Electrochemical water splitting has long been considered an effective energy conversion technology for trans-ferring intermittent renewable electricity into hydrogen fuel,and the exploration of cost-effective and high...Electrochemical water splitting has long been considered an effective energy conversion technology for trans-ferring intermittent renewable electricity into hydrogen fuel,and the exploration of cost-effective and high-performance electrocatalysts is crucial in making electrolyzed water technology commercially viable.Cobalt phosphide(Co-P)has emerged as a catalyst of high potential owing to its high catalytic activity and durability in water splitting.This paper systematically reviews the latest advances in the development of Co-P-based materials for use in water splitting.The essential effects of P in enhancing the catalytic performance of the hydrogen evolution reaction and oxygen evolution reaction are first outlined.Then,versatile synthesis techniques for Co-P electrocatalysts are summarized,followed by advanced strategies to enhance the electrocatalytic performance of Co-P materials,including heteroatom doping,composite construction,integration with well-conductive sub-strates,and structure control from the viewpoint of experiment.Along with these optimization strategies,the understanding of the inherent mechanism of enhanced catalytic performance is also discussed.Finally,some existing challenges in the development of highly active and stable Co-P-based materials are clarified,and pro-spective directions for prompting the wide commercialization of water electrolysis technology are proposed.展开更多
In this work,we synthesized MoS_(2)catalyst via one-step hydrothermal method,and systematically investigated the catalytic effect of MoS_(2)on the hydrogen storage properties of MgH_(2).The MgH_(2)-5MoS_(2)composite m...In this work,we synthesized MoS_(2)catalyst via one-step hydrothermal method,and systematically investigated the catalytic effect of MoS_(2)on the hydrogen storage properties of MgH_(2).The MgH_(2)-5MoS_(2)composite milled for 5 h starts to release hydrogen at 259℃.Furthermore,it can desorb 4.0 wt.%hydrogen within 20 min at 280℃,and absorb 4.5 wt.%hydrogen within 5 min at 200℃.Mo and MoS_(2)coexistedin the ball milled sample,whereas only Mo was kept in the sample after dehydrogenation and rehydrogenation,which greatly weakens theMg-H bonds and facilitates the dissociation of MgH_(2)on the surface of Mo(110).The comparative study show that the formed MgS has nocatalytic effect for MgH_(2).We believed that the evolution and the catalytic mechanism of MoS_(2)will provide the theoretical guidance for theapplication of metal sulfide in hydrogen storage materials.展开更多
In the conversion process of syngas-to-C_(2)species,the OH species are inevitably produced accompanying the production of key intermediates CH_(x)(x=1-3),traditionally,the function of surface OH species is generally a...In the conversion process of syngas-to-C_(2)species,the OH species are inevitably produced accompanying the production of key intermediates CH_(x)(x=1-3),traditionally,the function of surface OH species is generally accepted as the hydrogenating reactive species.This work for the first time proposed and confirmed the assisted catalytic mechanism of surface OH species that performed as the promoter for syngas-to-C_(2)species on Cu-based catalysts.DFT and microkinetic modeling results reveal that the produced OH species accompanying the intermediates CH_(x)production on the MCu(M=Co,Fe,Rh)catalysts can stably exist to form OH/MCu catalysts,on which the presence of surface OH species as the promoter not only presented better activity and selectivity toward CH_(x)(x=1-3)compared to MCu catalysts,but also significantly suppressed CH_(3)OH production,providing enough CH_(x)sources to favor the production of C_(2)hydrocarbons and oxygenates.Correspondingly,the electronic properties analysis revealed the essential relationship between the electronic feature of OH/MCu catalysts and catalytic performance,attributing to the unique electronic micro-environment of the catalysts under the interaction of surface OH species.This new mechanism is called as OH-assisted catalytic mechanism,which may be applied in the reaction systems related to the generation of OH species.展开更多
The alkylation mechanism catalyzed by an ionic liquid (as a Lewis acid) may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear....The alkylation mechanism catalyzed by an ionic liquid (as a Lewis acid) may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene (C 6 D 6) with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] +H + and [AlHCl 3 ] + +[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] + is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] + which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.展开更多
The interaction between the metal and the support of supported metal catalysts, which are widely used in industry, is the primary focus of the study of such catalysts. With the developing understanding of the metal–s...The interaction between the metal and the support of supported metal catalysts, which are widely used in industry, is the primary focus of the study of such catalysts. With the developing understanding of the metal–support interaction, the intrinsic factor that influences the catalytic performance has been determined to be the structure of interfacial sites. Layered double hydroxides(LDHs, a class of two-dimensional layered anion clay) possess several unique characteristics, such as the following:(1) tunable elemental component, homogeneous distribution of metal cations.(2) anchoring eff ect.(3) multiple layered structure for exfoliation or intercalation and special memory eff ect;and(4) internal/external confinement eff ects during topological transformation. Taking LDHs and their derivatives as precursors or supports shows superior advantages in designing interfacial active catalysts with tunable properties. Therefore, this review is mainly focused on constructing interfacial active catalysts by LDHs and revealing the interfacial eff ects(including electronic, geometric, and bifunctional eff ects) on the catalytic performance that will provide new perspectives and approaches for the development of heterogeneous catalysis.展开更多
Experiments on a ball milled mixture with a 1:1 molar ratio of LiNH2 and LiH with a small amount (1 mol %) of Ti^nano, TICl3 and TiO2^nano have revealed a superior catalytic effect on Li N H hydrogen storage materi...Experiments on a ball milled mixture with a 1:1 molar ratio of LiNH2 and LiH with a small amount (1 mol %) of Ti^nano, TICl3 and TiO2^nano have revealed a superior catalytic effect on Li N H hydrogen storage materials. In the x-ray diffraction profiles, no trace of Ti^nano, TICl3 and TiO2^nano was found in these doped composites, by which we deduced that Ti atoms enter LiNH2 by partial element substitution. A first-principles plane-wave pseudopotential method based on density functional theory has been used to investigate the catalytic effects of Ti catalysts on the dehydrogenating properties of LiNH2 system. The results show that Ti substitution can reduce the dehydrogenation reaction activation energy of LiNH2 and improve the dehydrogenating properties of LiNH2. Based on the analysis of the density of states and overlap populations for LiNH2 before and after Ti substitution, it was found that the stability of the system of LiNH2 is reduced, which originates from the increase of the valence electrons at the Fermi level (EF) and the decrease of the highest occupied molecular orbital (HOMO) lowest unoccupied molecular orbital (LUMO) gap (△EH-L) near EF. The catalytic effect of Ti on the dehydrogenating kinetics of LiNH2 may be attributed to the reduction of average populations between N-H per unit bond length (nm-1), which leads to the reduction of the chemical bond strength of NH.展开更多
Nanomaterials with enzyme-mimic(nanozyme) activity have garnered considerable attention as a potential alternative to natural enzymes, thanks to their low preparation cost, high activity, ease of preservation, and uni...Nanomaterials with enzyme-mimic(nanozyme) activity have garnered considerable attention as a potential alternative to natural enzymes, thanks to their low preparation cost, high activity, ease of preservation, and unique physicochemical properties. Vanadium(V) is a transition metal that integrates the benefits of valence-richness, low cost, and non-toxicity, making it a desirable candidate for developing a range of emerging nanozymes. In this review, we provide the first systematic summary of recent research progress on V-based nanozymes. First, we summarize the preparation of V-based nanozymes using both top-down and bottom-up synthesis methods. Next, we review the mechanism of V-based nanozymes that mimic the activity of various enzymes. We then discuss methods for regulating V-based nanozyme activity, including morphology, size, valence engineering, defect engineering, external triggering, and surface engineering. Afterward, we outline various biomedical applications, including therapeutic, anti-inflammatory, antibacterial, and biosensing. Finally, we prospect the challenges and countermeasures for V-based nanozymes based on their development. By summarizing recent research progress on V-based nanozymes, we hope to provide useful insights for researchers to further explore their potential applications and overcome their existing challenges.展开更多
Among various electrocatalysts,high entropy materials(HEMs)have attracted great attention due to the distinctive designing concept and unique properties with captivating electrocatalytic activity and stability.To date...Among various electrocatalysts,high entropy materials(HEMs)have attracted great attention due to the distinctive designing concept and unique properties with captivating electrocatalytic activity and stability.To date,HEMs have been a new family of advanced electrocatalysts in the research field of water electrolysis.In this work,the structural features and synthesis strategies of high entropy catalysts are reviewed,especially,their performances for catalyzing hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in water electrolysis are presented,in which the crucial roles of structure,composition,multisites synergy,and“four core effects”for enhancing catalytic activity,stability,and resistance of electrochemical corrosion are introduced.Besides,the design tactics,main challenges,and future prospects of HEM-based electrocatalysts for HER and OER are discussed.It is expected to provide valuable information for the development of low-cost efficient HEM-based electrocatalysts in the field of water electrolysis.展开更多
Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007,nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity,low cost,mild reaction...Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007,nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity,low cost,mild reaction conditions,good stability,and suitable for large-scale production.Recently,with the cross fusion of nanomedicine and nanocatalysis,nanozyme-based theranostic strategies attract great attention,since the enzymatic reactions can be triggered in the tumor microenvironment to achieve good curative effect with substrate specificity and low side effects.Thus,various nanozymes have been developed and used for tumor therapy.In this review,more than 270 research articles are discussed systematically to present progress in the past five years.First,the discovery and development of nanozymes are summarized.Second,classification and catalytic mechanism of nanozymes are discussed.Third,activity prediction and rational design of nanozymes are focused by highlighting the methods of density functional theory,machine learning,biomimetic and chemical design.Then,synergistic theranostic strategy of nanozymes are introduced.Finally,current challenges and future prospects of nanozymes used for tumor theranostic are outlined,including selectivity,biosafety,repeatability and stability,in-depth catalytic mechanism,predicting and evaluating activities.展开更多
Epigenetic modifications alter chromatin structures and consequently affect transcription and cellular functions.Major epigenetic markers include DNA methylation and histone acetylation and methylation.The modificatio...Epigenetic modifications alter chromatin structures and consequently affect transcription and cellular functions.Major epigenetic markers include DNA methylation and histone acetylation and methylation.The modifications are reversible and are achieved in aid of relative enzymes.Much effort has been directed at the understanding of the chemical mechanisms of individual catalytic reactions,which can serve as a foundation for inhibitor development.Among the many methods deployed,structural studies have proven the most effective for understanding enzyme-mediated modifications and have provided support for the development of lead-candidate drug inhibitors.This review briefly summarizes the existing knowledge on the catalytic mechanisms of the major epigenetic modification enzymes,with an emphasis on the structural information and inhibitors of these enzymes.展开更多
The fatty alk(a/e)ne biosynthesis pathway found in cyanobacteria gained tremendous attention in recent years as a promising alternative approach for biofuel production. Cyanobacterial aldehyde-deformylating oxygena...The fatty alk(a/e)ne biosynthesis pathway found in cyanobacteria gained tremendous attention in recent years as a promising alternative approach for biofuel production. Cyanobacterial aldehyde-deformylating oxygenase (cADO), which catalyzes the conversion of Cn fatty aldehyde to its corresponding Cn-1 alk(ale)ne, is a key enzyme in that pathway. Due to its low activity, alk(a/e)ne production by cADO is an inefficient process. Previous biochemical and structural investi. gations of cADO have provided some information on its catalytic reaction. However, the details of its cata- lytic processes remain unclear. Here we report five crystal structures of cADO from the Synechococcus elongates strain PCC7942 in both its iron-free and iron-bound forms, representing different states during its catalytic process. Structural comparisons and functional enzyme assays indicate that Giu144, one of the iron-coordinating residues, plays a vital role in the catalytic reaction of cADO. Moreover, the helix where Glu144 resides exhibits two distinct conformations that correlates with the different binding states of the di-iron center in cADO structures. Therefore, our results provide a structural explanation for the highly labile feature of cADO di-iron center, which we pro- posed to be related to its low enzymatic activity. On the basis of our structural and biochemical data, a possible catalytic process of cADO was proposed, which could aid the design of cADO with improved activity.展开更多
Nb_(2)O_(5)nanoparticles with an average particle size of 10 nm supported on a rhombic dodecahedral metal organic framework(MOF)were successfully synthesized by a facile one-pot hydrothermal reaction and subsequent ca...Nb_(2)O_(5)nanoparticles with an average particle size of 10 nm supported on a rhombic dodecahedral metal organic framework(MOF)were successfully synthesized by a facile one-pot hydrothermal reaction and subsequent calcination process.Experimental results demonstrated that the prepared catalyst drastically improved the hydrogen storage behavior of MgH_(2).7 wt%Nb_(2)O_(5)@MOF doped MgH_(2)started to desorb hydrogen at 181.9℃and 6.2 wt%hydrogen could be released within 2.6 min and 6.3 min at 275℃and 250℃,respectively.The fully dehydrogenated composite also displayed excellent hydrogenation by decreasing the onset absorption temperature to 25℃and taking up4.9 wt%and 6.5 wt%hydrogen within 6 min at 1750C and 1500C,respectively.Moreover,the corresponding activation energy was calculated to be 75.57±4.16 kJ mol^(-1)for desorption reaction and 51.38±1.09 kJ mol^(-1)for absorption reaction.After 20 cycles,0.5 wt%hydrogen capacity was lost for the MgH_(2)+7 wt%Nb_(2)O_(5)@MOF composite,much lower than 1.5 wt%of the MgH_(2)+7 wt%Nb_(2)O_(5)composite.However,the addition of Nb_(2)O_(5)@MOF had limited effect on reducing the dehydrogenation enthalpy of MgH_(2).Microstructure analysis revealed that Nb_(2)O_(5)particles were uniformly distributed on surface of the MgH_(2)matrix and synergistically improved the hydrogen storage property of MgH_(2)with MOF.展开更多
Sinceγ-glutamyltranspeptidase(GGT)especially catalyses the transfer of theγ-glutamyl moiety to a variety of amino acids and short peptides,GGT has important practical value for enzymatic synthesis ofγ-glutamyl comp...Sinceγ-glutamyltranspeptidase(GGT)especially catalyses the transfer of theγ-glutamyl moiety to a variety of amino acids and short peptides,GGT has important practical value for enzymatic synthesis ofγ-glutamyl compounds.In this paper,the GGT produced from Bacillus subtilis NX-2 was purified by a combination of ammonium sulfate fractionation and ion exchange chromatography,and the properties of purified GGT were investigated.At the conditions of pH 10.0,D-glutamine(D-Gln)/L-tryptophan(L-Trp)with a molar ratio of 5:7,a temperature 40℃ and a reaction time of 4 h,a higher conversion rate of 42%was obtained.According to the time course,the catalytic mechanism of enzymatic synthesis ofγ-D-glutamyl-L-tryptophan(γ-D-Gln-L-Trp)was discussed.It was demonstrated that the GGT can catalyze not only the reaction of transpeptidation,but also the irreversible hydrolysis of the products which results in the decrease of the yield of the products.The affinity parameter of GGT to D-Gln(Km)was 5.08 mmol·L-1 and the maximum reaction rate of transpeptidation(rmax)was determined as 0.034 mmol·min-1·L-1,while the affinity parameter of GGT toγ-D-Gln-L-Trp(K’m)was 2.267 mmol·L-1,and the maximum reaction rate of hydrolysis(r’max)was 0.012 mmol·min-1·L-1.展开更多
In this paper,the research status and catalytic mechanism of activated carbon catalysts,molecular sieve catalysts,noble metal catalysts and transition metal oxide catalysts used for NO catalytic oxidation were studied...In this paper,the research status and catalytic mechanism of activated carbon catalysts,molecular sieve catalysts,noble metal catalysts and transition metal oxide catalysts used for NO catalytic oxidation were studied to provide reference for future research.展开更多
This study explores how the chemical interaction between magnesium hydride(MgH_(2))and the additive CrO_(3) influences the hydrogen/lithium storage characteristics of MgH_(2).We have observed that a 5 wt.%CrO_(3) addi...This study explores how the chemical interaction between magnesium hydride(MgH_(2))and the additive CrO_(3) influences the hydrogen/lithium storage characteristics of MgH_(2).We have observed that a 5 wt.%CrO_(3) additive reduces the dehydrogenation activation energy of MgH_(2) by 68 kJ/mol and lowers the required dehydrogenation temperature by 80℃.CrO_(3) added MgH_(2) was also tested as an anode in an Li ion battery,and it is possible to deliver over 90%of the total theoretical capacity(2038 mAh/g).Evidence for improved reversibility in the battery reaction is found only after the incorporation of additives with MgH_(2).In depth characterization study by X-ray diffraction(XRD)technique provides convincing evidence that the CrO_(3) additive interacts with MgH_(2) and produces Cr/MgO byproducts.Gibbs free energy analyses confirm the thermodynamic feasibility of conversion from MgH_(2)/CrO_(3) to MgO/Cr,which is well supported by the identification of Cr(0)in the powder by X ray photoelectron spectroscopy(XPS)technique.Through high resolution transmission electron microscopy(HRTEM)and energy dispersive spectroscopy(EDS)we found evidence for the presence of 5 nm size Cr nanocrystals on the surface of MgO rock salt nanoparticles.There is also convincing ground to consider that MgO rock salt accommodates Cr in the lattice.These observations support the argument that creation of active metal–metal dissolved rock salt oxide interface may be vital for improving the reactivity of MgH_(2),both for the improved storage of hydrogen and lithium.展开更多
The steep reduction in costs and systematic optimization of renewable electricity has ignited an intensifying interest in harnessing electroreduction of carbon dioxide(CO_(2)RR)for the generation of chemicals and fuel...The steep reduction in costs and systematic optimization of renewable electricity has ignited an intensifying interest in harnessing electroreduction of carbon dioxide(CO_(2)RR)for the generation of chemicals and fuels.The focus of research over the past few decades has been on the optimization of the electrode and the electrolyte environment.Notably,cation species in the latter have recently been found to dramatically alter the selectivity of CO_(2)RR and even their catalytic activity by multiple orders of magnitude.As a result,the selection of cations is a critical factor in designing catalytic interfaces with high selectivity and efficiency for targeted products.Informed decision-making regarding cation selection relies on a comprehensive understanding of prevailing electrolyte effect models that have been used to elucidate observed experimental trends.In this perspective,we review the hypotheses that explain how electrolyte cations influence CO_(2)RR by mechanisms such as through tuning of the interfacial electric field,buffering of the local pH,stabilization of the key intermediates and regulation of the interfacial water.Our endeavor is to elucidate the molecular mechanisms underpinning cation effects,thus fostering the evolution of more holistic and universally applicable predictive models.In this regard,we highlight the current challenges in this area of research,while also identifying potential avenues for future investigations.展开更多
Single-atom catalysts(SACs)are gaining popularity in catalytic reactions due to their nearly 100%atomic utilization and defined active sites,which provide great convenience for studying the catalytic mechanism of cata...Single-atom catalysts(SACs)are gaining popularity in catalytic reactions due to their nearly 100%atomic utilization and defined active sites,which provide great convenience for studying the catalytic mechanism of catalysts.However,SACs still present challenges such as complex formation processes,low loading and easy agglomeration of catalysts.Herein,we systematically discuss the synthesis methods for SACs,including coprecipitation,impregnation,atomic layer deposition,pyrolysis and Anti-Ostwald ripening etc.Various techniques for characterizing single-atom catalysts(SACs)are described in detail.The utilization of individual atoms in various photocatalytic reactions and their mechanisms of action in different reactions are explained.The purpose of this review is to introduce single-atom synthesis methods,characterization techniques,specific catalytic action and their applications in the direction of photocatalysis,and to provide a reference for the industrialization of photocatalytic single-atoms,which is currently impossible,in the hope of promoting further development of photocatalytic single-atoms.展开更多
Since the ferromagnetic(Fe_(3)O_(4))nanoparticles were firstly reported to exert enzyme-like activity in 2007,extensive research progress in nanozymes has been made with deep investigation of diverse nanozymes and rap...Since the ferromagnetic(Fe_(3)O_(4))nanoparticles were firstly reported to exert enzyme-like activity in 2007,extensive research progress in nanozymes has been made with deep investigation of diverse nanozymes and rapid development of related nanotechnologies.As promising alterna-tives for natural enzymes,nanozymes have broadened the way toward clinical medicine,food safety,environmental monitoring,and chemical production.The past decade has witnessed the rapid development of metal-and metal oxide-based nanozymes owing to their remarkable physicochemical proper-ties in parallel with low cost,high stability,and easy storage.It is widely known that the deep study of catalytic activities and mechanism sheds sig-nificant influence on the applications of nanozymes.This review digs into the characteristics and intrinsic properties of metal-and metal oxide-based nanozymes,especially emphasizing their catalytic mechanism and recent applications in biological analysis,relieving inflammation,antibacterial,and cancer therapy.We also conclude the present challenges and provide insights into the future research of nanozymes constituted of metal and metal oxide nanomaterials.展开更多
As a primary type of clean energy,methane is also the second most important greenhouse gas after CO_(2)due to the high global warming potential.Large quantities of lean methane(0.1–1.0 vol%)are emitted into the atmos...As a primary type of clean energy,methane is also the second most important greenhouse gas after CO_(2)due to the high global warming potential.Large quantities of lean methane(0.1–1.0 vol%)are emitted into the atmosphere without any treatment during coal mine,oil,and natural gas production,thus leading to energy loss and greenhouse effect.In general,it is challenging to utilize lean methane due to its low concentration and flow instability,while catalytic combustion is a vital pathway to realize an efficient utilization of lean methane owing to the reduced emissions of polluting gases(e.g.,NOxand CO)during the reaction.In particular,to efficiently convert lean methane,it necessitates both the designs of highly active and stable heterogeneous catalysts that accelerate lean methane combustion at low temperatures and smart reactors that enable autothermal operation by optimizing heat management.In this review,we discuss the in-depth development,challenges,and prospects of catalytic lean methane combustion technology in various configurations,with particular emphasis on heat management from the point of view of material design combined with reactor configuration.The target is to describe a framework that can correlate the guiding principles among catalyst design,device innovation and system optimization,inspiring the development of groundbreaking combustion technology for the efficient utilization of lean methane.展开更多
Uniform-uispersed Ni nanoparticics(NPs)anchored on reduced graphene oxide(Ni@rGO)catalyzed MgH2(MH-Ni@rGO)has been fabricated by mechanical milling.The effects of milling time and Ni loading amount on the hydrogen sto...Uniform-uispersed Ni nanoparticics(NPs)anchored on reduced graphene oxide(Ni@rGO)catalyzed MgH2(MH-Ni@rGO)has been fabricated by mechanical milling.The effects of milling time and Ni loading amount on the hydrogen storage properties of MgH2 have been investigated.The initial hydrogen desorption temperature of MgH2 catalyzed by 10 wt.%Ni4@rGO6 for milling 5 h is significantly decreased from 251℃ to 190℃.The composite can absorb 5.0 wt.%hydrogen in 20 min at 100℃,while it can desorb 6.1 wt.%within 15 min at 300℃.Through the investigation of the phase transformation and dehydrogenation kinetics during hydrogen ab/desorption cycles,we found that the in-situ formed Mg2Ni/Mg2NiH4 exhibited better catalytic effect than Ni.When Ni loading amount is 45 wt.%,the rGO in Ni@rGO catalysts can prevent the reaction of Ni and Mg due to the strong interaction between rGO and Ni NPs.展开更多
基金the National Natural Science Foundation of China(21962008)Yunnan Province Excellent Youth Fund Project(202001AW070005)+1 种基金Candidate Talents Training Fund of Yunnan Province(2017PY269SQ,2018HB007)Yunnan Ten Thousand Talents Plan Young&Elite Talents Project(YNWR-QNBJ-2018-346).
文摘Electrochemical water splitting has long been considered an effective energy conversion technology for trans-ferring intermittent renewable electricity into hydrogen fuel,and the exploration of cost-effective and high-performance electrocatalysts is crucial in making electrolyzed water technology commercially viable.Cobalt phosphide(Co-P)has emerged as a catalyst of high potential owing to its high catalytic activity and durability in water splitting.This paper systematically reviews the latest advances in the development of Co-P-based materials for use in water splitting.The essential effects of P in enhancing the catalytic performance of the hydrogen evolution reaction and oxygen evolution reaction are first outlined.Then,versatile synthesis techniques for Co-P electrocatalysts are summarized,followed by advanced strategies to enhance the electrocatalytic performance of Co-P materials,including heteroatom doping,composite construction,integration with well-conductive sub-strates,and structure control from the viewpoint of experiment.Along with these optimization strategies,the understanding of the inherent mechanism of enhanced catalytic performance is also discussed.Finally,some existing challenges in the development of highly active and stable Co-P-based materials are clarified,and pro-spective directions for prompting the wide commercialization of water electrolysis technology are proposed.
基金supported by the financial supports from Science and Technology Commission of Shanghai Municipality(No.19ZR1418400)the National Natural Science Foundation of China(No.51971126)+1 种基金Guangdong Innovation Research Team for Higher Education(2017KCXTD030)the Science and Technology Committee of Shanghai(19010500400).
文摘In this work,we synthesized MoS_(2)catalyst via one-step hydrothermal method,and systematically investigated the catalytic effect of MoS_(2)on the hydrogen storage properties of MgH_(2).The MgH_(2)-5MoS_(2)composite milled for 5 h starts to release hydrogen at 259℃.Furthermore,it can desorb 4.0 wt.%hydrogen within 20 min at 280℃,and absorb 4.5 wt.%hydrogen within 5 min at 200℃.Mo and MoS_(2)coexistedin the ball milled sample,whereas only Mo was kept in the sample after dehydrogenation and rehydrogenation,which greatly weakens theMg-H bonds and facilitates the dissociation of MgH_(2)on the surface of Mo(110).The comparative study show that the formed MgS has nocatalytic effect for MgH_(2).We believed that the evolution and the catalytic mechanism of MoS_(2)will provide the theoretical guidance for theapplication of metal sulfide in hydrogen storage materials.
基金financially supported by Key Projects of National Natural Science Foundation of China(No.21736007)National Natural Science Foundation of China(Nos.22078221,21776193,21476155)Top Young Innovative Talents of Shanxi。
文摘In the conversion process of syngas-to-C_(2)species,the OH species are inevitably produced accompanying the production of key intermediates CH_(x)(x=1-3),traditionally,the function of surface OH species is generally accepted as the hydrogenating reactive species.This work for the first time proposed and confirmed the assisted catalytic mechanism of surface OH species that performed as the promoter for syngas-to-C_(2)species on Cu-based catalysts.DFT and microkinetic modeling results reveal that the produced OH species accompanying the intermediates CH_(x)production on the MCu(M=Co,Fe,Rh)catalysts can stably exist to form OH/MCu catalysts,on which the presence of surface OH species as the promoter not only presented better activity and selectivity toward CH_(x)(x=1-3)compared to MCu catalysts,but also significantly suppressed CH_(3)OH production,providing enough CH_(x)sources to favor the production of C_(2)hydrocarbons and oxygenates.Correspondingly,the electronic properties analysis revealed the essential relationship between the electronic feature of OH/MCu catalysts and catalytic performance,attributing to the unique electronic micro-environment of the catalysts under the interaction of surface OH species.This new mechanism is called as OH-assisted catalytic mechanism,which may be applied in the reaction systems related to the generation of OH species.
基金financial support from the National Natural Science Foundation of China (NSFC,2052010)
文摘The alkylation mechanism catalyzed by an ionic liquid (as a Lewis acid) may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene (C 6 D 6) with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] +H + and [AlHCl 3 ] + +[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] + is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] + which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.
基金supported by the National Natural Science Foundation(Nos.22022801,21878016)National Key Research and Development Program of China(No.2016YFB0301601)the Fundamental Research Funds for the Central Universities(Nos.BHYC1701B,JD2004)。
文摘The interaction between the metal and the support of supported metal catalysts, which are widely used in industry, is the primary focus of the study of such catalysts. With the developing understanding of the metal–support interaction, the intrinsic factor that influences the catalytic performance has been determined to be the structure of interfacial sites. Layered double hydroxides(LDHs, a class of two-dimensional layered anion clay) possess several unique characteristics, such as the following:(1) tunable elemental component, homogeneous distribution of metal cations.(2) anchoring eff ect.(3) multiple layered structure for exfoliation or intercalation and special memory eff ect;and(4) internal/external confinement eff ects during topological transformation. Taking LDHs and their derivatives as precursors or supports shows superior advantages in designing interfacial active catalysts with tunable properties. Therefore, this review is mainly focused on constructing interfacial active catalysts by LDHs and revealing the interfacial eff ects(including electronic, geometric, and bifunctional eff ects) on the catalytic performance that will provide new perspectives and approaches for the development of heterogeneous catalysis.
基金Project supported by the National High Technology Research & Development of China (Grant No. 2009AA05Z105)the National Natural Science Foundation of China (Grant No. 50671069)+1 种基金the Science Research Program of the Education Bureau of Liaoning Province of China (Grant Nos. 2008S345,2008511 and 2007T165)the Financial Support from Shenyang Normal University
文摘Experiments on a ball milled mixture with a 1:1 molar ratio of LiNH2 and LiH with a small amount (1 mol %) of Ti^nano, TICl3 and TiO2^nano have revealed a superior catalytic effect on Li N H hydrogen storage materials. In the x-ray diffraction profiles, no trace of Ti^nano, TICl3 and TiO2^nano was found in these doped composites, by which we deduced that Ti atoms enter LiNH2 by partial element substitution. A first-principles plane-wave pseudopotential method based on density functional theory has been used to investigate the catalytic effects of Ti catalysts on the dehydrogenating properties of LiNH2 system. The results show that Ti substitution can reduce the dehydrogenation reaction activation energy of LiNH2 and improve the dehydrogenating properties of LiNH2. Based on the analysis of the density of states and overlap populations for LiNH2 before and after Ti substitution, it was found that the stability of the system of LiNH2 is reduced, which originates from the increase of the valence electrons at the Fermi level (EF) and the decrease of the highest occupied molecular orbital (HOMO) lowest unoccupied molecular orbital (LUMO) gap (△EH-L) near EF. The catalytic effect of Ti on the dehydrogenating kinetics of LiNH2 may be attributed to the reduction of average populations between N-H per unit bond length (nm-1), which leads to the reduction of the chemical bond strength of NH.
基金supported by grants from “Double First-Class” University project (No.CPU2018GY25)Jiangsu Innovation and Enterpreneurship。
文摘Nanomaterials with enzyme-mimic(nanozyme) activity have garnered considerable attention as a potential alternative to natural enzymes, thanks to their low preparation cost, high activity, ease of preservation, and unique physicochemical properties. Vanadium(V) is a transition metal that integrates the benefits of valence-richness, low cost, and non-toxicity, making it a desirable candidate for developing a range of emerging nanozymes. In this review, we provide the first systematic summary of recent research progress on V-based nanozymes. First, we summarize the preparation of V-based nanozymes using both top-down and bottom-up synthesis methods. Next, we review the mechanism of V-based nanozymes that mimic the activity of various enzymes. We then discuss methods for regulating V-based nanozyme activity, including morphology, size, valence engineering, defect engineering, external triggering, and surface engineering. Afterward, we outline various biomedical applications, including therapeutic, anti-inflammatory, antibacterial, and biosensing. Finally, we prospect the challenges and countermeasures for V-based nanozymes based on their development. By summarizing recent research progress on V-based nanozymes, we hope to provide useful insights for researchers to further explore their potential applications and overcome their existing challenges.
基金supported by Natural Science Foundation of Henan Province(NO.202300410433)ZiQoo Chemical Co.Ltd,Japan.We also appreciate Mr Lijie Hou of the Shiyanjia Lab(www.shiyanjia.com)for providing the supporting materials.
文摘Among various electrocatalysts,high entropy materials(HEMs)have attracted great attention due to the distinctive designing concept and unique properties with captivating electrocatalytic activity and stability.To date,HEMs have been a new family of advanced electrocatalysts in the research field of water electrolysis.In this work,the structural features and synthesis strategies of high entropy catalysts are reviewed,especially,their performances for catalyzing hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in water electrolysis are presented,in which the crucial roles of structure,composition,multisites synergy,and“four core effects”for enhancing catalytic activity,stability,and resistance of electrochemical corrosion are introduced.Besides,the design tactics,main challenges,and future prospects of HEM-based electrocatalysts for HER and OER are discussed.It is expected to provide valuable information for the development of low-cost efficient HEM-based electrocatalysts in the field of water electrolysis.
基金S.G.acknowledges the financial support from the National Natural Science Foundation of China(NSFC 52272144,51972076)the Heilongjiang Provincial Natural Science Foundation of China(JQ2022E001)+4 种基金the Natural Science Foundation of Shandong Province(ZR2020ZD42)the Fundamental Research Funds for the Central Universities.H.D.acknowledges the financial support from the National Natural Science Foundation of China(NSFC 22205048)China Postdoctoral Science Foundation(2022M710931 and 2023T160154)Heilongjiang Postdoctoral Science Foundation(LBH-Z22010)G.Y.acknowledges the financial support from the National Science Foundation of Heilongjiang Education Department(324022075).
文摘Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007,nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity,low cost,mild reaction conditions,good stability,and suitable for large-scale production.Recently,with the cross fusion of nanomedicine and nanocatalysis,nanozyme-based theranostic strategies attract great attention,since the enzymatic reactions can be triggered in the tumor microenvironment to achieve good curative effect with substrate specificity and low side effects.Thus,various nanozymes have been developed and used for tumor therapy.In this review,more than 270 research articles are discussed systematically to present progress in the past five years.First,the discovery and development of nanozymes are summarized.Second,classification and catalytic mechanism of nanozymes are discussed.Third,activity prediction and rational design of nanozymes are focused by highlighting the methods of density functional theory,machine learning,biomimetic and chemical design.Then,synergistic theranostic strategy of nanozymes are introduced.Finally,current challenges and future prospects of nanozymes used for tumor theranostic are outlined,including selectivity,biosafety,repeatability and stability,in-depth catalytic mechanism,predicting and evaluating activities.
文摘Epigenetic modifications alter chromatin structures and consequently affect transcription and cellular functions.Major epigenetic markers include DNA methylation and histone acetylation and methylation.The modifications are reversible and are achieved in aid of relative enzymes.Much effort has been directed at the understanding of the chemical mechanisms of individual catalytic reactions,which can serve as a foundation for inhibitor development.Among the many methods deployed,structural studies have proven the most effective for understanding enzyme-mediated modifications and have provided support for the development of lead-candidate drug inhibitors.This review briefly summarizes the existing knowledge on the catalytic mechanisms of the major epigenetic modification enzymes,with an emphasis on the structural information and inhibitors of these enzymes.
基金We would like to thank Yi Han and Shengquan Liu at the Institute of Biophysics, CAS and the staffs at Shanghai Synchrotron Radiation Facility and Photo Factory, Japan, respectively, for help during X-ray data collection. We also thank Wei Shao at Beijing Center for Physical and Chemical Analysis for help with the GC analysis, Zhen Xue at Institute of Botany, CAS for providing help for the GC-QqQ- MS/MS analysis, and Hongzhi Zhang at Institute of Geographic Sciences and Natural Resources Research, CAS for technical support with the metal content analysis by ICP-OES. This work was supported by the National Basic Research Program (973 Program) (Nos. 2011CBA00902 and 2011CBA00907), Strategic Priority Research Program of the Chinese Academy of Sciences (XDB08020302), National Natural Science Foundation of China(Grant Nos. 31021062 and 31170765), and CAS Cross and Coop- eration Team for Scientific Innovation (Y31102110A).
文摘The fatty alk(a/e)ne biosynthesis pathway found in cyanobacteria gained tremendous attention in recent years as a promising alternative approach for biofuel production. Cyanobacterial aldehyde-deformylating oxygenase (cADO), which catalyzes the conversion of Cn fatty aldehyde to its corresponding Cn-1 alk(ale)ne, is a key enzyme in that pathway. Due to its low activity, alk(a/e)ne production by cADO is an inefficient process. Previous biochemical and structural investi. gations of cADO have provided some information on its catalytic reaction. However, the details of its cata- lytic processes remain unclear. Here we report five crystal structures of cADO from the Synechococcus elongates strain PCC7942 in both its iron-free and iron-bound forms, representing different states during its catalytic process. Structural comparisons and functional enzyme assays indicate that Giu144, one of the iron-coordinating residues, plays a vital role in the catalytic reaction of cADO. Moreover, the helix where Glu144 resides exhibits two distinct conformations that correlates with the different binding states of the di-iron center in cADO structures. Therefore, our results provide a structural explanation for the highly labile feature of cADO di-iron center, which we pro- posed to be related to its low enzymatic activity. On the basis of our structural and biochemical data, a possible catalytic process of cADO was proposed, which could aid the design of cADO with improved activity.
基金fiscal funding from the National Natural Science Foundation of China(No.51801078)the Natural Science Foundation of Jiangsu Province(No.BK20180986)。
文摘Nb_(2)O_(5)nanoparticles with an average particle size of 10 nm supported on a rhombic dodecahedral metal organic framework(MOF)were successfully synthesized by a facile one-pot hydrothermal reaction and subsequent calcination process.Experimental results demonstrated that the prepared catalyst drastically improved the hydrogen storage behavior of MgH_(2).7 wt%Nb_(2)O_(5)@MOF doped MgH_(2)started to desorb hydrogen at 181.9℃and 6.2 wt%hydrogen could be released within 2.6 min and 6.3 min at 275℃and 250℃,respectively.The fully dehydrogenated composite also displayed excellent hydrogenation by decreasing the onset absorption temperature to 25℃and taking up4.9 wt%and 6.5 wt%hydrogen within 6 min at 1750C and 1500C,respectively.Moreover,the corresponding activation energy was calculated to be 75.57±4.16 kJ mol^(-1)for desorption reaction and 51.38±1.09 kJ mol^(-1)for absorption reaction.After 20 cycles,0.5 wt%hydrogen capacity was lost for the MgH_(2)+7 wt%Nb_(2)O_(5)@MOF composite,much lower than 1.5 wt%of the MgH_(2)+7 wt%Nb_(2)O_(5)composite.However,the addition of Nb_(2)O_(5)@MOF had limited effect on reducing the dehydrogenation enthalpy of MgH_(2).Microstructure analysis revealed that Nb_(2)O_(5)particles were uniformly distributed on surface of the MgH_(2)matrix and synergistically improved the hydrogen storage property of MgH_(2)with MOF.
文摘Sinceγ-glutamyltranspeptidase(GGT)especially catalyses the transfer of theγ-glutamyl moiety to a variety of amino acids and short peptides,GGT has important practical value for enzymatic synthesis ofγ-glutamyl compounds.In this paper,the GGT produced from Bacillus subtilis NX-2 was purified by a combination of ammonium sulfate fractionation and ion exchange chromatography,and the properties of purified GGT were investigated.At the conditions of pH 10.0,D-glutamine(D-Gln)/L-tryptophan(L-Trp)with a molar ratio of 5:7,a temperature 40℃ and a reaction time of 4 h,a higher conversion rate of 42%was obtained.According to the time course,the catalytic mechanism of enzymatic synthesis ofγ-D-glutamyl-L-tryptophan(γ-D-Gln-L-Trp)was discussed.It was demonstrated that the GGT can catalyze not only the reaction of transpeptidation,but also the irreversible hydrolysis of the products which results in the decrease of the yield of the products.The affinity parameter of GGT to D-Gln(Km)was 5.08 mmol·L-1 and the maximum reaction rate of transpeptidation(rmax)was determined as 0.034 mmol·min-1·L-1,while the affinity parameter of GGT toγ-D-Gln-L-Trp(K’m)was 2.267 mmol·L-1,and the maximum reaction rate of hydrolysis(r’max)was 0.012 mmol·min-1·L-1.
基金Supported by General Project of Natural Science Foundation of Liaoning Province in 2019(2019-MS-202)"Double First-Class"Construction Project of Liaoning Province in 2020(Scientific Research)(FWDFGD2020041)。
文摘In this paper,the research status and catalytic mechanism of activated carbon catalysts,molecular sieve catalysts,noble metal catalysts and transition metal oxide catalysts used for NO catalytic oxidation were studied to provide reference for future research.
基金supported by the projects UIDB/00481/2020 and UIDP/00481/2020-Fundação para a Ciência e a Tecnologia,DOI 10.54499/UIDB/00481/2020(https://doi.org/10.54499/UIDB/00481/2020)and DOI 10.54499/UIDP/00481/2020(https://doi.org/10.54499/UIDP/00481/2020)supported by CENTRO-01-0145-FEDER-022083-Centro Portugal Regional Operational Programme(Centro 2020),under the PORTUGAL 2020 Partnership Agreement,through the European Regional Development Fund(ERDF).This article is a result of the Innovation Pact“NGS-New Generation Storage”(C644936001-00000045)+3 种基金by“NGS”Consortium,co-financed by NextGeneration EU,through the Incentive System“Agendas para a Inovação Empresarial”(“Agendas for Business Innovation”)within the Recovery and Resilience Plan(PRR).D.P acknowledges FCT,Portugal for the financial support with reference CEECIND/04158/2017(https://doi.org/10.54499/CEECIND/04158/2017/CP1459/CT0029)funding from the SMART-ER project,funded by the European Union’s Horizon 2020 research and innovation programme under Grant Agreement#101016888.support granted by the Recovery and Resilience Plan(PRR)and by the Next Generation EU European Funds to Universidade de Aveiro,through the Agenda for Business Innovation“NGS-Next Generation Storage”(Project no 02/C05-i01.01/2022 with the application C644936001-00000045).
文摘This study explores how the chemical interaction between magnesium hydride(MgH_(2))and the additive CrO_(3) influences the hydrogen/lithium storage characteristics of MgH_(2).We have observed that a 5 wt.%CrO_(3) additive reduces the dehydrogenation activation energy of MgH_(2) by 68 kJ/mol and lowers the required dehydrogenation temperature by 80℃.CrO_(3) added MgH_(2) was also tested as an anode in an Li ion battery,and it is possible to deliver over 90%of the total theoretical capacity(2038 mAh/g).Evidence for improved reversibility in the battery reaction is found only after the incorporation of additives with MgH_(2).In depth characterization study by X-ray diffraction(XRD)technique provides convincing evidence that the CrO_(3) additive interacts with MgH_(2) and produces Cr/MgO byproducts.Gibbs free energy analyses confirm the thermodynamic feasibility of conversion from MgH_(2)/CrO_(3) to MgO/Cr,which is well supported by the identification of Cr(0)in the powder by X ray photoelectron spectroscopy(XPS)technique.Through high resolution transmission electron microscopy(HRTEM)and energy dispersive spectroscopy(EDS)we found evidence for the presence of 5 nm size Cr nanocrystals on the surface of MgO rock salt nanoparticles.There is also convincing ground to consider that MgO rock salt accommodates Cr in the lattice.These observations support the argument that creation of active metal–metal dissolved rock salt oxide interface may be vital for improving the reactivity of MgH_(2),both for the improved storage of hydrogen and lithium.
基金Financial support from National Natural Science Foundation of China(Nos.22109099 and 22072101)“Chen Guang”Project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation(No.21CGA66)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20211306)Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘The steep reduction in costs and systematic optimization of renewable electricity has ignited an intensifying interest in harnessing electroreduction of carbon dioxide(CO_(2)RR)for the generation of chemicals and fuels.The focus of research over the past few decades has been on the optimization of the electrode and the electrolyte environment.Notably,cation species in the latter have recently been found to dramatically alter the selectivity of CO_(2)RR and even their catalytic activity by multiple orders of magnitude.As a result,the selection of cations is a critical factor in designing catalytic interfaces with high selectivity and efficiency for targeted products.Informed decision-making regarding cation selection relies on a comprehensive understanding of prevailing electrolyte effect models that have been used to elucidate observed experimental trends.In this perspective,we review the hypotheses that explain how electrolyte cations influence CO_(2)RR by mechanisms such as through tuning of the interfacial electric field,buffering of the local pH,stabilization of the key intermediates and regulation of the interfacial water.Our endeavor is to elucidate the molecular mechanisms underpinning cation effects,thus fostering the evolution of more holistic and universally applicable predictive models.In this regard,we highlight the current challenges in this area of research,while also identifying potential avenues for future investigations.
基金financially supported by the National Natural Science Foundation of China (22172044 and 22208048)Heilongjiang Provincial Natural Science Foundation of China (YQ2022B005 and YQ2022B001)+4 种基金the Young Elite Scientists Sponsorship Program by CAST (No.YESS20210262)the China Postdoctoral Science Foundation-Funded Project (No.2021M690571)the Heilongjiang Postdoctoral Fund (No.LBH-Z21096)the Provincial Natural Science Foundation Joint Guidance Project (No.LH2020F001)the Fundamental Research Funds for the Central Universities (No.2572023CT10)。
文摘Single-atom catalysts(SACs)are gaining popularity in catalytic reactions due to their nearly 100%atomic utilization and defined active sites,which provide great convenience for studying the catalytic mechanism of catalysts.However,SACs still present challenges such as complex formation processes,low loading and easy agglomeration of catalysts.Herein,we systematically discuss the synthesis methods for SACs,including coprecipitation,impregnation,atomic layer deposition,pyrolysis and Anti-Ostwald ripening etc.Various techniques for characterizing single-atom catalysts(SACs)are described in detail.The utilization of individual atoms in various photocatalytic reactions and their mechanisms of action in different reactions are explained.The purpose of this review is to introduce single-atom synthesis methods,characterization techniques,specific catalytic action and their applications in the direction of photocatalysis,and to provide a reference for the industrialization of photocatalytic single-atoms,which is currently impossible,in the hope of promoting further development of photocatalytic single-atoms.
基金the supports of the National Foundational Basic Research Project of China(2017YFA0205301)National Nature Scientific Foundation Innovation Team of China(81921002)+6 种基金National Nature Scientific foundation of China(8202010801,81903169,81803094,81602184,81822024 and 81571729)Shanghai Municipal Commission of Economy and Information Technology Fund(No.XC-ZXSJ-02-2016-05)the medical engineering cross project of Shanghai Jiao Tong University(YG2017Z D05)the Project of Thousand Youth Talents from Chinathe National Key Research and Development Program of China(2017YFC1200904)the financial support of China Postdoctoral Science Foundation(2020TQ0191)Shanghai Engineering Research Center for Intelligent Diagnosis and Treatment Instrument(No.15DZ2252000)。
文摘Since the ferromagnetic(Fe_(3)O_(4))nanoparticles were firstly reported to exert enzyme-like activity in 2007,extensive research progress in nanozymes has been made with deep investigation of diverse nanozymes and rapid development of related nanotechnologies.As promising alterna-tives for natural enzymes,nanozymes have broadened the way toward clinical medicine,food safety,environmental monitoring,and chemical production.The past decade has witnessed the rapid development of metal-and metal oxide-based nanozymes owing to their remarkable physicochemical proper-ties in parallel with low cost,high stability,and easy storage.It is widely known that the deep study of catalytic activities and mechanism sheds sig-nificant influence on the applications of nanozymes.This review digs into the characteristics and intrinsic properties of metal-and metal oxide-based nanozymes,especially emphasizing their catalytic mechanism and recent applications in biological analysis,relieving inflammation,antibacterial,and cancer therapy.We also conclude the present challenges and provide insights into the future research of nanozymes constituted of metal and metal oxide nanomaterials.
基金financially supported by the National Natural Science Foundation of China(21922606,21876139)the National Natural Science Foundation of Shaanxi Province(2020JQ-919)+2 种基金the Shaanxi Natural Science Fundamental Shaanxi Coal Chemical Joint Fund(2019JLM-14)the Initial Scientific Research Fund for Special Zone’s Talents(XJ18T06)K.C.Wong Education Foundation。
文摘As a primary type of clean energy,methane is also the second most important greenhouse gas after CO_(2)due to the high global warming potential.Large quantities of lean methane(0.1–1.0 vol%)are emitted into the atmosphere without any treatment during coal mine,oil,and natural gas production,thus leading to energy loss and greenhouse effect.In general,it is challenging to utilize lean methane due to its low concentration and flow instability,while catalytic combustion is a vital pathway to realize an efficient utilization of lean methane owing to the reduced emissions of polluting gases(e.g.,NOxand CO)during the reaction.In particular,to efficiently convert lean methane,it necessitates both the designs of highly active and stable heterogeneous catalysts that accelerate lean methane combustion at low temperatures and smart reactors that enable autothermal operation by optimizing heat management.In this review,we discuss the in-depth development,challenges,and prospects of catalytic lean methane combustion technology in various configurations,with particular emphasis on heat management from the point of view of material design combined with reactor configuration.The target is to describe a framework that can correlate the guiding principles among catalyst design,device innovation and system optimization,inspiring the development of groundbreaking combustion technology for the efficient utilization of lean methane.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51671118)the research grant(No.16520721800 and No.19ZR1418400)from Science and Technology Commission of Shanghai Municipality.The authors gratefully acknowledge support for materials analysis and research from Instrumental Analysis and Research Center of Shanghai University.
文摘Uniform-uispersed Ni nanoparticics(NPs)anchored on reduced graphene oxide(Ni@rGO)catalyzed MgH2(MH-Ni@rGO)has been fabricated by mechanical milling.The effects of milling time and Ni loading amount on the hydrogen storage properties of MgH2 have been investigated.The initial hydrogen desorption temperature of MgH2 catalyzed by 10 wt.%Ni4@rGO6 for milling 5 h is significantly decreased from 251℃ to 190℃.The composite can absorb 5.0 wt.%hydrogen in 20 min at 100℃,while it can desorb 6.1 wt.%within 15 min at 300℃.Through the investigation of the phase transformation and dehydrogenation kinetics during hydrogen ab/desorption cycles,we found that the in-situ formed Mg2Ni/Mg2NiH4 exhibited better catalytic effect than Ni.When Ni loading amount is 45 wt.%,the rGO in Ni@rGO catalysts can prevent the reaction of Ni and Mg due to the strong interaction between rGO and Ni NPs.