The efficient and stable abatement of CO pollutant under ambient conditions is of great significance;however,it remains a formidable challenge.Herein,we report the versatile application of wet oxidation over Fe(OH)x s...The efficient and stable abatement of CO pollutant under ambient conditions is of great significance;however,it remains a formidable challenge.Herein,we report the versatile application of wet oxidation over Fe(OH)x supported subnanometer Pt group metal(PGM)catalysts for the complete removal of CO under ambient temperature and humidity conditions.Typically,the 1.8 wt%Rh/Fe(OH)x catalyst exhibited better durability during a^1400 min run for wet oxidation than for dry CO oxidation.Multiple characterization results including HR-TEM,H2-TPR,and in-situ DRIFTS suggested that Fe(OH)x,with good reducibility,promoted by the subnanometer Rh clusters,provided sites for the adsorption and reaction of O2 and H2 O to form OH species.Subsequently,these OH species reacted with the adsorbed CO on Rh sites with a considerably lower activation energy(9 kJ mol^-1)than that of dissociated 0 species(22 kJ mol^-1),thus rationalizing the outstanding performance of Rh/Fe(OH)x for wet oxidation.Extended experiments with other PGMs revealed a good generality for the application of wet oxidation in the efficient abatement of CO under humid conditions with Fe(OH)x as the support.展开更多
The industrial manufacture of ammonia(NH_(3))using Fe-based catalyst works under rigorous conditions.For the goal of carbon-neutrality,it is highly desired to develop advanced catalyst for NH_(3)synthesis at mild cond...The industrial manufacture of ammonia(NH_(3))using Fe-based catalyst works under rigorous conditions.For the goal of carbon-neutrality,it is highly desired to develop advanced catalyst for NH_(3)synthesis at mild conditions to reduce energy consumption and CO_(2)emissions.However,the main challenge of NH_(3)synthesis at mild conditions lies in the dissociation of steady N≡N triple bond.In this work,we report the design of subnanometer Ru clusters(0.8 nm)anchored on the hollow N-doped carbon spheres catalyst(Ru-SNCs),which effectively promotes the NH_(3)synthesis at mild conditions via an associative route.The NH_(3)synthesis rate over Ru-SNCs(0.49%(mass)Ru)reaches up to 11.7 mmol NH_(3)·(g cat)^(-1)·h^(-1) at 400℃ and 3 MPa,which is superior to that of 8.3 mmol NH_(3)·(g cat)^(-1)·h^(-1) over Ru nanoparticle catalyst(1.20%(mass)Ru).Various characterizations show that the N_(2)H_(4)species are the main intermediates for NH_(3)synthesis on Ru-SNCs catalyst.It demonstrates that Ru-SNCs catalyst can follow an associative route for N_(2)activation,which circumvents the direct dissociation of N_(2)and results in highly efficient NH_(3)synthesis at mild conditions.展开更多
The development of ultrasmall transition-metal dichalcogenide（such as MoS_2,MoSe_2） nanostructures is an efficient strategy to increase the active edge sites and overall performance for hydrogen evolution reaction. ...The development of ultrasmall transition-metal dichalcogenide（such as MoS_2,MoSe_2） nanostructures is an efficient strategy to increase the active edge sites and overall performance for hydrogen evolution reaction. Here,we report an in-situ tearing strategy to produce the carbon nanotube supported subnanometer ternary MoSeS（denoted as CNTs@NiSe@MoSeS） for efficient hydrogen evolution. Large（18.3 ± 1.1nm in length） multilayer MoS_2 sheets grown on Ni（OH）_2 thin film are torn into subnanometer（5.2 ± 0.7 nm in length） MoSeS via a subsequent selenization progress,along with the transformation of Ni（OH）_2 thin film into small Ni Se nanoplates. The resulting nanocomposite exhibits abundant active edge sites,outstanding 10,000-cycle stability and ultrahigh activity with a low overpotential of 189 mV at a high current density of 200 mA cm^（-2） toward hydrogen evolution.展开更多
As a mass transport media,water is an alternative of organic solvent applied in rechargeable batteries,due to its unique properties,including fast ionic migration,easy-processibility,economic/environmental friendlines...As a mass transport media,water is an alternative of organic solvent applied in rechargeable batteries,due to its unique properties,including fast ionic migration,easy-processibility,economic/environmental friendliness,and flame retardancy.However,due to the high activity of water molecules in aqueous electrolytes,the corrosion of metal anode,side reactions,and inferior metal electrodeposition behavior leads to unstable cycling performance,poor Coulombic efficiency(CE),and early-staged failure of batteries.Despite several attempts to regulate the activity of water,migration of ions is sacrificed,due to the limited methods to control the water states.Herein,we developed a subnanoscale confinement strategy based on a nacre-like structure to modulate the activity of water in the solid electrolytes.By tuning the ratio between the two-dimensional(2D)vermiculite and one-dimensional(1D)cellulose nanofibers(CNFs),the capillary size in the 1D/2D structure is altered to achieve a fast Zn^(2+)transport.Our dielectric relaxation and molecular dynamics studies indicate that the enhanced Zn^(2+)conductivity is attributed to the fast water relaxation in the precisely defined 1D/2D capillary.Taking advantage of the regulated activity of the confined water in 2D capillary,the composite vermiculite membrane can suppress the corrosion and side reactions between Zn electrode and water molecular,endowing a reversible Zn^(2+)stripping/plating behavior and a stable cycling performance for 900 h.Based on our confinement strategy to control the water states by 1D/2D structures,this work will open an avenue toward aqueous energy storage devices with excellent reversibility,high safety,and long-term stability.展开更多
In the attempt to reduce surface free energy of silica to improve interaction of silica with silver, silica was doped by different amounts of low surface energy lanthanum, La_2O_3, through impregnation. The doped and ...In the attempt to reduce surface free energy of silica to improve interaction of silica with silver, silica was doped by different amounts of low surface energy lanthanum, La_2O_3, through impregnation. The doped and undoped silica were used as supports for preparation of Na/Ag/Mo/La_2O_3-SiO_2 catalysts. Catalytic performances of the catalysts were evaluated in direct epoxidation of propylene(DPO) using molecular oxygen under atmospheric pressure and without adding hydrogen. Adding 5 wt%La to the Na/Ag/Mo/SiO_2 catalyst improves both the catalysts electivity in DPO and its stability over 20h of time-on-stream.The characterization results show that La_2O_3 species interact strongly with silver particles on the silica surface which result in significant improvement in the dispersion profile of silver and marked decrease in the size of silver nanoparticles(AgNPs). The estimated mean diameter of AgNPs is ca. 4.0 nm in Na/Ag/Mo/5 wt%La_2O_3-SiO_2, which is smaller than that(53.9 nm) found in Na/Ag/SiO_2. The presence of subnanometer AgNPs on Ag/La_2O_3-SiO_2 prior addition of MoO_3 and NaCl to the sample can enhance the mutual electronic synergism between Ag, MoO_3 and Na for selective production of propylene oxide.展开更多
A three-dimensional （3D） reconstruction of icosahedral virus is carried out by the icosahedral symmetry-adapted function （ISAF） method in spherical coordinates. In order to reduce the influence of noise, it is bet...A three-dimensional （3D） reconstruction of icosahedral virus is carried out by the icosahedral symmetry-adapted function （ISAF） method in spherical coordinates. In order to reduce the influence of noise, it is better to use the basis functions that have identical symmetry with the object reconstructed. It is verified that the ISAF method has stronger ability to reduce the influence of noise to grain the resolution better than that of the conventional method by the simulation of 3D reconstruction.展开更多
As one of the most advanced light source technologies,X-ray free-electron lasers(XFELs)generate radiation spanning from terahertz to X-ray wavelengths.1 These facilities deliver unprecedented spatiotemporal resolution...As one of the most advanced light source technologies,X-ray free-electron lasers(XFELs)generate radiation spanning from terahertz to X-ray wavelengths.1 These facilities deliver unprecedented spatiotemporal resolution at subnanometer spatial scales and femtosecond-to-attosecond temporal regimes,revolutionizing ultrafast studies in physics,chemistry,and biology.The unique capability of free-electron lasers(FELs)to produce intense,wavelength-tunable coherent pulses further enables investigations of matter under extreme conditions.展开更多
The solvolysis of ammonia borane(AB)and the hydrogenation of nitroarenes represent significant reactions for hydrogen generation and value-added chemical synthesis.The strategic engineering of the catalysts is imperat...The solvolysis of ammonia borane(AB)and the hydrogenation of nitroarenes represent significant reactions for hydrogen generation and value-added chemical synthesis.The strategic engineering of the catalysts is imperative for surmounting obstacles associated with their stability and catalytic efficiency.In this work,subnanometric bimetallic Pt–Pd clusters were encapsulated within silicalite-1(S-1)zeolites through a ligand-protected in-situ hydrothermal synthesis method.The synergetic effect of bimetallic composition and zeolite confinement markedly enhances the catalytic performance of representative Pt_(0.5)Pd_(0.5)@S-1-H catalyst,affording exceptional turnover frequency(TOF)values of 1,043 and 573 mol_(H_(2))mol_(metal)^(-1)min^(-1)for AB hydrolysis and methanolysis at ambient conditions,respectively,surpassing most of the state-of-the-art Pt-based catalysts.Kinetic and isotopic experiments reveal that the bimetallic catalytic system remarkably boosts the O-H cleavage of water,thereby facilitating the H_(2) production from AB hydrolysis.Remarkably,a conspicuous synergistic effect is demonstrated in the shape-selective tandem hydrogenation of nitroarenes,with the bimetallic catalyst facilitating both AB hydrolysis and nitroarene hydrogenation,giving a high TOF value of 1,260 h^(-1)under atmospheric pressure.This study not only demonstrates the effectiveness of bimetallic nanocatalysts encapsulated in zeolites for hydrogen production from chemical hydrogen storage materials,but also paves the way for the design of catalysts with multifunctional active sites capable of synergistically promoting tandem catalytic processes.展开更多
Herein,we present a facile strategy to prepare versatile aluminum oxide subnanometer nanosheets with oleic acid and stearic acid ligands(OA-Al SNSs and SA-Al SNSs,respectively).The size effect endows subnanosheets wit...Herein,we present a facile strategy to prepare versatile aluminum oxide subnanometer nanosheets with oleic acid and stearic acid ligands(OA-Al SNSs and SA-Al SNSs,respectively).The size effect endows subnanosheets with abundant acting sites,remarkable intermolecular interactions,and unique polymer-like properties,including flexibility,viscoelasticity,and sol-gel transitions,which is quite different from traditional inorganic materials.Consequently,subnanosheets could form freestanding organogels and OA-Al SNSs exhibit satisfying semisolidification of various solvents,making it an intriguing candidate for the safe storage and transportation of solvents.Furthermore,SA-Al SNSs exhibit excellent adhesive properties of high strength on diverse substrates,and it is easy to erase it without any damage,demonstrating the promising prospects in practical applications.展开更多
Atomic clusters of subnanometer scale and variable chemical composition offer great opportunities for rational design of functional nanomaterials.Among them,cage clusters doped with endohedral atom are particularly in...Atomic clusters of subnanometer scale and variable chemical composition offer great opportunities for rational design of functional nanomaterials.Among them,cage clusters doped with endohedral atom are particularly interesting owing to their enhanced stability and highly tunable physical and chemical properties.In this perspective,first we give a brief overview of the history of doped cage clusters and introduce the home-developed comprehensive genetic algorithm(CGA)for structure prediction of clusters.Then,we show a few examples of magnetic clusters and subnanometer catalysts based on doped cage clusters,which are computationally revealed or designed by the CGA code.Finally,we give an outlook for some future directions of cluster science.展开更多
基金supported by the National Natural Science Foundation of China(21576251,21676269,21808212,21878283)the Youth Innovation Promotion Association CAS(2017223)+5 种基金the “Strategic Priority Research Program” of the Chinese Academy of Sciences(XDB17020100)National Key Projects for Fundamental Research and Development of China(2016YFA0202801)China Postdoctoral Science Foundation(2019M652578)the Postdoctoral Sponsorship in Henan Province(1902015)Science and Technology Program of Henan Province(192102210034)Zhongyuan Postdoctoral Program for Innovation Talents~~
文摘The efficient and stable abatement of CO pollutant under ambient conditions is of great significance;however,it remains a formidable challenge.Herein,we report the versatile application of wet oxidation over Fe(OH)x supported subnanometer Pt group metal(PGM)catalysts for the complete removal of CO under ambient temperature and humidity conditions.Typically,the 1.8 wt%Rh/Fe(OH)x catalyst exhibited better durability during a^1400 min run for wet oxidation than for dry CO oxidation.Multiple characterization results including HR-TEM,H2-TPR,and in-situ DRIFTS suggested that Fe(OH)x,with good reducibility,promoted by the subnanometer Rh clusters,provided sites for the adsorption and reaction of O2 and H2 O to form OH species.Subsequently,these OH species reacted with the adsorbed CO on Rh sites with a considerably lower activation energy(9 kJ mol^-1)than that of dissociated 0 species(22 kJ mol^-1),thus rationalizing the outstanding performance of Rh/Fe(OH)x for wet oxidation.Extended experiments with other PGMs revealed a good generality for the application of wet oxidation in the efficient abatement of CO under humid conditions with Fe(OH)x as the support.
基金the Key Research&Development Program of National Natural Science Foundation of China(22038002)the National Natural Science Foundation of China(21972019,22108037)。
文摘The industrial manufacture of ammonia(NH_(3))using Fe-based catalyst works under rigorous conditions.For the goal of carbon-neutrality,it is highly desired to develop advanced catalyst for NH_(3)synthesis at mild conditions to reduce energy consumption and CO_(2)emissions.However,the main challenge of NH_(3)synthesis at mild conditions lies in the dissociation of steady N≡N triple bond.In this work,we report the design of subnanometer Ru clusters(0.8 nm)anchored on the hollow N-doped carbon spheres catalyst(Ru-SNCs),which effectively promotes the NH_(3)synthesis at mild conditions via an associative route.The NH_(3)synthesis rate over Ru-SNCs(0.49%(mass)Ru)reaches up to 11.7 mmol NH_(3)·(g cat)^(-1)·h^(-1) at 400℃ and 3 MPa,which is superior to that of 8.3 mmol NH_(3)·(g cat)^(-1)·h^(-1) over Ru nanoparticle catalyst(1.20%(mass)Ru).Various characterizations show that the N_(2)H_(4)species are the main intermediates for NH_(3)synthesis on Ru-SNCs catalyst.It demonstrates that Ru-SNCs catalyst can follow an associative route for N_(2)activation,which circumvents the direct dissociation of N_(2)and results in highly efficient NH_(3)synthesis at mild conditions.
基金supported in part by the National Natural Science Foundation of China (21475007 and 21675009)the Fundamental Research Funds for the Central Universities (buctrc201608 and buctrc201720)the support from the “Public Hatching Platform for Recruited Talents of Beijing University of Chemical Technology”
文摘The development of ultrasmall transition-metal dichalcogenide（such as MoS_2,MoSe_2） nanostructures is an efficient strategy to increase the active edge sites and overall performance for hydrogen evolution reaction. Here,we report an in-situ tearing strategy to produce the carbon nanotube supported subnanometer ternary MoSeS（denoted as CNTs@NiSe@MoSeS） for efficient hydrogen evolution. Large（18.3 ± 1.1nm in length） multilayer MoS_2 sheets grown on Ni（OH）_2 thin film are torn into subnanometer（5.2 ± 0.7 nm in length） MoSeS via a subsequent selenization progress,along with the transformation of Ni（OH）_2 thin film into small Ni Se nanoplates. The resulting nanocomposite exhibits abundant active edge sites,outstanding 10,000-cycle stability and ultrahigh activity with a low overpotential of 189 mV at a high current density of 200 mA cm^（-2） toward hydrogen evolution.
基金This work is financially supported by the National Key Research and Development Program(No.2021YFB3802500)National Natural Science Foundation of China(Nos.21972105 and 22278302)Haihe Laboratory of Sustainable Chemical Transformations,and 1000-Talent Program for Young Scientists.
文摘As a mass transport media,water is an alternative of organic solvent applied in rechargeable batteries,due to its unique properties,including fast ionic migration,easy-processibility,economic/environmental friendliness,and flame retardancy.However,due to the high activity of water molecules in aqueous electrolytes,the corrosion of metal anode,side reactions,and inferior metal electrodeposition behavior leads to unstable cycling performance,poor Coulombic efficiency(CE),and early-staged failure of batteries.Despite several attempts to regulate the activity of water,migration of ions is sacrificed,due to the limited methods to control the water states.Herein,we developed a subnanoscale confinement strategy based on a nacre-like structure to modulate the activity of water in the solid electrolytes.By tuning the ratio between the two-dimensional(2D)vermiculite and one-dimensional(1D)cellulose nanofibers(CNFs),the capillary size in the 1D/2D structure is altered to achieve a fast Zn^(2+)transport.Our dielectric relaxation and molecular dynamics studies indicate that the enhanced Zn^(2+)conductivity is attributed to the fast water relaxation in the precisely defined 1D/2D capillary.Taking advantage of the regulated activity of the confined water in 2D capillary,the composite vermiculite membrane can suppress the corrosion and side reactions between Zn electrode and water molecular,endowing a reversible Zn^(2+)stripping/plating behavior and a stable cycling performance for 900 h.Based on our confinement strategy to control the water states by 1D/2D structures,this work will open an avenue toward aqueous energy storage devices with excellent reversibility,high safety,and long-term stability.
基金Project supported by the KACST Strategic Technologies Research Grant(10-PET1103-06)
文摘In the attempt to reduce surface free energy of silica to improve interaction of silica with silver, silica was doped by different amounts of low surface energy lanthanum, La_2O_3, through impregnation. The doped and undoped silica were used as supports for preparation of Na/Ag/Mo/La_2O_3-SiO_2 catalysts. Catalytic performances of the catalysts were evaluated in direct epoxidation of propylene(DPO) using molecular oxygen under atmospheric pressure and without adding hydrogen. Adding 5 wt%La to the Na/Ag/Mo/SiO_2 catalyst improves both the catalysts electivity in DPO and its stability over 20h of time-on-stream.The characterization results show that La_2O_3 species interact strongly with silver particles on the silica surface which result in significant improvement in the dispersion profile of silver and marked decrease in the size of silver nanoparticles(AgNPs). The estimated mean diameter of AgNPs is ca. 4.0 nm in Na/Ag/Mo/5 wt%La_2O_3-SiO_2, which is smaller than that(53.9 nm) found in Na/Ag/SiO_2. The presence of subnanometer AgNPs on Ag/La_2O_3-SiO_2 prior addition of MoO_3 and NaCl to the sample can enhance the mutual electronic synergism between Ag, MoO_3 and Na for selective production of propylene oxide.
文摘A three-dimensional （3D） reconstruction of icosahedral virus is carried out by the icosahedral symmetry-adapted function （ISAF） method in spherical coordinates. In order to reduce the influence of noise, it is better to use the basis functions that have identical symmetry with the object reconstructed. It is verified that the ISAF method has stronger ability to reduce the influence of noise to grain the resolution better than that of the conventional method by the simulation of 3D reconstruction.
文摘As one of the most advanced light source technologies,X-ray free-electron lasers(XFELs)generate radiation spanning from terahertz to X-ray wavelengths.1 These facilities deliver unprecedented spatiotemporal resolution at subnanometer spatial scales and femtosecond-to-attosecond temporal regimes,revolutionizing ultrafast studies in physics,chemistry,and biology.The unique capability of free-electron lasers(FELs)to produce intense,wavelength-tunable coherent pulses further enables investigations of matter under extreme conditions.
基金supported by the National Key R&D Program of China(2022YFA1506000)the National Natural Science Foundation of China(22105110,22109110,22206094)+5 种基金the Natural Science Foundation of Shandong Province(ZR2021QB162,ZR2023YQ014)the Youth Innovation Team Project of Shandong Provincial Education Department(022KJ143)the Taishan Scholar Youth Expert Program in Shandong Province(tsqn202211122)the Gusu Innovation and Entrepreneurship Leading Talents Program(ZXL2022497)the Jiangsu Distinguished Professor Programthe Natural Science Foundation of Jiangsu Province(BK20210698)。
文摘The solvolysis of ammonia borane(AB)and the hydrogenation of nitroarenes represent significant reactions for hydrogen generation and value-added chemical synthesis.The strategic engineering of the catalysts is imperative for surmounting obstacles associated with their stability and catalytic efficiency.In this work,subnanometric bimetallic Pt–Pd clusters were encapsulated within silicalite-1(S-1)zeolites through a ligand-protected in-situ hydrothermal synthesis method.The synergetic effect of bimetallic composition and zeolite confinement markedly enhances the catalytic performance of representative Pt_(0.5)Pd_(0.5)@S-1-H catalyst,affording exceptional turnover frequency(TOF)values of 1,043 and 573 mol_(H_(2))mol_(metal)^(-1)min^(-1)for AB hydrolysis and methanolysis at ambient conditions,respectively,surpassing most of the state-of-the-art Pt-based catalysts.Kinetic and isotopic experiments reveal that the bimetallic catalytic system remarkably boosts the O-H cleavage of water,thereby facilitating the H_(2) production from AB hydrolysis.Remarkably,a conspicuous synergistic effect is demonstrated in the shape-selective tandem hydrogenation of nitroarenes,with the bimetallic catalyst facilitating both AB hydrolysis and nitroarene hydrogenation,giving a high TOF value of 1,260 h^(-1)under atmospheric pressure.This study not only demonstrates the effectiveness of bimetallic nanocatalysts encapsulated in zeolites for hydrogen production from chemical hydrogen storage materials,but also paves the way for the design of catalysts with multifunctional active sites capable of synergistically promoting tandem catalytic processes.
基金supported by NSFC(22241502,22035004,and 22250710677).
文摘Herein,we present a facile strategy to prepare versatile aluminum oxide subnanometer nanosheets with oleic acid and stearic acid ligands(OA-Al SNSs and SA-Al SNSs,respectively).The size effect endows subnanosheets with abundant acting sites,remarkable intermolecular interactions,and unique polymer-like properties,including flexibility,viscoelasticity,and sol-gel transitions,which is quite different from traditional inorganic materials.Consequently,subnanosheets could form freestanding organogels and OA-Al SNSs exhibit satisfying semisolidification of various solvents,making it an intriguing candidate for the safe storage and transportation of solvents.Furthermore,SA-Al SNSs exhibit excellent adhesive properties of high strength on diverse substrates,and it is easy to erase it without any damage,demonstrating the promising prospects in practical applications.
基金supported by the National Natural Science Foundation of China(91961204,11974068)the Fundamental Research Funds for the Central Universities of China(DUT20LAB110,DUT20LAB203)。
文摘Atomic clusters of subnanometer scale and variable chemical composition offer great opportunities for rational design of functional nanomaterials.Among them,cage clusters doped with endohedral atom are particularly interesting owing to their enhanced stability and highly tunable physical and chemical properties.In this perspective,first we give a brief overview of the history of doped cage clusters and introduce the home-developed comprehensive genetic algorithm(CGA)for structure prediction of clusters.Then,we show a few examples of magnetic clusters and subnanometer catalysts based on doped cage clusters,which are computationally revealed or designed by the CGA code.Finally,we give an outlook for some future directions of cluster science.
