Enhancing the catalytic activity of catalysts is a core objective in their design and synthesis processes,and the accessibility of active sites is one of the crucial factors determining catalyst activity.Polyoxometala...Enhancing the catalytic activity of catalysts is a core objective in their design and synthesis processes,and the accessibility of active sites is one of the crucial factors determining catalyst activity.Polyoxometalate-based metal-organic complexes(POMOCs)with well-defined structures,which combine the advantages of POMs and MOCs,may offer the possibility to construct catalysts with highly accessible active sites.In this study,a series of POMOCs were successfully designed and synthesized using different POM templates,including[CoII1.5(L)1.5(PMo12O40)(H_(2)O)4]·3H_(2)O(Co-PMo12),[CoII1.5(L)1.5(PW12O40)(H_(2)O)4]·3H_(2)O(Co-PW12),[CoII2(L)2-(SiW12O40)(H_(2)O)4]·11H_(2)O(Co-SiW12),and H[CoII2.5(L)3-(P2W18O62)(H_(2)O)8]·10H_(2)O(Co-P2W18),which were characterized by Fourier transform infrared spectroscopy,powder X-ray diffraction,and single crystal X-ray diffraction.The differences in catalytic activity among the four POMOCs for olefin epoxidation were attributed to the distinct accessibility of Co(II)sites upon thermal activation.Among them,Co-P2W18 achieved a remarkable 99%yield of 1,2-epoxycyclooctane within 3 h at room temperature using O_(2)as the oxidant,owing to its highly accessible unsaturated Co(II)sites.Co-P2W18 exhibits significantly superior catalytic activity for the cyclooctene epoxidation reaction compared to most reported catalysts.Additionally,the reaction mechanism was investigated using density functional theory.展开更多
A new POM-based coordination polymer,[Cl_(2)Cu^(Ⅰ)_(11)(trz)_(8)][H_(3)SiW_(12)O_(40)](1),was successfully obtained under hydrothermal reaction.The compound was characterized by single-crystal X-ray diffraction,TGana...A new POM-based coordination polymer,[Cl_(2)Cu^(Ⅰ)_(11)(trz)_(8)][H_(3)SiW_(12)O_(40)](1),was successfully obtained under hydrothermal reaction.The compound was characterized by single-crystal X-ray diffraction,TGanalyses,IR spectra and PXRD analysis.Compound 1 shows extreme stability and outstanding catalytic activity to the degradation of organic dye pollutant.展开更多
Hollow structures are significant for shortening diffusion path and promoting active center exposure.Single-crystalline hollow polyoxometalate-based metal-organic frameworks(POM@MOFs)with increased adsorption performa...Hollow structures are significant for shortening diffusion path and promoting active center exposure.Single-crystalline hollow polyoxometalate-based metal-organic frameworks(POM@MOFs)with increased adsorption performance and catalytic activity were synthesized through a straightforward pseudo-homoepitaxial growth strategy within only 1.5 min.The strategy ingeniously exploits favorable characteristics of well-matched lattice/structure but acid stability difference between MOF and POM@MOF to construct a pseudo-homoepitaxial structure.Specifically,the MOF single crystals are used as seeds to perform epitaxial growth of the lattice/structure-matched POM@MOF under appropriate conditions.Interestingly,the MOF seeds collapse spontaneously during epitaxial growth,affording regular hollow POM@MOF single crystals.Because the acid stability of the POM@MOF is much higher than that of the MOF,it is speculated that the hollow structure formation may be related to the acid released from the epitaxial POM@MOF growth.And the pseudo-homoepitaxial POM@MOF growth strategy based on structural matching but stability difference avoids additional template removal process in conventional hollow MOF preparation and ensures hollow single crystal construction.展开更多
Metal organic frameworks have been employed as high-performance layered double hydroxide(LDH)composite supercapacitor electrode materials but have shown unsatisfactory redox ability and stability.Herein,a host-vip C...Metal organic frameworks have been employed as high-performance layered double hydroxide(LDH)composite supercapacitor electrode materials but have shown unsatisfactory redox ability and stability.Herein,a host-vip CuMo-based polyoxomet-alate-based metal organic framework(POMOF)with copious electrochemically active sites and strong electrochemical redox activi-ties has been effectively coupled with POM-incorporated CoNi-LDH to develop a nanocomposite(NENU-5@CoNi-LDH)by a simple solvothermal method.The designed electrode shows a high specific capacity of 333.61 mAh·g^(-1) at 1 A·g^(-1).In addition,the novel hy-brid symmetric supercapacitor NENU-5@CoNi-LDH/active carbon(AC)demonstrated a high energy density of 80.8 Wh·kg^(-1) at a power density of 750.7 W·kg^(-1).Interestingly,the nanocomposite of NENU-5@CoNi-LDH exhibits an outstanding capacitance reten-tion of 79%after 5000 charge-discharge cycles at 10 A·g^(-1).This work provides a new strategy and will be the backbone for future energy storage research.展开更多
Three novel polyoxovanadate-based metal-organic frameworks(POV-MOFs),[Co_(2)(1,4-dtzb)_(3)]{V_(4)O_(12)}(V-Co-MOF_(1),1,4-dtzb=1,4-di(4H-1,2,4-triazol-4-yl)benzene],[Co_(3)(1,3-dtzb)_(2)][{V_(6)O_(18)}(V-Co-MOF_(2),1,...Three novel polyoxovanadate-based metal-organic frameworks(POV-MOFs),[Co_(2)(1,4-dtzb)_(3)]{V_(4)O_(12)}(V-Co-MOF_(1),1,4-dtzb=1,4-di(4H-1,2,4-triazol-4-yl)benzene],[Co_(3)(1,3-dtzb)_(2)][{V_(6)O_(18)}(V-Co-MOF_(2),1,3-dtzb=1,3-di(4H-1,2,4-triazol-4-yl)benzene],[Co_(4)(4,4’-bdtzb)_(2)]{V_(8)O_(24)}(V-Co-MOF_(3),4,4’-bdtzb=4,4’-(1,1’-biphenyl)-4,4’-diylbis(4H-1,2,4-triazole)benzene]were facilely synthesized and structurally characterized.Single-crystal X-ray diffraction analysis indicates that all the POV-MOFs possess open V sites lined on POV clusters of{V_(4)O_(12)}/{V_(6)O_(18)}/{V_(8)O_(24)}that uniformly distribute on the robust three-dimensional frameworks.This unique structural feature allows them to show high performance for sulfidesulfoxide transformation when performing the reaction in MeOH at 50℃ for 45 min using H_(2)O_(2) as green oxidant.Notably,V-Co-MOF1 exhibited the highest catalytic efficiency,with a conversion>99% and selectivity up to 97% for a series of sulfide substrates.Control reaction demonstrated the catalytically active centers are the open V sites while the MOF skeleton constructed from Co^(2+)and ligands also contributes to enhance the conversion and selectivity via synergistic effect.Furthermore,V-Co-MOF1 can be used as a stable heterogeneous catalyst,and both the structural integrity and catalytic performance were well reserved after five cycles,demonstrating their great potential for advanced catalytic oxidation.展开更多
Cluster-based functional materials have made remarkable progress owing to their wonderful structures and distinctive physicochemical performances,one of on-going advancements of which is basically driven by synthetic ...Cluster-based functional materials have made remarkable progress owing to their wonderful structures and distinctive physicochemical performances,one of on-going advancements of which is basically driven by synthetic chemistry of exploring and constructing novel nanosized gigantic polyoxometalate(POM)aggregates.In this article,an unprecedented nanoscale hexameric arsenotungstate aggregate Na_(9)K_(16)H_(4)[Er_(0.5)K_(0.5)(H_(2)O)_(7)][Er_(5)W10O_(2)6(H_(2)O)_(14)][B-α-AsW_(9)O_(33)]_(6)·102H_(2)O(1)has been synthesized by the combined synthetic strategy of simultaneously using the arsenotungstate precursor and simple tungstate material in a highly acidic aqueous solution.The{[Er_(5)W_(10)O_(26)(H_(2)O)_(14)][B-α-AsW_(9)O_(33)]6}31-polyanion in 1 consists of an intriguing dumbbell-shaped pentadeca-nuclear W-Er heterometal{Er_(5)W10O_(2)6(H_(2)O)_(14)}^(23+)cluster connecting six trilacunary[B-α-AsW_(9)O_(33)]^(9-)moieties,which has never been seen previously.Furthermore,through electropolymerization of 1 and pyrrole on the conductive substrate,a thickness-controllable and robust 1-PPY(PPY=polypyrrole)hybrid film was successfully prepared,which represents the first POM-PPY film assembled from high-nuclear lanthanide(Ln)encapsulated POM and PPY hitherto.The 1-PPY film-based electrochemical biosensor exhibits a favorable recognition performance for ochratoxin A in multiple media.This work not only provides a feasible combined synthetic strategy of the POM precursor and simple tungstate material for constructing complicated multi-Ln-inserted POM aggregates,but also offers a promising electrochemical platform constructed from POM-based conductive films for identifying trace biomolecules in complex environments.展开更多
基金financially supported by the National Natural Science Foundation of China(22271021,21971024,and 22201021)the Natural Science Foundation and Education Department of Liaoning Province(LJ232410167011)。
文摘Enhancing the catalytic activity of catalysts is a core objective in their design and synthesis processes,and the accessibility of active sites is one of the crucial factors determining catalyst activity.Polyoxometalate-based metal-organic complexes(POMOCs)with well-defined structures,which combine the advantages of POMs and MOCs,may offer the possibility to construct catalysts with highly accessible active sites.In this study,a series of POMOCs were successfully designed and synthesized using different POM templates,including[CoII1.5(L)1.5(PMo12O40)(H_(2)O)4]·3H_(2)O(Co-PMo12),[CoII1.5(L)1.5(PW12O40)(H_(2)O)4]·3H_(2)O(Co-PW12),[CoII2(L)2-(SiW12O40)(H_(2)O)4]·11H_(2)O(Co-SiW12),and H[CoII2.5(L)3-(P2W18O62)(H_(2)O)8]·10H_(2)O(Co-P2W18),which were characterized by Fourier transform infrared spectroscopy,powder X-ray diffraction,and single crystal X-ray diffraction.The differences in catalytic activity among the four POMOCs for olefin epoxidation were attributed to the distinct accessibility of Co(II)sites upon thermal activation.Among them,Co-P2W18 achieved a remarkable 99%yield of 1,2-epoxycyclooctane within 3 h at room temperature using O_(2)as the oxidant,owing to its highly accessible unsaturated Co(II)sites.Co-P2W18 exhibits significantly superior catalytic activity for the cyclooctene epoxidation reaction compared to most reported catalysts.Additionally,the reaction mechanism was investigated using density functional theory.
基金Supported by the Key Research Program of Frontier Science,CAS(QYZDJ-SSW-SLH033)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)the National Natural Science Foundation of China(21521061,21773247,21875252,52073286)。
文摘A new POM-based coordination polymer,[Cl_(2)Cu^(Ⅰ)_(11)(trz)_(8)][H_(3)SiW_(12)O_(40)](1),was successfully obtained under hydrothermal reaction.The compound was characterized by single-crystal X-ray diffraction,TGanalyses,IR spectra and PXRD analysis.Compound 1 shows extreme stability and outstanding catalytic activity to the degradation of organic dye pollutant.
基金supported by the National Natural Science Foundation of China (22172022,21872021,22071019,22171035,21901135)
文摘Hollow structures are significant for shortening diffusion path and promoting active center exposure.Single-crystalline hollow polyoxometalate-based metal-organic frameworks(POM@MOFs)with increased adsorption performance and catalytic activity were synthesized through a straightforward pseudo-homoepitaxial growth strategy within only 1.5 min.The strategy ingeniously exploits favorable characteristics of well-matched lattice/structure but acid stability difference between MOF and POM@MOF to construct a pseudo-homoepitaxial structure.Specifically,the MOF single crystals are used as seeds to perform epitaxial growth of the lattice/structure-matched POM@MOF under appropriate conditions.Interestingly,the MOF seeds collapse spontaneously during epitaxial growth,affording regular hollow POM@MOF single crystals.Because the acid stability of the POM@MOF is much higher than that of the MOF,it is speculated that the hollow structure formation may be related to the acid released from the epitaxial POM@MOF growth.And the pseudo-homoepitaxial POM@MOF growth strategy based on structural matching but stability difference avoids additional template removal process in conventional hollow MOF preparation and ensures hollow single crystal construction.
基金financially supported by the National Natural Science Foundation of China(22001156)the Youth Talent Fund of University Association for Science and Technology in Shaanxi,China(20210602)the Science Foundation of Science and Technology Department of Shaanxi Province(2021JQ-533).
文摘Metal organic frameworks have been employed as high-performance layered double hydroxide(LDH)composite supercapacitor electrode materials but have shown unsatisfactory redox ability and stability.Herein,a host-vip CuMo-based polyoxomet-alate-based metal organic framework(POMOF)with copious electrochemically active sites and strong electrochemical redox activi-ties has been effectively coupled with POM-incorporated CoNi-LDH to develop a nanocomposite(NENU-5@CoNi-LDH)by a simple solvothermal method.The designed electrode shows a high specific capacity of 333.61 mAh·g^(-1) at 1 A·g^(-1).In addition,the novel hy-brid symmetric supercapacitor NENU-5@CoNi-LDH/active carbon(AC)demonstrated a high energy density of 80.8 Wh·kg^(-1) at a power density of 750.7 W·kg^(-1).Interestingly,the nanocomposite of NENU-5@CoNi-LDH exhibits an outstanding capacitance reten-tion of 79%after 5000 charge-discharge cycles at 10 A·g^(-1).This work provides a new strategy and will be the backbone for future energy storage research.
基金supported by the National Natural Science Foundation of China(Nos.92161111,21901037,21901038)Shanghai Pujiang Program(No.19PJ1400200)+1 种基金the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher LearningInternational Cooperation Fund of Science and Technology Commission of Shanghai Municipality(No.21130750100)。
文摘Three novel polyoxovanadate-based metal-organic frameworks(POV-MOFs),[Co_(2)(1,4-dtzb)_(3)]{V_(4)O_(12)}(V-Co-MOF_(1),1,4-dtzb=1,4-di(4H-1,2,4-triazol-4-yl)benzene],[Co_(3)(1,3-dtzb)_(2)][{V_(6)O_(18)}(V-Co-MOF_(2),1,3-dtzb=1,3-di(4H-1,2,4-triazol-4-yl)benzene],[Co_(4)(4,4’-bdtzb)_(2)]{V_(8)O_(24)}(V-Co-MOF_(3),4,4’-bdtzb=4,4’-(1,1’-biphenyl)-4,4’-diylbis(4H-1,2,4-triazole)benzene]were facilely synthesized and structurally characterized.Single-crystal X-ray diffraction analysis indicates that all the POV-MOFs possess open V sites lined on POV clusters of{V_(4)O_(12)}/{V_(6)O_(18)}/{V_(8)O_(24)}that uniformly distribute on the robust three-dimensional frameworks.This unique structural feature allows them to show high performance for sulfidesulfoxide transformation when performing the reaction in MeOH at 50℃ for 45 min using H_(2)O_(2) as green oxidant.Notably,V-Co-MOF1 exhibited the highest catalytic efficiency,with a conversion>99% and selectivity up to 97% for a series of sulfide substrates.Control reaction demonstrated the catalytically active centers are the open V sites while the MOF skeleton constructed from Co^(2+)and ligands also contributes to enhance the conversion and selectivity via synergistic effect.Furthermore,V-Co-MOF1 can be used as a stable heterogeneous catalyst,and both the structural integrity and catalytic performance were well reserved after five cycles,demonstrating their great potential for advanced catalytic oxidation.
基金This work was supported by the National Natural Science Foundation of China(Nos.21871077,21671054,21771052,22071042,22171070,91122028,and 21831001)the Program for Innovation Teams in Science and Technology in Universities of Henan Province(No.20IRTSTHN004).
文摘Cluster-based functional materials have made remarkable progress owing to their wonderful structures and distinctive physicochemical performances,one of on-going advancements of which is basically driven by synthetic chemistry of exploring and constructing novel nanosized gigantic polyoxometalate(POM)aggregates.In this article,an unprecedented nanoscale hexameric arsenotungstate aggregate Na_(9)K_(16)H_(4)[Er_(0.5)K_(0.5)(H_(2)O)_(7)][Er_(5)W10O_(2)6(H_(2)O)_(14)][B-α-AsW_(9)O_(33)]_(6)·102H_(2)O(1)has been synthesized by the combined synthetic strategy of simultaneously using the arsenotungstate precursor and simple tungstate material in a highly acidic aqueous solution.The{[Er_(5)W_(10)O_(26)(H_(2)O)_(14)][B-α-AsW_(9)O_(33)]6}31-polyanion in 1 consists of an intriguing dumbbell-shaped pentadeca-nuclear W-Er heterometal{Er_(5)W10O_(2)6(H_(2)O)_(14)}^(23+)cluster connecting six trilacunary[B-α-AsW_(9)O_(33)]^(9-)moieties,which has never been seen previously.Furthermore,through electropolymerization of 1 and pyrrole on the conductive substrate,a thickness-controllable and robust 1-PPY(PPY=polypyrrole)hybrid film was successfully prepared,which represents the first POM-PPY film assembled from high-nuclear lanthanide(Ln)encapsulated POM and PPY hitherto.The 1-PPY film-based electrochemical biosensor exhibits a favorable recognition performance for ochratoxin A in multiple media.This work not only provides a feasible combined synthetic strategy of the POM precursor and simple tungstate material for constructing complicated multi-Ln-inserted POM aggregates,but also offers a promising electrochemical platform constructed from POM-based conductive films for identifying trace biomolecules in complex environments.
