Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modificat...Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modification methods.Constructing defects on the surface of catalytic materials can effectively modulate the coordination environment of the active sites,affecting and changing the electrons,geometry,and other important properties at the catalytic active sites,thus altering the catalytic activity of the catalysts.However,the conformational relationship between defects and catalytic activity remains to be clarified.This dissertation focuses on an overview of recent advances in defect engineering in environmental catalysis.Based on defining the classification of defects in catalytic materials,defect construction methods,and characterization techniques are summarized and discussed.Focusing on an overview of the characteristics of the role of defects in electrocatalytic,photocatalytic,and thermal catalytic reactions and the mechanism of catalytic reactions.An elaborate link is given between the reaction activity and the structure of catalyst defects.Finally,the existing challenges and possible future directions for the application of defect engineering in environmental catalysis are discussed,which are expected to guide the design and development of efficient environmental catalysts and mechanism studies.展开更多
MgH_(2)is a promising solid-state hydrogen storage material.However,its high thermodynamics and sluggish kinetics hinder its practical application.Catalytic strategy is effective in improving its kinetic performance.N...MgH_(2)is a promising solid-state hydrogen storage material.However,its high thermodynamics and sluggish kinetics hinder its practical application.Catalytic strategy is effective in improving its kinetic performance.Nevertheless,the highly efficient catalysts or additives are normally of low-yield in fabrication with high cost.In this work,a novel structural LaVO_(4)fabricated by a low-cost method of spraying dry followed by a calcination is used as a catalytic additive for the hydrogen storage of MgH_(2).With an optimized addition of LaVO_(4),the overall hydrogen storage performances of MgH_(2)are significantly improved.An onset dehydrogenation temperature of only 183℃is obtained after an initial activation of dehydrogenation and hydrogenation.The system can desorb 5.7 wt%H_(2)at 250℃within 10 min and maintains a dehydrogenation capacity of 5.0 wt%H_(2)after 50 cycles.It is found that LaVO_(4)is transferred to lanthanum hydride and metallic vanadium in the initial dehydrogenation process,the former acts as a highly effective catalyst for the hydrogen storage of MgH_(2)and the latter undergoes reversible hydrogenation and dehydrogenation in the subsequent cycles.The structural design of the catalyst and its scalable fabrication are highly valuable in realizing the practical application of catalytic strategy for the hydrogen storage of MgH_(2).展开更多
The dielectric loss of carbon materials is closely related to the microstructure and the degree of crystallization,and the microstructure modulation of electromagnetic wave absorbing carbon materials is the key to enh...The dielectric loss of carbon materials is closely related to the microstructure and the degree of crystallization,and the microstructure modulation of electromagnetic wave absorbing carbon materials is the key to enhancing absorption properties.In this work,a porous elastic Co@CNF-PDMS composite was prepared by freeze-drying and confined catalysis.The graphitization degree and conductivity loss of carbon nanofibers(CNFs)were regulated by heat treatment temperature and Co catalyst content.The construction of a heterointerface between Co and C enhances the interfacial polarization loss.The Co@CNF-PDMS composite with 4.5 mm achieves the minimum reflection loss(RLmin)of-81.0 dB at 9.9 GHz and RL no higher than-12.1 dB in the whole of the X-band.After applying a load of up to 40% strain and 100 cycles to Co@CNF-PDMS,the dielectric properties of the composite remain stable.With the increase of compression strain,the distribution density of the absorbent increases,and the CNF sheet layer extrusion contact forms a conductive path,which leads to the conductive loss increase,finally,the absorption band moves to a high frequency.The absorption band can be bi-directionally regulated by loading and strain with good stability,which provides a new strategy for the development of intelligent electromagnetic wave absorbing materials.展开更多
With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,off...With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.展开更多
Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strateg...Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strategy for the functionalization and conversion of C-H bonds of 1,4-naphthoquinones into C-N bonds,providing an effective route to synthesize 2-(N-substituted amino)-1,4-naphthoquinone with high yield under mild conditions.Additionally,the synergistic catalytic mechanism was investigated by 1H NMR titration experiments and LC-MS analysis,with experimental results sufficiently and consistently supporting the proposed mechanism of the catalytic cycle.展开更多
Catalysis is a cornerstone of modern chemistry,enabling the development of sustainable processes and the production of essential chemicals.However,a fundamental challenge in catalysis lies in understanding the nature ...Catalysis is a cornerstone of modern chemistry,enabling the development of sustainable processes and the production of essential chemicals.However,a fundamental challenge in catalysis lies in understanding the nature of the catalytic species and active centers,particularly the key mechanistic understanding of homogeneous and heterogeneous systems.This review describes the concept of“cocktail”-type catalysis,demonstrating that catalytic active species are not static but evolve through the interconversion of molecular complexes,clusters,and nanoparticles.By bridging homogeneous and heterogeneous catalysis,this paradigm challenges conventional mechanistic views and initiates discussions for a universal theory of catalysis.The findings highlight the importance of adaptive catalyst behavior,leading to more efficient,selective,and robust catalytic systems.The impact of the“cocktail”-type approach extends beyond fundamental research,offering practical applications in industrial catalysis,green chemistry,and synthetic methodologies.By embracing catalytic dynamics,new opportunities arise for designing next-generation catalysts that are both versatile and highly effective in diverse transformations.展开更多
Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, d...Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, diverse photocatalysts, including ruthenium(II), iridium(Ⅲ), and organic dyes, have been most commonly applied.展开更多
Porous molecular sieve catalysts,including aluminosilicate zeolites and silicoaluminophosphate(SAPO)molecular sieves,have found widespread use in heterogeneous catalysis and are expected to play a key role in advancin...Porous molecular sieve catalysts,including aluminosilicate zeolites and silicoaluminophosphate(SAPO)molecular sieves,have found widespread use in heterogeneous catalysis and are expected to play a key role in advancing carbon neutrality and sustainable development.Given the ubiquitous presence of water during catalyst synthesis,storage,and application,the interactions between water and molecular sieves as well as their consequent effects on frameworks and catalytic reactions have attracted considerable attention.These effects are inherently complex and highly dependent on various factors such as temperature,water phase,and partial pressure.In this review,we provide a comprehensive overview of the current understanding of water-molecular sieve interactions and their roles in catalysis,based on both experimental and theoretical calculation results.Special attention is paid to water-induced reversible and irreversible structural changes in aluminosilicate and SAPO frameworks at the atomic level,underscoring the dynamic and labile nature of these frameworks in water environments.The influence of water on catalytic performance and reaction kinetics in molecular sieve-catalyzed reactions is discussed from two perspectives:(1)its participation in reaction through hydrogen bonding interactions,such as competitive adsorption at active sites,stabilization of ground and transition states,and proton transfer bridge;(2)its role as a direct reactant forming new species via reactions with other vip molecules.Recent advancements in this area provide valuable insights for the rational design and optimization of catalysts for water-involved reactions.展开更多
Catalysis has made great contributions to the productivity of human society. Therefore, the pursuit of new catalysts and research on catalytic processes has never stopped. Continuous and in-depth catalysis research si...Catalysis has made great contributions to the productivity of human society. Therefore, the pursuit of new catalysts and research on catalytic processes has never stopped. Continuous and in-depth catalysis research significantly increases the complexity of dynamic systems and multivariate optimization, thus posing higher challenges to research methodologies. Recently, the significant advancement of generative artificial intelligence (AI) provides new opportunities for catalysis research. Different from traditional discriminative AI, this state-of-the-art technique generates new samples based on existing data and accumulated knowledge, which endows it with attractive potential for catalysis research — a field featuring a vast exploration space, diverse data types and complex mapping relationships. Generative AI can greatly enhance both the efficiency and innovation capacity of catalysis research, subsequently fostering new scientific paradigms. This perspective covers the basic introduction, unique advantages of this powerful tool, and presents cases of generative AI implemented in various catalysis researches, including catalyst design and optimization, characterization technique enhancement and guidance for new research paradigms. These examples highlight its exceptional efficiency and general applicability. We further discuss the practical challenges in implementation and future development perspectives, ultimately aiming to promote better applications of generative AI in catalysis.展开更多
OVERVIEW OF WYSS The World Young Scientist Summit(WYSS),co-hosted by the China Association for Science and Technology and the People's Government of Zhejiang Province,is centered on the theme"Converging the W...OVERVIEW OF WYSS The World Young Scientist Summit(WYSS),co-hosted by the China Association for Science and Technology and the People's Government of Zhejiang Province,is centered on the theme"Converging the World's Talents,Creating a Better Future."The event has been held annually for six consecutive years since its inception.In 2019,Chinese President Xi Jinping sent a congratulatory message to the first WYSS,emphasizing that"the future of science and technology is dependent on the young."The following year,United Nations Secretary-General António Guterres also sent a letter to the attending young scientists.展开更多
Environmental catalysis has been considered one of the important research topics.Some technologies(e.g.,photocatalysis and electrocatalysis)have been intensively developed with the advance of synthetic technologies of...Environmental catalysis has been considered one of the important research topics.Some technologies(e.g.,photocatalysis and electrocatalysis)have been intensively developed with the advance of synthetic technologies of catalytical materials.In 2019,we discussed the development trend of this field,and wrote a roadmap on this topic in Chinese Chemical Letters(30(2019)2065-2088).Nowadays,we discuss it again from a new viewpoint along this road.In this paper,several subtopics are discussed,e.g.,photocatalysis based on titanium dioxide,violet phosphorus,graphitic carbon and covalent organic frameworks,electrocatalysts based on carbon,metal-and covalent-organic framework.Finally,we hope that this roadmap can enrich the development of two-dimensional materials in environmental catalysis with novel understanding,and give useful inspiration to explore new catalysts for practical applications.展开更多
Traditional biodiesel production primarily uses methanol as the acyl acceptor,but its toxicity to lipase increases process complexity and operational difficulty elevate manufacturing costs.This study aimed to explore ...Traditional biodiesel production primarily uses methanol as the acyl acceptor,but its toxicity to lipase increases process complexity and operational difficulty elevate manufacturing costs.This study aimed to explore a new method for enzymatic synthesis of biodiesel with methyl methacrylate(MMA)as acyl acceptor.Meanwhile,a 1,3-position specific lipase Lipozyme RM IM was applied as biocatalyst,which enables simultaneous production of biodiesel(FAMEs)and methacrylate fatty acid glycerides(MFAGs)via specific sn-1,3 transesterification of MMA with triglyceride.Under the optimal reaction conditions:temperature of 50℃,molar ratio of 4:1 for MMA to triglyceride,enzyme dosage of 7.5%(mass),and an extra water addition of 0.5%(mass);triglyceride conversion rate of 97%,and FAMEs yield of 65%could be obtained.Simultaneously,the multistage short-path distillation and column chromatographic method were combined used for the separation of the mixed products.Finally,the purity of FAME,MFADG,DMFAG,and MMFAG were 98%,97.8%,95.3%,and 81.78%,respectively.In this new approach,MMA demonstrates lower toxicity to lipases,allowing for straightfo rward addition of all the substrates without complex addition process,and enhancing operational feasibility.Meanwhile,the by-products of MFAGs could be applied as monomers in varnishes and protective coatings,which increased the value of the products.Thus,this investigation providing an alternative way to produce biodiesel,and providing a new pathway for the sustainable development of biodiesel.展开更多
An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal an...An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal and NHC synergetic catalysis,which demonstrated a versatile three-component reaction pattern,thus enabling two C-C bonds forged regioselectively in the reaction.The important reaction intermediates were successfully captured and characterized by HRMS analysis,and the migrative insertion of allene to the Ph-Pd species was identified as the reaction rate-limiting step by kinetic experiments.展开更多
A binder-free Ru@NiMoS electrode was engineered by in situ growth of twodimensional NiMoS nanosheets on nickel foam.This process effectively promoted the electrostatic-driven aggregation of Ru(bpy)_(3)^(2+),harnessing...A binder-free Ru@NiMoS electrode was engineered by in situ growth of twodimensional NiMoS nanosheets on nickel foam.This process effectively promoted the electrostatic-driven aggregation of Ru(bpy)_(3)^(2+),harnessing the synergistic effect to enhance electrochemiluminescence(ECL)performance.The integration(Ru@NiMoS)achieved an impressive ECL efficiency of 70.1%,marking an impressive 36.9-fold enhancement over conventional Ru.Additionally,its ECL intensity was found to be remarkably 172.2 times greater than that of Ru.Within the Ru(bpy)_(3)^(2+)/TPA system,NiMoS emerged as a pivotal electrochemical catalyst,markedly boosting both the oxygen evolution reaction and the generation of reactive intermediates.Leveraging these distinctive properties,a highly efficient ECL sensor for lidocaine detection was developed.This sensor exhibited a linear response within the concentration range of 1 nM to 1μM and achieved a remarkably low detection limit of 0.22 nM,underlining its substantial potential for practical application.展开更多
Hydrogen,as a cheap,clean,and cost-effective secondary energy source,performs an essential role in optimizing today’s energy structure.Magnesium hydride(Mg H_(2))represents an attractive hydrogen carrier for storage ...Hydrogen,as a cheap,clean,and cost-effective secondary energy source,performs an essential role in optimizing today’s energy structure.Magnesium hydride(Mg H_(2))represents an attractive hydrogen carrier for storage and transportation,however,the kinetic behavior and operating temperature remain undesirable.In this work,a dual-phase multi-site alloy(Ms A)anchored on carbon substrates was designed,and its superior catalytic effects on the hydrogen storage properties of MgH_(2) were reported.Mechanism analysis identified that multi-site Fe Ni_(3)/Ni Cu nanoalloys synergistically served as intrinsic drivers for the striking de/hydrogenation performance of the MgH_(2)-Ms A systems.Concretely,the unique multi-metallic site structure attached to the surface of MgH_(2)provided substantial reversible channels and accessible active sites conducive to the adsorption,activation,and nucleation of H atoms.In addition,the coupling system formed by FeNi_(3) and NiCu dual-phase alloys further enhanced the reactivity between Mg/MgH_(2) and H atoms.Hence,the onset dehydrogenation temperature of Mg H_(2)+5 wt%Ms A was reduced to 195℃ and the hydrogen desorption apparent activation energy was reduced to 83.6 k J/mol.5.08 wt%H_(2) could be released at 250℃ in 20 min,reaching a high dehydrogenation rate of 0.254 wt%H_(2)/min,yet that for MgH_(2) at a higher temperature of 335℃ was only 0.145 wt%H_(2)/min.Then,the dehydrogenated Mg H_(2)-Ms A sample could absorb hydrogen from room temperature(30℃)and charge 3.93 wt%H_(2) at 100℃ within20 min under 3.0 MPa H_(2) pressure.Benefiting from carbon substrates,the 5 wt%Ms A doped-MgH_(2) could still maintain 6.36 wt%hydrogen capacity after 20 cycles.In conclusion,this work provides experimental rationale and new insights for the design of efficient catalysts for magnesium-based solid-state hydrogen storage materials.展开更多
Late-stage modification of complex molecules via site-selective hydrodefluorination is a challenging endeavor.The selective activation of carbon-fluorine(C-F) bonds in the presence of multiple C-F bonds is of importan...Late-stage modification of complex molecules via site-selective hydrodefluorination is a challenging endeavor.The selective activation of carbon-fluorine(C-F) bonds in the presence of multiple C-F bonds is of importance in organic synthesis and drug discovery.Herein,we describe the activation of C-F bonds via multiphoton photoredox catalysis to selectively produces a series of hydrodefluorinated compounds by simply tuning the reaction conditions.Moreover,this protocol was successfully applied to the late-stage functionalization of different drug-derivatives and the corresponding mono-,di-,and tri-defluorinated products were obtained in good to excellent yields.A detailed mechanistic investigation provides insight into the unprecedented hydrodefluorination pathway.展开更多
Lithium-sulfur(Li-S)chemistry reaction opens a new battery era with high energy density;meanwhile,multiple electrons migration leads to the complex phase transition of sulfur species.To manipulate the binding strength...Lithium-sulfur(Li-S)chemistry reaction opens a new battery era with high energy density;meanwhile,multiple electrons migration leads to the complex phase transition of sulfur species.To manipulate the binding strength of multiple key intermediates more efficiently,the bimetallic TiVC MXene is utilized to realize multi-dimensional catalysis.Based on the macroscopic three-dimensional(3D)structure using two-dimensional(2D)MXene architecture,electron conductivity and sulfur utilization are improved.Microscopically,Ti-V catalytic systems regulate multiple reaction intermediates through intermetallic synergies customized surface properties and atomic scale coordination,thereby improving electronic and ionic conductivity.In-situ Raman spectroscopy and electrochemical analysis show that the conversion rate of polysulfides was accelerated during the charge-discharge process.The Ti-V interaction exhibits unique catalytic activity and regulates multiple continuous processes of sulfur species phase transformation,which are essential for the excellent energy performance of Li-S batteries.This study not only clarifies the catalytic mechanism of Ti-V at different dimensions but also proposes a promising strategy for the design of advanced catalytic systems in energy storage technology.展开更多
The photoinduced ligand-to-metal charge transfer(LMCT)process has been extensively investigated,however,the recovery of photocatalysts has remained a persistent challenge in the field.In light of this issue,a novel ap...The photoinduced ligand-to-metal charge transfer(LMCT)process has been extensively investigated,however,the recovery of photocatalysts has remained a persistent challenge in the field.In light of this issue,a novel approach involving the development of iron-based ionic liquids as photocatalysts has been pursued for the first time,with the goal of simultaneously facilitating the LMCT process and addressing the issue of photocatalyst recovery.Remarkably,the iron-based ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate(C_(4)mim-Fe Cl_(4))demonstrates exceptional recyclability and stability for the photocatalytic hydroacylation of olefins.This study will pave the way for new approaches to photocatalytic organic synthesis using ionic liquids as recyclable photocatalysts.展开更多
As important natural and pharmaceutical motifs,the catalytic construction of structurally diverse 3,3-disubstituted oxindoles often requires elaborate synthetic efforts on optimizations.Herein,we developed a simple an...As important natural and pharmaceutical motifs,the catalytic construction of structurally diverse 3,3-disubstituted oxindoles often requires elaborate synthetic efforts on optimizations.Herein,we developed a simple and divergent approach for constructing reverse-prenylated and prenylated oxindoles launched by Ni catalysis with bulk chemical isoprene.Using C3-unsubstituted oxindoles as starting materials,mono reverse-prenylation was demonstrated in high chemo-and regioselectivities facilitated by the combination of Ni(0)and monodentate phosphine ligand.Using the obtained reverse-prenylated oxindoles as versatile synthon,substitutions at the pseudobenzylic position with various electrophiles created vicinal quaternary centers in a concise way.With the help of additives(PPh3 and NaH),air could be directly used as green oxidant to construct prenylated and reverse-prenylatedα-hydroxy-oxindoles divergently from the same substrates.In situ esterification of prenylatedα-hydroxy-oxindoles allowed subsequent Friedel-Crafts substitutions with diverse nucleophiles to deliver prenyl substituted dimeric or spiro-oxindoles.This protocol provides a divergent synthetic approach for the construction of highly functionalized 3,3-disubstituted oxindoles,which have been otherwise difficult to access in a unified approach.展开更多
In the context of the global pursuit of sustainable energy,dual-atom catalysts(DACs)have attracted widespread attention due to their unique structural and excellent catalytic performance.Unlike the single-atom catalys...In the context of the global pursuit of sustainable energy,dual-atom catalysts(DACs)have attracted widespread attention due to their unique structural and excellent catalytic performance.Unlike the single-atom catalysts,DACs possess two active metal centers,exhibiting intriguing synergistic effects that significantly enhance their efficiency in various electrochemical reactions.This comprehensive review provides an overview of the recent advances in the field of dual-atom catalysts,focusing on their innovative preparation methods and strategies.It further delves into the intrinsic connections between structure and performance,discussing the applications of DACs in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,photocatalysis,carbon dioxide reduction reaction,and batteries.Lastly,a forward-looking perspective addresses the current challenges and outlines future directions.This review aims to deepen our understanding of DACs and stimulate further innovation in advanced catalysts for energy conversion systems.展开更多
基金supported by The National Key R&D Program of China(No.2021YFB3500700)National Natural Science Foundation of China(Nos.21677010 and 51808037)Special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04)。
文摘Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modification methods.Constructing defects on the surface of catalytic materials can effectively modulate the coordination environment of the active sites,affecting and changing the electrons,geometry,and other important properties at the catalytic active sites,thus altering the catalytic activity of the catalysts.However,the conformational relationship between defects and catalytic activity remains to be clarified.This dissertation focuses on an overview of recent advances in defect engineering in environmental catalysis.Based on defining the classification of defects in catalytic materials,defect construction methods,and characterization techniques are summarized and discussed.Focusing on an overview of the characteristics of the role of defects in electrocatalytic,photocatalytic,and thermal catalytic reactions and the mechanism of catalytic reactions.An elaborate link is given between the reaction activity and the structure of catalyst defects.Finally,the existing challenges and possible future directions for the application of defect engineering in environmental catalysis are discussed,which are expected to guide the design and development of efficient environmental catalysts and mechanism studies.
基金supported by the National Natural Science Foundation of PR China(Nos.52071287,52125104 and 52072342)Natural Science Foundation of Zhejiang Province,PR China(No.LZ23E010002).
文摘MgH_(2)is a promising solid-state hydrogen storage material.However,its high thermodynamics and sluggish kinetics hinder its practical application.Catalytic strategy is effective in improving its kinetic performance.Nevertheless,the highly efficient catalysts or additives are normally of low-yield in fabrication with high cost.In this work,a novel structural LaVO_(4)fabricated by a low-cost method of spraying dry followed by a calcination is used as a catalytic additive for the hydrogen storage of MgH_(2).With an optimized addition of LaVO_(4),the overall hydrogen storage performances of MgH_(2)are significantly improved.An onset dehydrogenation temperature of only 183℃is obtained after an initial activation of dehydrogenation and hydrogenation.The system can desorb 5.7 wt%H_(2)at 250℃within 10 min and maintains a dehydrogenation capacity of 5.0 wt%H_(2)after 50 cycles.It is found that LaVO_(4)is transferred to lanthanum hydride and metallic vanadium in the initial dehydrogenation process,the former acts as a highly effective catalyst for the hydrogen storage of MgH_(2)and the latter undergoes reversible hydrogenation and dehydrogenation in the subsequent cycles.The structural design of the catalyst and its scalable fabrication are highly valuable in realizing the practical application of catalytic strategy for the hydrogen storage of MgH_(2).
基金financially supported by the National Natural Science Foundation of China(No.52231007)the Natural Science Foundation of Shaanxi Province(No.2022JM-248)+1 种基金the Creative Research Foundation of the Science and Technology on Thermostructural Composite Materials Laboratorythe Doctoral Scientific Research Foundation of Shaanxi University of Science&Technology(No.BJ16-06).
文摘The dielectric loss of carbon materials is closely related to the microstructure and the degree of crystallization,and the microstructure modulation of electromagnetic wave absorbing carbon materials is the key to enhancing absorption properties.In this work,a porous elastic Co@CNF-PDMS composite was prepared by freeze-drying and confined catalysis.The graphitization degree and conductivity loss of carbon nanofibers(CNFs)were regulated by heat treatment temperature and Co catalyst content.The construction of a heterointerface between Co and C enhances the interfacial polarization loss.The Co@CNF-PDMS composite with 4.5 mm achieves the minimum reflection loss(RLmin)of-81.0 dB at 9.9 GHz and RL no higher than-12.1 dB in the whole of the X-band.After applying a load of up to 40% strain and 100 cycles to Co@CNF-PDMS,the dielectric properties of the composite remain stable.With the increase of compression strain,the distribution density of the absorbent increases,and the CNF sheet layer extrusion contact forms a conductive path,which leads to the conductive loss increase,finally,the absorption band moves to a high frequency.The absorption band can be bi-directionally regulated by loading and strain with good stability,which provides a new strategy for the development of intelligent electromagnetic wave absorbing materials.
基金financially supported by National Key R&D Program of China(2021YFB3500702)National Natural Science Foundation of China(Nos.21677010 and 51808037)Special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04).
文摘With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.
基金2024 Special Talent Introduction Projects of Key R&D Program of Ningxia Hui Autonomous Region(2024BEH04049)the 2024 Guyuan City Innovation-Driven Achievement Transformation Project(2024BGTYF01-47)2025 Ningxia Natural Science Foundation Program(2025AAC030624).
文摘Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strategy for the functionalization and conversion of C-H bonds of 1,4-naphthoquinones into C-N bonds,providing an effective route to synthesize 2-(N-substituted amino)-1,4-naphthoquinone with high yield under mild conditions.Additionally,the synergistic catalytic mechanism was investigated by 1H NMR titration experiments and LC-MS analysis,with experimental results sufficiently and consistently supporting the proposed mechanism of the catalytic cycle.
基金support by the Ministry of Science and Higher Education(075-15-2024-531)。
文摘Catalysis is a cornerstone of modern chemistry,enabling the development of sustainable processes and the production of essential chemicals.However,a fundamental challenge in catalysis lies in understanding the nature of the catalytic species and active centers,particularly the key mechanistic understanding of homogeneous and heterogeneous systems.This review describes the concept of“cocktail”-type catalysis,demonstrating that catalytic active species are not static but evolve through the interconversion of molecular complexes,clusters,and nanoparticles.By bridging homogeneous and heterogeneous catalysis,this paradigm challenges conventional mechanistic views and initiates discussions for a universal theory of catalysis.The findings highlight the importance of adaptive catalyst behavior,leading to more efficient,selective,and robust catalytic systems.The impact of the“cocktail”-type approach extends beyond fundamental research,offering practical applications in industrial catalysis,green chemistry,and synthetic methodologies.By embracing catalytic dynamics,new opportunities arise for designing next-generation catalysts that are both versatile and highly effective in diverse transformations.
文摘Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, diverse photocatalysts, including ruthenium(II), iridium(Ⅲ), and organic dyes, have been most commonly applied.
文摘Porous molecular sieve catalysts,including aluminosilicate zeolites and silicoaluminophosphate(SAPO)molecular sieves,have found widespread use in heterogeneous catalysis and are expected to play a key role in advancing carbon neutrality and sustainable development.Given the ubiquitous presence of water during catalyst synthesis,storage,and application,the interactions between water and molecular sieves as well as their consequent effects on frameworks and catalytic reactions have attracted considerable attention.These effects are inherently complex and highly dependent on various factors such as temperature,water phase,and partial pressure.In this review,we provide a comprehensive overview of the current understanding of water-molecular sieve interactions and their roles in catalysis,based on both experimental and theoretical calculation results.Special attention is paid to water-induced reversible and irreversible structural changes in aluminosilicate and SAPO frameworks at the atomic level,underscoring the dynamic and labile nature of these frameworks in water environments.The influence of water on catalytic performance and reaction kinetics in molecular sieve-catalyzed reactions is discussed from two perspectives:(1)its participation in reaction through hydrogen bonding interactions,such as competitive adsorption at active sites,stabilization of ground and transition states,and proton transfer bridge;(2)its role as a direct reactant forming new species via reactions with other vip molecules.Recent advancements in this area provide valuable insights for the rational design and optimization of catalysts for water-involved reactions.
基金supported by the National Natural Science Foundation of China(T2441001)the National Key Research&Development Program of China(2023YFB4104503).
文摘Catalysis has made great contributions to the productivity of human society. Therefore, the pursuit of new catalysts and research on catalytic processes has never stopped. Continuous and in-depth catalysis research significantly increases the complexity of dynamic systems and multivariate optimization, thus posing higher challenges to research methodologies. Recently, the significant advancement of generative artificial intelligence (AI) provides new opportunities for catalysis research. Different from traditional discriminative AI, this state-of-the-art technique generates new samples based on existing data and accumulated knowledge, which endows it with attractive potential for catalysis research — a field featuring a vast exploration space, diverse data types and complex mapping relationships. Generative AI can greatly enhance both the efficiency and innovation capacity of catalysis research, subsequently fostering new scientific paradigms. This perspective covers the basic introduction, unique advantages of this powerful tool, and presents cases of generative AI implemented in various catalysis researches, including catalyst design and optimization, characterization technique enhancement and guidance for new research paradigms. These examples highlight its exceptional efficiency and general applicability. We further discuss the practical challenges in implementation and future development perspectives, ultimately aiming to promote better applications of generative AI in catalysis.
文摘OVERVIEW OF WYSS The World Young Scientist Summit(WYSS),co-hosted by the China Association for Science and Technology and the People's Government of Zhejiang Province,is centered on the theme"Converging the World's Talents,Creating a Better Future."The event has been held annually for six consecutive years since its inception.In 2019,Chinese President Xi Jinping sent a congratulatory message to the first WYSS,emphasizing that"the future of science and technology is dependent on the young."The following year,United Nations Secretary-General António Guterres also sent a letter to the attending young scientists.
基金supported by the National Natural Science Foundation of China(Nos.52272290,21972030,52073119,and 52373210)the Natural Science Foundation of Jilin Province(No.20230101029JC)+1 种基金the Fundamental Research Program of Shanxi Province(No.202303021212159)the Monash University Malaysia–ASEAN grant(No.ASE-000010)。
文摘Environmental catalysis has been considered one of the important research topics.Some technologies(e.g.,photocatalysis and electrocatalysis)have been intensively developed with the advance of synthetic technologies of catalytical materials.In 2019,we discussed the development trend of this field,and wrote a roadmap on this topic in Chinese Chemical Letters(30(2019)2065-2088).Nowadays,we discuss it again from a new viewpoint along this road.In this paper,several subtopics are discussed,e.g.,photocatalysis based on titanium dioxide,violet phosphorus,graphitic carbon and covalent organic frameworks,electrocatalysts based on carbon,metal-and covalent-organic framework.Finally,we hope that this roadmap can enrich the development of two-dimensional materials in environmental catalysis with novel understanding,and give useful inspiration to explore new catalysts for practical applications.
文摘Traditional biodiesel production primarily uses methanol as the acyl acceptor,but its toxicity to lipase increases process complexity and operational difficulty elevate manufacturing costs.This study aimed to explore a new method for enzymatic synthesis of biodiesel with methyl methacrylate(MMA)as acyl acceptor.Meanwhile,a 1,3-position specific lipase Lipozyme RM IM was applied as biocatalyst,which enables simultaneous production of biodiesel(FAMEs)and methacrylate fatty acid glycerides(MFAGs)via specific sn-1,3 transesterification of MMA with triglyceride.Under the optimal reaction conditions:temperature of 50℃,molar ratio of 4:1 for MMA to triglyceride,enzyme dosage of 7.5%(mass),and an extra water addition of 0.5%(mass);triglyceride conversion rate of 97%,and FAMEs yield of 65%could be obtained.Simultaneously,the multistage short-path distillation and column chromatographic method were combined used for the separation of the mixed products.Finally,the purity of FAME,MFADG,DMFAG,and MMFAG were 98%,97.8%,95.3%,and 81.78%,respectively.In this new approach,MMA demonstrates lower toxicity to lipases,allowing for straightfo rward addition of all the substrates without complex addition process,and enhancing operational feasibility.Meanwhile,the by-products of MFAGs could be applied as monomers in varnishes and protective coatings,which increased the value of the products.Thus,this investigation providing an alternative way to produce biodiesel,and providing a new pathway for the sustainable development of biodiesel.
基金the National Natural Science Foundation of China(Nos.21831008,22025109,22101286)CAS Project for Young Scientists in Basic Research(No.YSBR-050)+1 种基金Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-201901)the State Key Laboratory of Fine Chemicals,Dalian University of Technology(No.KF2102)are gratefully acknowledged.
文摘An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal and NHC synergetic catalysis,which demonstrated a versatile three-component reaction pattern,thus enabling two C-C bonds forged regioselectively in the reaction.The important reaction intermediates were successfully captured and characterized by HRMS analysis,and the migrative insertion of allene to the Ph-Pd species was identified as the reaction rate-limiting step by kinetic experiments.
基金supported by the Natural Science Foun-dation of Jilin Province(20200201238JC)the Science and Technology Development Program of Jilin Province(20200404147YY)+2 种基金Shenzhen Key Laboratory of Func-tional Aggregate Materials(ZDSYS20211021111400001)the Science Technology Innovation Commission of Shenzhen Municipality(KQTD20210811090142053,JCYJ20220818103007014)Tianjin Key Medical Disci-pline(Specialty)Construction Project.Thanks to the AIE Institute(www.aietech.org.cn)for providing some tech-nical assistance.
文摘A binder-free Ru@NiMoS electrode was engineered by in situ growth of twodimensional NiMoS nanosheets on nickel foam.This process effectively promoted the electrostatic-driven aggregation of Ru(bpy)_(3)^(2+),harnessing the synergistic effect to enhance electrochemiluminescence(ECL)performance.The integration(Ru@NiMoS)achieved an impressive ECL efficiency of 70.1%,marking an impressive 36.9-fold enhancement over conventional Ru.Additionally,its ECL intensity was found to be remarkably 172.2 times greater than that of Ru.Within the Ru(bpy)_(3)^(2+)/TPA system,NiMoS emerged as a pivotal electrochemical catalyst,markedly boosting both the oxygen evolution reaction and the generation of reactive intermediates.Leveraging these distinctive properties,a highly efficient ECL sensor for lidocaine detection was developed.This sensor exhibited a linear response within the concentration range of 1 nM to 1μM and achieved a remarkably low detection limit of 0.22 nM,underlining its substantial potential for practical application.
基金financial supports from the National Key R&D Program of China(No.2020YFA0406204)the National Natural Science Foundation of China(No.51801078)。
文摘Hydrogen,as a cheap,clean,and cost-effective secondary energy source,performs an essential role in optimizing today’s energy structure.Magnesium hydride(Mg H_(2))represents an attractive hydrogen carrier for storage and transportation,however,the kinetic behavior and operating temperature remain undesirable.In this work,a dual-phase multi-site alloy(Ms A)anchored on carbon substrates was designed,and its superior catalytic effects on the hydrogen storage properties of MgH_(2) were reported.Mechanism analysis identified that multi-site Fe Ni_(3)/Ni Cu nanoalloys synergistically served as intrinsic drivers for the striking de/hydrogenation performance of the MgH_(2)-Ms A systems.Concretely,the unique multi-metallic site structure attached to the surface of MgH_(2)provided substantial reversible channels and accessible active sites conducive to the adsorption,activation,and nucleation of H atoms.In addition,the coupling system formed by FeNi_(3) and NiCu dual-phase alloys further enhanced the reactivity between Mg/MgH_(2) and H atoms.Hence,the onset dehydrogenation temperature of Mg H_(2)+5 wt%Ms A was reduced to 195℃ and the hydrogen desorption apparent activation energy was reduced to 83.6 k J/mol.5.08 wt%H_(2) could be released at 250℃ in 20 min,reaching a high dehydrogenation rate of 0.254 wt%H_(2)/min,yet that for MgH_(2) at a higher temperature of 335℃ was only 0.145 wt%H_(2)/min.Then,the dehydrogenated Mg H_(2)-Ms A sample could absorb hydrogen from room temperature(30℃)and charge 3.93 wt%H_(2) at 100℃ within20 min under 3.0 MPa H_(2) pressure.Benefiting from carbon substrates,the 5 wt%Ms A doped-MgH_(2) could still maintain 6.36 wt%hydrogen capacity after 20 cycles.In conclusion,this work provides experimental rationale and new insights for the design of efficient catalysts for magnesium-based solid-state hydrogen storage materials.
文摘Late-stage modification of complex molecules via site-selective hydrodefluorination is a challenging endeavor.The selective activation of carbon-fluorine(C-F) bonds in the presence of multiple C-F bonds is of importance in organic synthesis and drug discovery.Herein,we describe the activation of C-F bonds via multiphoton photoredox catalysis to selectively produces a series of hydrodefluorinated compounds by simply tuning the reaction conditions.Moreover,this protocol was successfully applied to the late-stage functionalization of different drug-derivatives and the corresponding mono-,di-,and tri-defluorinated products were obtained in good to excellent yields.A detailed mechanistic investigation provides insight into the unprecedented hydrodefluorination pathway.
基金the financial support provided by the National Natural Science Foundation of China(No.51932005)the Liaoning Revitalization Talents Program(No.XLYC1807175)+1 种基金the Development Plan of Science and Technology of Jilin Province,China(YDZJ202301ZYTS280)the Natural Science Foundation of Jilin Province(YDZJ202401316ZYTS)。
文摘Lithium-sulfur(Li-S)chemistry reaction opens a new battery era with high energy density;meanwhile,multiple electrons migration leads to the complex phase transition of sulfur species.To manipulate the binding strength of multiple key intermediates more efficiently,the bimetallic TiVC MXene is utilized to realize multi-dimensional catalysis.Based on the macroscopic three-dimensional(3D)structure using two-dimensional(2D)MXene architecture,electron conductivity and sulfur utilization are improved.Microscopically,Ti-V catalytic systems regulate multiple reaction intermediates through intermetallic synergies customized surface properties and atomic scale coordination,thereby improving electronic and ionic conductivity.In-situ Raman spectroscopy and electrochemical analysis show that the conversion rate of polysulfides was accelerated during the charge-discharge process.The Ti-V interaction exhibits unique catalytic activity and regulates multiple continuous processes of sulfur species phase transformation,which are essential for the excellent energy performance of Li-S batteries.This study not only clarifies the catalytic mechanism of Ti-V at different dimensions but also proposes a promising strategy for the design of advanced catalytic systems in energy storage technology.
基金financial support from the National Natural Science Foundation of China(Nos.22071222,22171249)the Natural Science Foundation of Henan Province(Nos.232300421363,242300420526)+2 种基金Key Research Projects of Universities in Henan Province(No.23A180010)Science&Technology Innovation Talents in Universities of Henan Province(No.23HASTIT003)Science and Technology Research and Development Plan Joint Fund of Henan Province(No.242301420006)。
文摘The photoinduced ligand-to-metal charge transfer(LMCT)process has been extensively investigated,however,the recovery of photocatalysts has remained a persistent challenge in the field.In light of this issue,a novel approach involving the development of iron-based ionic liquids as photocatalysts has been pursued for the first time,with the goal of simultaneously facilitating the LMCT process and addressing the issue of photocatalyst recovery.Remarkably,the iron-based ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate(C_(4)mim-Fe Cl_(4))demonstrates exceptional recyclability and stability for the photocatalytic hydroacylation of olefins.This study will pave the way for new approaches to photocatalytic organic synthesis using ionic liquids as recyclable photocatalysts.
文摘As important natural and pharmaceutical motifs,the catalytic construction of structurally diverse 3,3-disubstituted oxindoles often requires elaborate synthetic efforts on optimizations.Herein,we developed a simple and divergent approach for constructing reverse-prenylated and prenylated oxindoles launched by Ni catalysis with bulk chemical isoprene.Using C3-unsubstituted oxindoles as starting materials,mono reverse-prenylation was demonstrated in high chemo-and regioselectivities facilitated by the combination of Ni(0)and monodentate phosphine ligand.Using the obtained reverse-prenylated oxindoles as versatile synthon,substitutions at the pseudobenzylic position with various electrophiles created vicinal quaternary centers in a concise way.With the help of additives(PPh3 and NaH),air could be directly used as green oxidant to construct prenylated and reverse-prenylatedα-hydroxy-oxindoles divergently from the same substrates.In situ esterification of prenylatedα-hydroxy-oxindoles allowed subsequent Friedel-Crafts substitutions with diverse nucleophiles to deliver prenyl substituted dimeric or spiro-oxindoles.This protocol provides a divergent synthetic approach for the construction of highly functionalized 3,3-disubstituted oxindoles,which have been otherwise difficult to access in a unified approach.
基金supported by the China Postdoctoral Science Foundation(Nos.2021M700981,2022M711787,2021M691759 and 2021TQ0169)Shuimu Tsinghua Scholar program(No.2021SM071)Beijing Natural Science Foundation(No.2224103).
文摘In the context of the global pursuit of sustainable energy,dual-atom catalysts(DACs)have attracted widespread attention due to their unique structural and excellent catalytic performance.Unlike the single-atom catalysts,DACs possess two active metal centers,exhibiting intriguing synergistic effects that significantly enhance their efficiency in various electrochemical reactions.This comprehensive review provides an overview of the recent advances in the field of dual-atom catalysts,focusing on their innovative preparation methods and strategies.It further delves into the intrinsic connections between structure and performance,discussing the applications of DACs in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,photocatalysis,carbon dioxide reduction reaction,and batteries.Lastly,a forward-looking perspective addresses the current challenges and outlines future directions.This review aims to deepen our understanding of DACs and stimulate further innovation in advanced catalysts for energy conversion systems.
