We have previously shown the success of polyethylene glycol fusion repair of segmental-loss peripheral nerve injuries in rats using freshly harvested,viable peripheral nerve allografts that can conduct action potentia...We have previously shown the success of polyethylene glycol fusion repair of segmental-loss peripheral nerve injuries in rats using freshly harvested,viable peripheral nerve allografts that can conduct action potentials.Because clinical application of polyethylene glycol fusion with viable peripheral nerve allografts demands pre-transplant donor tissue storage,we developed a protocol for ex vivo storage of rat sciatic nerves as viable peripheral nerve allografts,preserving many axons for up to 5 days.The current study evaluated the in vivo use of these stored viable peripheral nerve allografts.We hypothesized that stored viable peripheral nerve allografts with viable axons would enable successful in vivo repair of segmental-loss peripheral nerve injuries via polyethylene glycol-fusion.Polyethylene glycol-fused viable peripheral nerve allografts were classified as successful if they produced significantly improved locomotor recovery,as evaluated by the sciatic functional index,within 8 weeks post-repair.Many Sprague-Dawley and Lewis rats with successfully polyethylene glycol-fused viable peripheral nerve allografts had significantly improved sciatic functional index scores beginning at 5 weeks post-operatively.There was no significant difference in the efficiency and extent of successful polyethylene glycol fusion between stored and freshly harvested viable peripheral nerve allografts.In contrast,rats with non-fused negative control viable peripheral nerve allografts showed no recovery by 8 weeks post-operatively.Additional confirmatory outcome measures included in vivo compound action potentials and assessments of axon morphometry.These results suggest that viable peripheral nerve allografts can be stored and later used for successful polyethylene glycol fusion repair of segmental-loss peripheral nerve injuries.展开更多
The Jellium closed-shell model,a cornerstone of cluster science,has long guided the design of superatoms by dictating electron-counting rules.However,its reliance on precise control of cluster composition and electron...The Jellium closed-shell model,a cornerstone of cluster science,has long guided the design of superatoms by dictating electron-counting rules.However,its reliance on precise control of cluster composition and electron shell occupancy presents significant experimental challenges.Here,we introduce a ligation strategy that circumvents these limitations by demonstrating that the adiabatic electron affinity(AEA) of aluminum-based clusters,whether with filled or partially filled electron shells,can be dramatically enhanced through the attachment of organic Lewis acid ligands.It was evidenced that the AEA of PAl12can be significantly increased by 2.17 e V after the ligation of two ligands,indicating a remarkable improvement in its electron-accepting ability.This approach yields superhalogen species,offering a versatile and practical means to tune the electronic properties of clusters while preserving their superatomic states,independent of shell occupancy.Remarkably,this ligand-induced modulation is not confined to naked clusters but also extends to nano-confined systems,hinting at its broader applicability.Given the indispensable role of ligands in cluster synthesis,this strategy holds promise for advancing the field of condensed-phase superatom synthesis,potentially complementing traditional electron-counting rules in a broader range of applications.展开更多
Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_...Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_(0.1)O_(3−δ)(BSCCFN)air electrode,based on Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF),is designed using a perovskite A-B-site ionic Lewis acid strength(ISA)polarization distribution strategy and is successfully applied in both oxygen-ion conducting solid oxide fuel cells(O-SOFCs)and proton-conducting reversible protonic ceramic cells(R-PCCs).When BSCCFN is used as the air electrode in O-SOFCs,a peak power density(PPD)of 1.45 W cm^(−2)is achieved at 650°C,whereas in R-PCCs,a PPD of 1.13 W cm^(−2)and a current density of−1.8 A cm^(−2)at 1.3 V are achieved at the same temperature and show stable reversibility over 100 h.Experimental measurements and theoretical calculations demonstrate that low-ISA Cs+doping accelerates the reaction kinetics of both oxygen ions and protons,while high-ISA Nb^(5+)doping enhances electrode stability.The synergistic effect of Cs^(+)and Nb^(5+)co-doping in the BSCCFN electrode lies in the ISA polarization distribution,which weakens the Co/Fe–O bond covalency,thereby promoting oxygen vacancy formation and facilitating the conduction of oxygen ions and protons.展开更多
Directional catalytic transformation of volatile organic compounds(VOCs)into value-added chemicals represents a more sustainable strategy than complete mineralization,as it simultaneously mitigates environmental pollu...Directional catalytic transformation of volatile organic compounds(VOCs)into value-added chemicals represents a more sustainable strategy than complete mineralization,as it simultaneously mitigates environmental pollution and reduces carbon emissions.The primary challenge in achieving multifunctional olefin production from alcohol-type VOCs is the lack of mechanistic clarity,which hinders the targeted synthesis of selective catalysts.Herein,we developed W-Ti hybrid metal oxide catalysts(WTiO_(x))with active Ti-O-W interfaces via a one-step hydrothermal synthesis and demonstrated their effectiveness for isopropanol conversion processes.Remarkably,WTiO_(x)-500 achieved 99.8%isopropanol conversion and 99.3% propylene yield at 140℃,significantly outperforming TiO_(2)(98.4% yield at 180℃)and WO_(3)(90.5% yield at 240℃).WTiO_(x)-500 also displayed higher thermal stability,with isopropanol conversion and propylene yield decreasing by 1.0%and 1.6% after 35 h on-stream reaction.Although impurities(e.g.,CO_(2),HCl,SO_(2))caused partial deactivation of WTiO_(x)-500,oxygen treatment regenerated the catalyst.A series of characterization techniques indicated that the controlled calcination temperature promoted the formation of an optimal Ti-O-Winterface in WTiO_(x)-500 through W substitution into the TiO_(2)lattice and WO_(3)-TiO_(2)surface interaction,where W species effectively tuned the electronic structure.This configuration endowed WTiO_(x)-500 with moderate acidity of BrФnsted(-OH)and Lewis(Ti^(4+)/W^(6+))acid sites,which synergistically facilitated charge transfer between isopropanol and catalyst,accelerated C-O bond cleavage during dehydration.This work provides mechanistic insights into isopropanol dehydration and demonstrates a potential approach for VOC valorization.展开更多
The high-efficiency conversion of biomass resources to biofuels has attracted widespread attention, and the active sites and synergistic effect of catalysts significantly impact their surface arrangement and electroni...The high-efficiency conversion of biomass resources to biofuels has attracted widespread attention, and the active sites and synergistic effect of catalysts significantly impact their surface arrangement and electronic structure. Here, a nickel-based transition metal carbide catalyst(Ni/TMC) with high Lewis acidity was prepared by self-assembly of transition metal carbide(TMC) and nickel, which exhibited excellent performance on synergistic hydrogenation and hydrogenolysis of 5-hydroxymethylfurfural(HMF) into liquid biofuel 2,5-dimethylfuran(DMF).Notably, Ni/WC with the highest Lewis acidity(4728.3 μmol g^(-1)) can achieve 100% conversion of HMF to 97.6% yield of DMF, with a turnover frequency of up to 46.5 h^(-1). The characterization results demonstrate that the rich Lewis acid sites yielded by the synergistic effect between Ni species and TMC are beneficial for the C=O hydrogenation and C–O cleavage, thereby accelerating the process of hydrodeoxygenation(HDO). Besides, a kinetic model for the HDO of HMF to DMF process has been established based on the experimental results, which elucidated a significant correlation between the measured and the predicted data(R^(2)> 0.97). Corresponding to the adsorption configuration of Ni/WC and substrate determined by in-situ FTIR characterization, this study provides a novel insight into the selective conversion of HMF process for functional biofuel and bio-chemicals.展开更多
High-capacity LiBH_(4)is a promising solid hydrogen storage material.However,the large electron cloud density between the B-H bonds in LiBH_(4)induces high dehydrogenation temperatures and sluggish dehydrogenation kin...High-capacity LiBH_(4)is a promising solid hydrogen storage material.However,the large electron cloud density between the B-H bonds in LiBH_(4)induces high dehydrogenation temperatures and sluggish dehydrogenation kinetics.To solve the above problems,it is proposed to enhance the hydrogen storage properties of LiBH_(4)through the synergistic effect of Brønsted and Lewis acid in Hβzeolite.Composite hydrogen storage systems with different mass ratios were prepared by simple ball-milling.At a LiBH_(4)-to-Hβmass ratio of 6:4,the 6LiBH_(4)-4Hβsystem released hydrogen at 190℃and achieved a hydrogen release capacity of 7.0 wt%H_(2)upon heating to 400℃.More importantly,the hydrogen release capacity of the system reached 6.02 wt%at 350℃under isothermal conditions after 100 min and 7.2 wt%at 400℃under isothermal conditions after 80 min,whereas the pristine LiBH_(4)only achieved 2.2 wt%.The improvement in hydrogen storage performance of the system was mainly attributed to two factors:(i)Lewis acid sites with acceptable electrons in the Hβweaken the electron density of B-H bonds in LiBH_(4),and(ii)the H+proton from the Brønsted acid sites and H−of LiBH_(4)undergo a H^(+)+H^(−)=H_(2)reaction.Theoretical calculations revealed that the Lewis and Brønsted acid sites in the Hβzeolite are conducive to the weakening of B-H bonds and that storage charge transfer occurs near the Lewis acid sites.The present work provides new insights into improving the hydrogen storage performance of LiBH_(4)by weakening the B-H bonds in the LiBH_(4).展开更多
This study employs density functional theory(DFT)calculations to systematically investigate the B‒H bond dissociation enthalpies(BDEs)of Lewis base‒borane complexes.A rigorous benchmark analysis identified theωB97XD/...This study employs density functional theory(DFT)calculations to systematically investigate the B‒H bond dissociation enthalpies(BDEs)of Lewis base‒borane complexes.A rigorous benchmark analysis identified theωB97XD/cc-pVTZ method as a reliable method for accurate prediction of B–H BDEs.An examination of more than 200 structurally diverse complexes across five major classes revealed that the type of Lewis base significantly influences the BDEs,with the order of amine–borane>phosphine–borane>N-heterocyclic carbene–borane>pyridine–borane.Solventstabilized boranes exhibit the broadest range of BDE values due to the diverse coordination modes of solvent molecules with borane.Further analysis revealed that the BDE values are synergistically affected by skeletal and substituent effects.Notably,a strong linear correlation(R^(2) up to 0.97)between the spin density of boryl radicals and BDEs,except for amine–boranes,provides a robust predictive model.This research enhances the fundamental understanding of B‒H bond dissociation properties in Lewis base–boranes and provides valuable insights for the development of new boron-based methodologies in organic synthesis.展开更多
基金National Institutes of Health(NIH)R01-NS128086 grant(to GDB and JSB)Lone Star Paralysis Foundation(to GDB).
文摘We have previously shown the success of polyethylene glycol fusion repair of segmental-loss peripheral nerve injuries in rats using freshly harvested,viable peripheral nerve allografts that can conduct action potentials.Because clinical application of polyethylene glycol fusion with viable peripheral nerve allografts demands pre-transplant donor tissue storage,we developed a protocol for ex vivo storage of rat sciatic nerves as viable peripheral nerve allografts,preserving many axons for up to 5 days.The current study evaluated the in vivo use of these stored viable peripheral nerve allografts.We hypothesized that stored viable peripheral nerve allografts with viable axons would enable successful in vivo repair of segmental-loss peripheral nerve injuries via polyethylene glycol-fusion.Polyethylene glycol-fused viable peripheral nerve allografts were classified as successful if they produced significantly improved locomotor recovery,as evaluated by the sciatic functional index,within 8 weeks post-repair.Many Sprague-Dawley and Lewis rats with successfully polyethylene glycol-fused viable peripheral nerve allografts had significantly improved sciatic functional index scores beginning at 5 weeks post-operatively.There was no significant difference in the efficiency and extent of successful polyethylene glycol fusion between stored and freshly harvested viable peripheral nerve allografts.In contrast,rats with non-fused negative control viable peripheral nerve allografts showed no recovery by 8 weeks post-operatively.Additional confirmatory outcome measures included in vivo compound action potentials and assessments of axon morphometry.These results suggest that viable peripheral nerve allografts can be stored and later used for successful polyethylene glycol fusion repair of segmental-loss peripheral nerve injuries.
基金supported by the National Natural Science Foundation of China (NSFC,Nos.12474274,92161101)the Innovation Project of Jinan Science and Technology Bureau (No.2021GXRC032)the Natural Science Foundation of Shandong Province (No.ZR2024MA091)。
文摘The Jellium closed-shell model,a cornerstone of cluster science,has long guided the design of superatoms by dictating electron-counting rules.However,its reliance on precise control of cluster composition and electron shell occupancy presents significant experimental challenges.Here,we introduce a ligation strategy that circumvents these limitations by demonstrating that the adiabatic electron affinity(AEA) of aluminum-based clusters,whether with filled or partially filled electron shells,can be dramatically enhanced through the attachment of organic Lewis acid ligands.It was evidenced that the AEA of PAl12can be significantly increased by 2.17 e V after the ligation of two ligands,indicating a remarkable improvement in its electron-accepting ability.This approach yields superhalogen species,offering a versatile and practical means to tune the electronic properties of clusters while preserving their superatomic states,independent of shell occupancy.Remarkably,this ligand-induced modulation is not confined to naked clusters but also extends to nano-confined systems,hinting at its broader applicability.Given the indispensable role of ligands in cluster synthesis,this strategy holds promise for advancing the field of condensed-phase superatom synthesis,potentially complementing traditional electron-counting rules in a broader range of applications.
基金funding from the National Natural Science Foundation of China (Award 91745203) supplemented by Central Universities’ Basic Research Funds.
文摘Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_(0.1)O_(3−δ)(BSCCFN)air electrode,based on Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF),is designed using a perovskite A-B-site ionic Lewis acid strength(ISA)polarization distribution strategy and is successfully applied in both oxygen-ion conducting solid oxide fuel cells(O-SOFCs)and proton-conducting reversible protonic ceramic cells(R-PCCs).When BSCCFN is used as the air electrode in O-SOFCs,a peak power density(PPD)of 1.45 W cm^(−2)is achieved at 650°C,whereas in R-PCCs,a PPD of 1.13 W cm^(−2)and a current density of−1.8 A cm^(−2)at 1.3 V are achieved at the same temperature and show stable reversibility over 100 h.Experimental measurements and theoretical calculations demonstrate that low-ISA Cs+doping accelerates the reaction kinetics of both oxygen ions and protons,while high-ISA Nb^(5+)doping enhances electrode stability.The synergistic effect of Cs^(+)and Nb^(5+)co-doping in the BSCCFN electrode lies in the ISA polarization distribution,which weakens the Co/Fe–O bond covalency,thereby promoting oxygen vacancy formation and facilitating the conduction of oxygen ions and protons.
基金supported by the National Natural Science Foundation of China(U23A20120 and 22425601)National Key R&D Program of China(2023YFB3810801)+2 种基金Natural Science Foundation of Hebei Province(B2021208033)Beijing Nova Program(20240484659)R&D Program of Beijing Municipal Education Commission(KZ202210005011).
文摘Directional catalytic transformation of volatile organic compounds(VOCs)into value-added chemicals represents a more sustainable strategy than complete mineralization,as it simultaneously mitigates environmental pollution and reduces carbon emissions.The primary challenge in achieving multifunctional olefin production from alcohol-type VOCs is the lack of mechanistic clarity,which hinders the targeted synthesis of selective catalysts.Herein,we developed W-Ti hybrid metal oxide catalysts(WTiO_(x))with active Ti-O-W interfaces via a one-step hydrothermal synthesis and demonstrated their effectiveness for isopropanol conversion processes.Remarkably,WTiO_(x)-500 achieved 99.8%isopropanol conversion and 99.3% propylene yield at 140℃,significantly outperforming TiO_(2)(98.4% yield at 180℃)and WO_(3)(90.5% yield at 240℃).WTiO_(x)-500 also displayed higher thermal stability,with isopropanol conversion and propylene yield decreasing by 1.0%and 1.6% after 35 h on-stream reaction.Although impurities(e.g.,CO_(2),HCl,SO_(2))caused partial deactivation of WTiO_(x)-500,oxygen treatment regenerated the catalyst.A series of characterization techniques indicated that the controlled calcination temperature promoted the formation of an optimal Ti-O-Winterface in WTiO_(x)-500 through W substitution into the TiO_(2)lattice and WO_(3)-TiO_(2)surface interaction,where W species effectively tuned the electronic structure.This configuration endowed WTiO_(x)-500 with moderate acidity of BrФnsted(-OH)and Lewis(Ti^(4+)/W^(6+))acid sites,which synergistically facilitated charge transfer between isopropanol and catalyst,accelerated C-O bond cleavage during dehydration.This work provides mechanistic insights into isopropanol dehydration and demonstrates a potential approach for VOC valorization.
基金Fundamental Research Foundation of CAF (CAFYBB2022QB001)National Nature Science Foundation of China for Excellent Young Scientists Fund (32222058)。
文摘The high-efficiency conversion of biomass resources to biofuels has attracted widespread attention, and the active sites and synergistic effect of catalysts significantly impact their surface arrangement and electronic structure. Here, a nickel-based transition metal carbide catalyst(Ni/TMC) with high Lewis acidity was prepared by self-assembly of transition metal carbide(TMC) and nickel, which exhibited excellent performance on synergistic hydrogenation and hydrogenolysis of 5-hydroxymethylfurfural(HMF) into liquid biofuel 2,5-dimethylfuran(DMF).Notably, Ni/WC with the highest Lewis acidity(4728.3 μmol g^(-1)) can achieve 100% conversion of HMF to 97.6% yield of DMF, with a turnover frequency of up to 46.5 h^(-1). The characterization results demonstrate that the rich Lewis acid sites yielded by the synergistic effect between Ni species and TMC are beneficial for the C=O hydrogenation and C–O cleavage, thereby accelerating the process of hydrodeoxygenation(HDO). Besides, a kinetic model for the HDO of HMF to DMF process has been established based on the experimental results, which elucidated a significant correlation between the measured and the predicted data(R^(2)> 0.97). Corresponding to the adsorption configuration of Ni/WC and substrate determined by in-situ FTIR characterization, this study provides a novel insight into the selective conversion of HMF process for functional biofuel and bio-chemicals.
基金supported by the National Natural Science Foundation of China(No.52201274)the Project of Education Department of Shanxi Province(No.22JK0419).
文摘High-capacity LiBH_(4)is a promising solid hydrogen storage material.However,the large electron cloud density between the B-H bonds in LiBH_(4)induces high dehydrogenation temperatures and sluggish dehydrogenation kinetics.To solve the above problems,it is proposed to enhance the hydrogen storage properties of LiBH_(4)through the synergistic effect of Brønsted and Lewis acid in Hβzeolite.Composite hydrogen storage systems with different mass ratios were prepared by simple ball-milling.At a LiBH_(4)-to-Hβmass ratio of 6:4,the 6LiBH_(4)-4Hβsystem released hydrogen at 190℃and achieved a hydrogen release capacity of 7.0 wt%H_(2)upon heating to 400℃.More importantly,the hydrogen release capacity of the system reached 6.02 wt%at 350℃under isothermal conditions after 100 min and 7.2 wt%at 400℃under isothermal conditions after 80 min,whereas the pristine LiBH_(4)only achieved 2.2 wt%.The improvement in hydrogen storage performance of the system was mainly attributed to two factors:(i)Lewis acid sites with acceptable electrons in the Hβweaken the electron density of B-H bonds in LiBH_(4),and(ii)the H+proton from the Brønsted acid sites and H−of LiBH_(4)undergo a H^(+)+H^(−)=H_(2)reaction.Theoretical calculations revealed that the Lewis and Brønsted acid sites in the Hβzeolite are conducive to the weakening of B-H bonds and that storage charge transfer occurs near the Lewis acid sites.The present work provides new insights into improving the hydrogen storage performance of LiBH_(4)by weakening the B-H bonds in the LiBH_(4).
基金supported by the USTC Research Funds of the Double First-Class Initiative(YD2060006004,YD2060002027)the National Natural Science Foundation of China(22325107,22171253,22293011).
文摘This study employs density functional theory(DFT)calculations to systematically investigate the B‒H bond dissociation enthalpies(BDEs)of Lewis base‒borane complexes.A rigorous benchmark analysis identified theωB97XD/cc-pVTZ method as a reliable method for accurate prediction of B–H BDEs.An examination of more than 200 structurally diverse complexes across five major classes revealed that the type of Lewis base significantly influences the BDEs,with the order of amine–borane>phosphine–borane>N-heterocyclic carbene–borane>pyridine–borane.Solventstabilized boranes exhibit the broadest range of BDE values due to the diverse coordination modes of solvent molecules with borane.Further analysis revealed that the BDE values are synergistically affected by skeletal and substituent effects.Notably,a strong linear correlation(R^(2) up to 0.97)between the spin density of boryl radicals and BDEs,except for amine–boranes,provides a robust predictive model.This research enhances the fundamental understanding of B‒H bond dissociation properties in Lewis base–boranes and provides valuable insights for the development of new boron-based methodologies in organic synthesis.
