/N-C)catalyst is reported.The Fe_(1)/N-C sample shows superior performances for the selective hydrogenation and transfer hydrogenation of nitrobenzene to aniline at different temperatures.Density functional theory(DFT)calculations show that the superior catalytic activity for the selective hydrogenation at lower temperatures could be attributed to the effective activation of the reactant and intermediates by the Fe_(1)/N-C.Moreover,the excellent performance of Fe_(1)/N-C for the selective transfer hydrogenation could be attributed to that the reaction energy barrier for dehydrogenation of isopropanol can be overcome by elevated temperatures.
基金The authors thank the National Natural Science Foundation of China(No.U1804140)China Postdoctoral Science Foundation(No.2021M702939)for support.
文摘Transition metal sulfides with homogeneous multi-metallic elements promise high catalytic performance for water electrolysis owing to the unique structure and highly tailorable electrochemical property.Most existing synthetic routes require high temperature to ensure the uniform mixing of various elements,making the synthesis highly challenging.Here,for the first-time novel carbon fiber supported high-entropy Co-Zn-Cd-Cu-Mn sulfide(CoZnCdCuMnS@CF)nanoarrays are fabricated by the mild cation exchange strategy.Benefiting from the synergistic effect among multiple metals and the strong interfacial bonding between high-entropy Co-Zn-Cd-Cu-Mn sulfide nanoarrays and the carbon fiber support,CoZnCdCuMnS@CF exhibits superior catalytic activity and stability toward overall water splitting in alkaline medium.Impressively,CoZnCdCuMnS@CF only needs low overpotentials of 173 and 220 mV to reach the current density of 10 mA•cm^(−2),with excellent durability for over 70 and 113 h for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)respectively.More importantly,the bifunctional electrode(CoZnCdCuMnS@CF||CoZnCdCuMnS@CF)for overall water splitting can deliver a small cell voltage of 1.63 V to afford 10 mA•cm^(−2) and exhibit outstanding stability of negligible decay after 73 h continuous operation.This work provides a viable synthesis route toward advanced high-entropy materials with great potential applications.
基金This work was supported by the National Key R&D Program of China(2018YFA0702003)the National Natural Science Foundation of China(21890383,21671117,21871159 and 21901135).
文摘The rational design of efficient single-atomic(SA)catalysts is essential and highly desirable but impeded by the lack of sufficient acknowledge between structure and property.To this end,it is critical to clarify the effect of the coordination structure of active metal centers on the catalytic activities for the design of such catalysts.Here,we report that different coordination structures of SA Pt catalysts can dramatically influence their activities for anti-Markovnikov hydroboration of alkenes.Compared with the other two coordination structures(Pt-N4 and Pt-O2),the SA Pt species coordinated with three O atoms(Pt-O3)display the highest turnover number value of 3288 for the hydroboration reaction to access the important alkylboronic esters.Density functional theory calculations reveal that a superior catalytic activity can be expected for alkene hydroboration over the three O coordinated Pt species due to the lowest reaction energy(ΔG)limiting step from the reaction phase diagram.
