Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical capacity.Toward the broader implementation,the primary obstacle lies in the intricate multi-elec...Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical capacity.Toward the broader implementation,the primary obstacle lies in the intricate multi-electron,multi-step redox reaction associated with sluggish conversion kinetics,subsequently giving rise to a cascade of parasitic issues.In order to smooth reaction kinetics,catalysts are widely introduced to accelerate reaction rate via modulating the energy barrier.Over past decades,a large amount of research has been devoted to the catalyst design and catalytic mechanism exploration,and thus the great progress in electrochemical performance has been realized.Therefore,it is necessary to make a comprehensive review toward key progress in catalyst design and future development pathway.In this review,the basic mechanism of lithium metal batteries is provided along with corresponding advantages and existing challenges detailly described.The main catalysts employed to accelerate cathode reaction with emphasis on their catalytic mechanism are summarized as well.Finally,the rational design and innovative direction toward efficient catalysts are suggested for future application in metal-sulfur/gas battery and beyond.This review is expected to drive and benefit future research on rational catalyst design with multi-parameter synergistic impacts on the activity and stability of next-generation metal battery,thus opening new avenue for sustainable solution to climate change,energy and environmental issues,and the potential industrial economy.展开更多
The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and ...The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.展开更多
Lithium borohydride(LiBH_(4))is regarded as a potential hydrogen storage material due to its high gravi-metric and volumetric capacity,but its practical application suffers from high operating temperature and poor rev...Lithium borohydride(LiBH_(4))is regarded as a potential hydrogen storage material due to its high gravi-metric and volumetric capacity,but its practical application suffers from high operating temperature and poor reversibility.Herein,porous hollow carbon microspheres composed of carbon-coated Ni nanoparti-cles with high content(denoted as Ni/C)are rationally designed as functional support,which not only induces effective nanoconfinement of LiBH4 but also promotes efficiently homogeneous destabilization reaction between LiBH4 and Ni nanoparticles.The introduction of Ni nanoparticles leads to the decrease of the Gibbs free energy change for H_(2)desorption of LiBH4 based on the formation of Ni_(2)B down to−0.95 eV while this value reaches 1.19 eV for bulk LiBH4,validating the effective role of Ni in thermo-dynamically destabilizing H_(2)desorption.Impressively,the average B-H bond length of LiBH4 on Ni_(2)B reaches 1.291A and thus the corresponding dissociation energy of removing one H atom from LiBH4 is lowered to 1.00 eV,much lower than bulk LiBH4(4.22 eV)and even LiBH4 on Ni(1.27 eV),which verifies superior role of Ni_(2)B than Ni in catalytically enhancing H_(2)desorption.Therefore,a capacity of 8.86 wt.%is obtained for LiBH4 confined into Ni/C at 320℃ after 10 cycles.展开更多
The monodispersed Co nanoparticles were successfully prepared by means of hydrogen plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were char...The monodispersed Co nanoparticles were successfully prepared by means of hydrogen plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by transmission electron microscopy （TEM）, BET equation, X-ray diffraction （XRD）, and the corresponding selected area electron diffraction （SAED）. The catalytic effect of Co nanoparticles on the decomposition of ammonium perchlorate （AP） was investigated by differential thermal analyzer （DTA）. Compared with the thermal decomposition of pure AP, the addition of Co nanoparticles （2%-10%, by mass） decreases the decomposition temperature of AP by 145.01-155.72℃. Compared with Co3O4 nano-particles and microsized Co particles, the catalytic effect of Co nanoparticles for AP is stronger. Such effect is attributed to the large specific surface area and its interaction of Co with decomposition intermediate gases. The present work provides useful information for the application of Co nanoparficles in the AP-based propellant.展开更多
By transition metals （Fe, Ni, Mn, Co） and their alloys as catalysts during the diamond synthesis, some transition phases will be formed, such as FeaC type carbides and y solid solutions. Based on the empirical elect...By transition metals （Fe, Ni, Mn, Co） and their alloys as catalysts during the diamond synthesis, some transition phases will be formed, such as FeaC type carbides and y solid solutions. Based on the empirical electron theory of the solid and molecules, the valence electron structures of different kinds of carbides and y solid solutions and the relative electron density differences of various diamond/carbide and y solid solution/carbide interfaces were calculated and analyzed in this paper. The electron structure conditions of the ideal catalyst were presented by analyzing the different catalytic effects of the catalysts, which provide a new theoretical path to the optimal design of the catalyst composition展开更多
Catalysis and regeneration efficiency of granular activated carbon （GAC） and activated carbon fiber （ACF） were investigated in a non-equilibrium plasma water treatment reactor with a combination of pulsed streamer...Catalysis and regeneration efficiency of granular activated carbon （GAC） and activated carbon fiber （ACF） were investigated in a non-equilibrium plasma water treatment reactor with a combination of pulsed streamer discharge and GAC or ACF. The experimental results show that the degradation efficiency of methyl orange （MO） by the combined treatment can increase 22% （for GAC） and 24% （for ACF） respectively compared to pulsed discharge treatment alone, indicating that the combined treatment has a synergetic effect. The MO degradation efficiency by the combined treatment with pulsed discharge and saturated GAC or ACF can increase 12% and 17% respectively compared to pulsed discharge treatment alone. Both GAC and ACF show catalysis and the catalysis of ACF is prominent. Meanwhile, the regeneration of GAC and ACF are realized in this process. When H202 is introduced into the system, the utilization efficiency of ozone and ultraviolet light is improved and the regeneration efficiency of GAC and ACF is also increased.展开更多
The preparation method of H_4MoO_(26)-polyaniline film modified electrode and its voltammetric behaviour are described. The modified electrode has high electrocatalytic activity on chlorate ions.
The electrodeposition of zinc nickle alloy was obtained on a copper cathode of 1×1cm 2. The deposited alloys are quantitatively analyzed by atomic absorption spectrometry. The morphology of the deposits was obs...The electrodeposition of zinc nickle alloy was obtained on a copper cathode of 1×1cm 2. The deposited alloys are quantitatively analyzed by atomic absorption spectrometry. The morphology of the deposits was observed by means of scanning electron microscopy(SEM).We observed that the electrodeposition of zinc nickle alloy is an anomalous codeposition. The catalytic effects of SCN - on the electrochemical behavior of Ni deposition and hydrogen discharge are obvious. SEM analysis shows that the surface morphology of the coating appears to be more compact and homogeneous with the increase of SCN - concentration.展开更多
Kinetics of carbothermic reduction of manganese oxide and the catalyticeffect of La_2O_3 on the reduction have been studied by the measurement of mass loss in N_2atmosphere at different temperatures and followed by SE...Kinetics of carbothermic reduction of manganese oxide and the catalyticeffect of La_2O_3 on the reduction have been studied by the measurement of mass loss in N_2atmosphere at different temperatures and followed by SEM analysis. It is concluded that the kineticsof carbothermic reduction of manganese oxide is divided into three stages: gas diffusioncontrolling stage, carbon gasification con-trolling stage and solid state diffusion controllingstage. La_2O_3 has catalytic effect on the reduction. The catalytic effect of La_2O_3 increases withthe added amount of La_2O_3. SEM analysis shows that the catalytic mechanism is that La_2O_3promotes the transfer of oxygen ions so that carbon gasifying is catalyzed and thus carbothermicreduction of MnO_2 is catalyzed.展开更多
Strong metal–support interaction(SMSI),namely the strong electronic and structural interaction between metal nanoparticles and supports,one of the most typical synergetic catalytic effects in composite catalysts,has ...Strong metal–support interaction(SMSI),namely the strong electronic and structural interaction between metal nanoparticles and supports,one of the most typical synergetic catalytic effects in composite catalysts,has been found critically important in the design of catalyst for thermocatalysis in the past.Recently,however,important and great progress of SMSI-based synergetic effects has been made in electrocatalysis,such as electrocatalyst design and electrocatalytic mechanism investigations.To better understand the nature of the synergetic effect assisting the further development of electrocatalysts,a comprehensive and in-depth overview highlighting and discussing the recent advances of SMSI in electrocatalysis is necessary and highly desirable but still absent.Herein,this review firstly presents various strategies of designing and constructing composite catalysts featuring SMSI.Further from the perspectives of electrocatalysis,the characterization techniques towards the electron structure,local interfacial and morphological features and active sites for SMSI-based electrocatalysts,have been summarized in detail.Importantly,the recent advances in the design of single-and bi-functional electrocatalysts featuring SMSI-based synergetic catalytic effects,and the key roles of SMSI during the electrocatalytic reactions are emphasized.Finally,the challenges and prospects are discussed to highlight the key remaining issues in the future development of SMSI-based electrocatalysts.展开更多
The new technology of direct decomposition of H_(2)S into high value-added H_(2) and S,as an alternative to the Claus process in industry,is an ideal route that can not only deal with toxic and abundant H_(2)S waste g...The new technology of direct decomposition of H_(2)S into high value-added H_(2) and S,as an alternative to the Claus process in industry,is an ideal route that can not only deal with toxic and abundant H_(2)S waste gas but also recover clean energy H_(2),which has significant socio-economic and ecological advantages.However,the highly effective decomposition of H_(2)S at low temperatures is still a great challenge,because of the stringent thermodynamic equilibrium constraints(only 20% even at high temperature of 1010℃).Conventional microwave catalysts exhibit unsatisfactory performance at low temperatures(below 600℃).Herein,Mo_(2)C@CeO_(2) catalysts with a core-shell structure were successfully developed for robust microwave catalytic decomposition of H_(2)S at low temperatures.Two carbon precursors,para-phenylenediamine(Mo_(2)C-p)and meta-phenylenediamine(Mo_(2)C-m),were employed to tailor Mo_(2)C configurations.Remarkably,the H_(2)S conversion of Mo_(2)C-p@CeO_(2) catalyst at a low temperature of 550℃ is as high as 92.1%,which is much higher than the H_(2)S equilibrium conversion under the conventional thermal conditions(2.6% at 550℃).To our knowledge,this represents the most active catalyst for microwave catalytic decomposition of H_(2)S at low temperature of 550℃.Notably,Mo_(2)C-p demonstrated superior intrinsic activity(84%)compared to Mo_(2)C-m(6.4%),with XPS analysis revealing that its enhanced performance stems from a higher concentration of Mo_(2+)active sites.This work presents a substitute approach for the efficient utilization of H_(2)S waste gas and opens up a novel avenue for the rational design of microwave catalysts for microwave catalytic reaction at low-temperature.展开更多
Transforming industrial heritage will have internal economic and cultural effects and will also catalyse changes in surrounding urban areas.Transforming industrial heritage is therefore an essential part of strategies...Transforming industrial heritage will have internal economic and cultural effects and will also catalyse changes in surrounding urban areas.Transforming industrial heritage is therefore an essential part of strategies to regenerate decayed industrial districts.The aim of this study was to attempt to answer three questions.Can all transformed industrial heritage give catalytic effects?How should the potential for catalytic effects be assessed?What factors prevent catalytic effects?The Sanbao Street Industrial Heritage Historic District in Changzhou,China,was used as an example,and three effects catalysed by transforming industrial heritage were assessed.These were(1)reuse of industrial and non-industrial buildings in and near the historic district,(2)new construction in and near the historic district,and(3)revitalisation of the whole historic district.Failure of the catalytic effect caused by a lack of a conversion mechanism,failure to communicate the value of industrial heritage,and limited cultural industrial capacity was assessed.Formal transformation strategies focused on the connotative value of industrial heritage are proposed,and are expected to support future research and planning practices.展开更多
The catalytic effect of electrode materials is one of the most crucial factors for achieving efficient electrochemical energy conversion and storage.Carbon-based metal composites were widely synthesized and employed a...The catalytic effect of electrode materials is one of the most crucial factors for achieving efficient electrochemical energy conversion and storage.Carbon-based metal composites were widely synthesized and employed as electrode materials because of their inherited outstanding properties.Usually,electrode materials can provide a higher capacity than the anticipated values,even beyond the theoretical limit.The origin of the extra capacity has not yet been explained accurately,and its formation mechanism is still ambiguous.Herein,we first summarized the current research progress and drawbacks in energy storage devices(ESDs),and elaborated the role of catalytic effect in enhancing the performance of ESDs as follows:promoting the evolution of the solid electrolyte interphase(SEI),accelerating the reversible conversion of discharge/charge products,and improving the conversion speed of the intermediate and the utilization rate of the active materials,thereby avoiding the shuttling effect.Additionally,a particular focus was placed on the interaction between the catalytic effect and energy storage performance in order to highlight the efficacy and role of the catalytic effect.We hope that this review could provide innovative ideas for designing the electrode materials with an efficient catalytic effect for ESDs to promote the development of this research field.展开更多
Diphenylene was synthesized directly from benzene under the catalytic effect of GaP nanocrystals, and the effect of GaP nanocrystals content was studied. The experimental results showed that no reactions took place wi...Diphenylene was synthesized directly from benzene under the catalytic effect of GaP nanocrystals, and the effect of GaP nanocrystals content was studied. The experimental results showed that no reactions took place without GaP nanocrystals. The more the GaP nanocrystals added, the more the reaction complete. Furthermore, at high temperatures (450–480°C), when the content of GaP nanocrystals was high enough, almost all benzene polymerized and the yield of diphenylene was rather high. On the contrast, even if there are enough GaP nanocrystals in the reaction mixture, almost no polymerization reaction took place at low temperature (for example, 250–300°C), and the yield of diphenylene was very poor. The analytical results of XRD, IR, elemental analysis and NMR proved that the sample was truly diphenylene.展开更多
Lithium-sulfur (Li-S) batteries are considered appealing power sources due to their high theoretical energy density (2600 Wh kg-1), low cost, and environmental friendliness. However, their widespread applicability is ...Lithium-sulfur (Li-S) batteries are considered appealing power sources due to their high theoretical energy density (2600 Wh kg-1), low cost, and environmental friendliness. However, their widespread applicability is restricted by two scientific problems: sluggish sulfur reaction kinetics and severe polysulfide shuttle effects. Multifarious strategies have been developed to overcome these two obstacles and achieve high sulfur utilization and capacity retention. Among these strategies, the introduction of catalytic materials into the Li-S battery system can greatly accelerate sulfur conversion and effectively inhibit the polysulfide shuttle effects. Herein, we have comprehensively reviewed the recent progress of catalytic engineering for polysulfide conversion in high-performance lithium-sulfur batteries. First, various catalytic materials serve as sulfur hosts, functionalized separators, and electrolyte additives;the mechanisms by which these materials promote the conversion of polysulfides in Li-S batteries have been systematically summarized. The relationship of structure, preparation, property, advantages, and limitations of these catalytic materials are comprehensively presented. Subsequently, the advanced characterization techniques of these catalytic processes are discussed, shedding light on the fundamental understanding of catalytic effects for improved electrochemical performance. Furthermore, future design tactics for high-performance Li-S batteries are discussed.展开更多
The effects of peptides,amino acids and organic bases as an axial ligand on reaction ac- tivities in the electrocarboxylation of benzyl chloride with CO_2 catalyzed by CoTPP are reported. The imidazole organic base,pe...The effects of peptides,amino acids and organic bases as an axial ligand on reaction ac- tivities in the electrocarboxylation of benzyl chloride with CO_2 catalyzed by CoTPP are reported. The imidazole organic base,peptide containing —SH and amino acid containing imidazolyl en- hance the catalytic activity.The effect of imidazole amounts on the catalytic activity of CoTPP is studied.展开更多
Ag-based nanocatalysts exhibit good catalytic activity for the electrochemical reduction of organic halides. Ag-Ni alloy nanoparticles（NPs） were facilely prepared by chemical reduction, and the as-prepared nanocatal...Ag-based nanocatalysts exhibit good catalytic activity for the electrochemical reduction of organic halides. Ag-Ni alloy nanoparticles（NPs） were facilely prepared by chemical reduction, and the as-prepared nanocatalysts were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The electrocatalytic activity of Ag-Ni NPs for benzyl chloride reduction was studied in organic medium using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that the addition of Ni element can obviously decrease the size of Ag-Ni NPs, shift the reduction peak potential（φp） of benzyl chloride positively, and increase the catalytic activity of Ag-Ni NPs. However, when the Ni content reaches a certain value, the catalytic activity of Ag-Ni NPs decreases. Meanwhile, the synergistic catalytic effect of Ag-Ni NPs was also discussed.展开更多
Magnesium hydride(MgH_(2)),which possesses high hydrogen density of 7.6 wt%,abundant resource and non-toxicity,has captured intense attention as one of the potential hydrogen storage materials.However,the practical ap...Magnesium hydride(MgH_(2)),which possesses high hydrogen density of 7.6 wt%,abundant resource and non-toxicity,has captured intense attention as one of the potential hydrogen storage materials.However,the practical application of Mg/MgH_(2) system is suffering from high thermal stability,sluggish absorption and desorption kinetics.Herein,two-dimensional(2D) vanadium nanosheets(V_(NS)) were successfully prepared via a facile wet chemical ball milling method and proved to be highly effective on improving the hydrogen storage performance of MgH_(2).For instance,the MgH_(2)+7 wt% V_(NS) composite began to release hydrogen at 187.2℃,152 ℃ lower than that of additive-free MgH_(2).At 300℃,6.3 wt% hydrogen was released from the MgH_(2)+7 wt% V_(NS) composite within 10 min.In addition,the fully dehydrogenated sample could absorb hydrogen even at room temperature under hydrogen pressure of 3.2 MPa.X-ray diffractometer(XRD) and transmission electron microscopy(TEM)results confirmed metallic vanadium served as catalytic unit for facilitating the de/rehydrogenation reaction of MgH_(2).This finding presents an example of facile synthesis of two-dimensional(2D) vanadium with excellent catalysis,which may shed light on future design and preparation of highly effective layered catalysts for hydrogen storage and other energy-related areas.展开更多
The catalytic effect of K2SiF6 on MgH2 was first timely studied.The MgH2+5 wt.%K2SiF6 was prepared via the ball milling technique.The catalyst had lessened the initial decomposition temperature by 134℃ and 48℃ as co...The catalytic effect of K2SiF6 on MgH2 was first timely studied.The MgH2+5 wt.%K2SiF6 was prepared via the ball milling technique.The catalyst had lessened the initial decomposition temperature by 134℃ and 48℃ as compared to both pristine and milled MgH2 samples,respectively.In 2 minutes,4.5 wt.%of hydrogen was absorbed(250℃)by the doped composite,which was 0.8 wt.%higher than the milled MgH2.Meanwhile,for the desorption kinetics(320℃,1 atm),the amount of desorbed hydrogen was increased by 2.4 wt.%and 2.3 wt.%for the first 10 and 20 minutes.Besides,contracting volume and Johnson-Mehl-Avrami models were used to analyse the kinetics sorptions.The decomposition activation energy calculated based on Kissinger equation was 114 kJ/mol.As for the active species,Mg2Si,MgF2 and KH were formed during the heating process.These active species are speculated to be responsible for the improvement of the hydrogenation properties of the composite.展开更多
A new kinetic spectrophotometric method is developed for the measurement of manganese(Ⅱ) in water. The method is based on the catalytic effect of manganese(Ⅱ) with the oxidation of weak acid brilliant blue dye(RAWL)...A new kinetic spectrophotometric method is developed for the measurement of manganese(Ⅱ) in water. The method is based on the catalytic effect of manganese(Ⅱ) with the oxidation of weak acid brilliant blue dye(RAWL) by KIO4 using the Nitrilo triacetic acid(NTA) as an activation reagent. The optimum conditions obtained are 40 mgL-1 RAWL,1×10-4molL-1 KIO4,2×10-4 molL-1 Nitrilo triacetic acid(NTA),pH = 5.8,the reaction time of 3.00 min and the temperature of 20.0 ℃. Under the optimum conditions,the proposed method allows the measurement of manganese(Ⅱ) in a range of 0-50.0 ng mL-1 and with a detection limit of down to 0.158 ng mL-1. The recovery efficiency in measuring the standard manganese(Ⅱ) solution is in a range of 98.5%-102%,and the RSD is in a range of 0.76%-1.25%. The new method has been successfully applied to the measurement of manganese(Ⅱ) in both fresh water and seawater samples with satisfying results. Moreover,few cations and anions interfere with the measurement of manganese(Ⅱ). Compared with other kinetic catalytic methods and instrumental methods,the proposed method shows fairly good selectivity and sensitivity,low cost,cheapness,low detection limit and rapidity. It can be applied on boats easily.展开更多
基金supported by the National Natural Science Foundation of China(52272194)Liaoning Revitalization Talents Program(XLYC2007155)。
文摘Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical capacity.Toward the broader implementation,the primary obstacle lies in the intricate multi-electron,multi-step redox reaction associated with sluggish conversion kinetics,subsequently giving rise to a cascade of parasitic issues.In order to smooth reaction kinetics,catalysts are widely introduced to accelerate reaction rate via modulating the energy barrier.Over past decades,a large amount of research has been devoted to the catalyst design and catalytic mechanism exploration,and thus the great progress in electrochemical performance has been realized.Therefore,it is necessary to make a comprehensive review toward key progress in catalyst design and future development pathway.In this review,the basic mechanism of lithium metal batteries is provided along with corresponding advantages and existing challenges detailly described.The main catalysts employed to accelerate cathode reaction with emphasis on their catalytic mechanism are summarized as well.Finally,the rational design and innovative direction toward efficient catalysts are suggested for future application in metal-sulfur/gas battery and beyond.This review is expected to drive and benefit future research on rational catalyst design with multi-parameter synergistic impacts on the activity and stability of next-generation metal battery,thus opening new avenue for sustainable solution to climate change,energy and environmental issues,and the potential industrial economy.
文摘The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.
基金supported by the National Key R&D Program of China(No.2021YFB3802400)the National Natural Sci-ence Foundation of China(Nos.22279020,22109026,51971065,51901045,U2130208,and 52071156)the Science and Technology Commission of Shanghai Municipality(Nos.21ZR1407500 and 23ZR1406500).
文摘Lithium borohydride(LiBH_(4))is regarded as a potential hydrogen storage material due to its high gravi-metric and volumetric capacity,but its practical application suffers from high operating temperature and poor reversibility.Herein,porous hollow carbon microspheres composed of carbon-coated Ni nanoparti-cles with high content(denoted as Ni/C)are rationally designed as functional support,which not only induces effective nanoconfinement of LiBH4 but also promotes efficiently homogeneous destabilization reaction between LiBH4 and Ni nanoparticles.The introduction of Ni nanoparticles leads to the decrease of the Gibbs free energy change for H_(2)desorption of LiBH4 based on the formation of Ni_(2)B down to−0.95 eV while this value reaches 1.19 eV for bulk LiBH4,validating the effective role of Ni in thermo-dynamically destabilizing H_(2)desorption.Impressively,the average B-H bond length of LiBH4 on Ni_(2)B reaches 1.291A and thus the corresponding dissociation energy of removing one H atom from LiBH4 is lowered to 1.00 eV,much lower than bulk LiBH4(4.22 eV)and even LiBH4 on Ni(1.27 eV),which verifies superior role of Ni_(2)B than Ni in catalytically enhancing H_(2)desorption.Therefore,a capacity of 8.86 wt.%is obtained for LiBH4 confined into Ni/C at 320℃ after 10 cycles.
基金Supported by the National Natural Science Foundation of China （50306008, 50602024）.
文摘The monodispersed Co nanoparticles were successfully prepared by means of hydrogen plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by transmission electron microscopy （TEM）, BET equation, X-ray diffraction （XRD）, and the corresponding selected area electron diffraction （SAED）. The catalytic effect of Co nanoparticles on the decomposition of ammonium perchlorate （AP） was investigated by differential thermal analyzer （DTA）. Compared with the thermal decomposition of pure AP, the addition of Co nanoparticles （2%-10%, by mass） decreases the decomposition temperature of AP by 145.01-155.72℃. Compared with Co3O4 nano-particles and microsized Co particles, the catalytic effect of Co nanoparticles for AP is stronger. Such effect is attributed to the large specific surface area and its interaction of Co with decomposition intermediate gases. The present work provides useful information for the application of Co nanoparficles in the AP-based propellant.
基金financially supported by the Natural Science Foundation of Hebei Province(No.E2013402004)
文摘By transition metals （Fe, Ni, Mn, Co） and their alloys as catalysts during the diamond synthesis, some transition phases will be formed, such as FeaC type carbides and y solid solutions. Based on the empirical electron theory of the solid and molecules, the valence electron structures of different kinds of carbides and y solid solutions and the relative electron density differences of various diamond/carbide and y solid solution/carbide interfaces were calculated and analyzed in this paper. The electron structure conditions of the ideal catalyst were presented by analyzing the different catalytic effects of the catalysts, which provide a new theoretical path to the optimal design of the catalyst composition
基金National Natural Science Foundation of China(Nos.20576079,20776159)
文摘Catalysis and regeneration efficiency of granular activated carbon （GAC） and activated carbon fiber （ACF） were investigated in a non-equilibrium plasma water treatment reactor with a combination of pulsed streamer discharge and GAC or ACF. The experimental results show that the degradation efficiency of methyl orange （MO） by the combined treatment can increase 22% （for GAC） and 24% （for ACF） respectively compared to pulsed discharge treatment alone, indicating that the combined treatment has a synergetic effect. The MO degradation efficiency by the combined treatment with pulsed discharge and saturated GAC or ACF can increase 12% and 17% respectively compared to pulsed discharge treatment alone. Both GAC and ACF show catalysis and the catalysis of ACF is prominent. Meanwhile, the regeneration of GAC and ACF are realized in this process. When H202 is introduced into the system, the utilization efficiency of ozone and ultraviolet light is improved and the regeneration efficiency of GAC and ACF is also increased.
文摘The preparation method of H_4MoO_(26)-polyaniline film modified electrode and its voltammetric behaviour are described. The modified electrode has high electrocatalytic activity on chlorate ions.
基金theStateKeyLab .forPhys .Chem .ofSolidSur face XiamenUniversity
文摘The electrodeposition of zinc nickle alloy was obtained on a copper cathode of 1×1cm 2. The deposited alloys are quantitatively analyzed by atomic absorption spectrometry. The morphology of the deposits was observed by means of scanning electron microscopy(SEM).We observed that the electrodeposition of zinc nickle alloy is an anomalous codeposition. The catalytic effects of SCN - on the electrochemical behavior of Ni deposition and hydrogen discharge are obvious. SEM analysis shows that the surface morphology of the coating appears to be more compact and homogeneous with the increase of SCN - concentration.
文摘Kinetics of carbothermic reduction of manganese oxide and the catalyticeffect of La_2O_3 on the reduction have been studied by the measurement of mass loss in N_2atmosphere at different temperatures and followed by SEM analysis. It is concluded that the kineticsof carbothermic reduction of manganese oxide is divided into three stages: gas diffusioncontrolling stage, carbon gasification con-trolling stage and solid state diffusion controllingstage. La_2O_3 has catalytic effect on the reduction. The catalytic effect of La_2O_3 increases withthe added amount of La_2O_3. SEM analysis shows that the catalytic mechanism is that La_2O_3promotes the transfer of oxygen ions so that carbon gasifying is catalyzed and thus carbothermicreduction of MnO_2 is catalyzed.
基金supported by National Key R&D Program of China(2022YFB4002700)Shanghai Science and Technology Committee Rising-Star Program(22QA1403400)the Natural Science Foundation of Shanghai(21ZR1418700).
文摘Strong metal–support interaction(SMSI),namely the strong electronic and structural interaction between metal nanoparticles and supports,one of the most typical synergetic catalytic effects in composite catalysts,has been found critically important in the design of catalyst for thermocatalysis in the past.Recently,however,important and great progress of SMSI-based synergetic effects has been made in electrocatalysis,such as electrocatalyst design and electrocatalytic mechanism investigations.To better understand the nature of the synergetic effect assisting the further development of electrocatalysts,a comprehensive and in-depth overview highlighting and discussing the recent advances of SMSI in electrocatalysis is necessary and highly desirable but still absent.Herein,this review firstly presents various strategies of designing and constructing composite catalysts featuring SMSI.Further from the perspectives of electrocatalysis,the characterization techniques towards the electron structure,local interfacial and morphological features and active sites for SMSI-based electrocatalysts,have been summarized in detail.Importantly,the recent advances in the design of single-and bi-functional electrocatalysts featuring SMSI-based synergetic catalytic effects,and the key roles of SMSI during the electrocatalytic reactions are emphasized.Finally,the challenges and prospects are discussed to highlight the key remaining issues in the future development of SMSI-based electrocatalysts.
基金supported by the National Natural Science Foundation of China(22178295,21706225)Natural Science Foundation of Hunan Province(2025JJ50085)Hunan Collaborative Innovation Center of New Chemical Technologies for Environmental Benignity and Efficient Resource Utilization.
文摘The new technology of direct decomposition of H_(2)S into high value-added H_(2) and S,as an alternative to the Claus process in industry,is an ideal route that can not only deal with toxic and abundant H_(2)S waste gas but also recover clean energy H_(2),which has significant socio-economic and ecological advantages.However,the highly effective decomposition of H_(2)S at low temperatures is still a great challenge,because of the stringent thermodynamic equilibrium constraints(only 20% even at high temperature of 1010℃).Conventional microwave catalysts exhibit unsatisfactory performance at low temperatures(below 600℃).Herein,Mo_(2)C@CeO_(2) catalysts with a core-shell structure were successfully developed for robust microwave catalytic decomposition of H_(2)S at low temperatures.Two carbon precursors,para-phenylenediamine(Mo_(2)C-p)and meta-phenylenediamine(Mo_(2)C-m),were employed to tailor Mo_(2)C configurations.Remarkably,the H_(2)S conversion of Mo_(2)C-p@CeO_(2) catalyst at a low temperature of 550℃ is as high as 92.1%,which is much higher than the H_(2)S equilibrium conversion under the conventional thermal conditions(2.6% at 550℃).To our knowledge,this represents the most active catalyst for microwave catalytic decomposition of H_(2)S at low temperature of 550℃.Notably,Mo_(2)C-p demonstrated superior intrinsic activity(84%)compared to Mo_(2)C-m(6.4%),with XPS analysis revealing that its enhanced performance stems from a higher concentration of Mo_(2+)active sites.This work presents a substitute approach for the efficient utilization of H_(2)S waste gas and opens up a novel avenue for the rational design of microwave catalysts for microwave catalytic reaction at low-temperature.
文摘Transforming industrial heritage will have internal economic and cultural effects and will also catalyse changes in surrounding urban areas.Transforming industrial heritage is therefore an essential part of strategies to regenerate decayed industrial districts.The aim of this study was to attempt to answer three questions.Can all transformed industrial heritage give catalytic effects?How should the potential for catalytic effects be assessed?What factors prevent catalytic effects?The Sanbao Street Industrial Heritage Historic District in Changzhou,China,was used as an example,and three effects catalysed by transforming industrial heritage were assessed.These were(1)reuse of industrial and non-industrial buildings in and near the historic district,(2)new construction in and near the historic district,and(3)revitalisation of the whole historic district.Failure of the catalytic effect caused by a lack of a conversion mechanism,failure to communicate the value of industrial heritage,and limited cultural industrial capacity was assessed.Formal transformation strategies focused on the connotative value of industrial heritage are proposed,and are expected to support future research and planning practices.
基金the National Natural Science Foundation of China(21875221,21890753,22162026,22225204,and U1967215)the National Key Research and Development Program of China(2016YFB0101202)+2 种基金the Youth Talent Support Program of High-Level Talents Special Support Plan in Henan Province(ZYQR201810148)Qiushi Scientific Research Initiation Plan of Zhengzhou University(32213243)the Distinguished Young Scholars Innovation Team of Zhengzhou University(32320275).
文摘The catalytic effect of electrode materials is one of the most crucial factors for achieving efficient electrochemical energy conversion and storage.Carbon-based metal composites were widely synthesized and employed as electrode materials because of their inherited outstanding properties.Usually,electrode materials can provide a higher capacity than the anticipated values,even beyond the theoretical limit.The origin of the extra capacity has not yet been explained accurately,and its formation mechanism is still ambiguous.Herein,we first summarized the current research progress and drawbacks in energy storage devices(ESDs),and elaborated the role of catalytic effect in enhancing the performance of ESDs as follows:promoting the evolution of the solid electrolyte interphase(SEI),accelerating the reversible conversion of discharge/charge products,and improving the conversion speed of the intermediate and the utilization rate of the active materials,thereby avoiding the shuttling effect.Additionally,a particular focus was placed on the interaction between the catalytic effect and energy storage performance in order to highlight the efficacy and role of the catalytic effect.We hope that this review could provide innovative ideas for designing the electrode materials with an efficient catalytic effect for ESDs to promote the development of this research field.
基金the National Natural ScienceFoundation of China (Grant No. 60025409), the Fund for the Excellent Young Scientists in Shandong Province and the Fund for University Key Teacher by the Ministry of Education of China.
文摘Diphenylene was synthesized directly from benzene under the catalytic effect of GaP nanocrystals, and the effect of GaP nanocrystals content was studied. The experimental results showed that no reactions took place without GaP nanocrystals. The more the GaP nanocrystals added, the more the reaction complete. Furthermore, at high temperatures (450–480°C), when the content of GaP nanocrystals was high enough, almost all benzene polymerized and the yield of diphenylene was rather high. On the contrast, even if there are enough GaP nanocrystals in the reaction mixture, almost no polymerization reaction took place at low temperature (for example, 250–300°C), and the yield of diphenylene was very poor. The analytical results of XRD, IR, elemental analysis and NMR proved that the sample was truly diphenylene.
基金financially supported by National Natural Science Foundation of China(Nos.52164030 and 22179055)Natural Science Foundation of Jiangxi Province(Nos.20202ACBL204007 and 20224BAB204004)Program of Qingjiang Excellent Young Talents of Jiangxi University of Science and Technology(No.JXUSTQJYX2019010).
文摘Lithium-sulfur (Li-S) batteries are considered appealing power sources due to their high theoretical energy density (2600 Wh kg-1), low cost, and environmental friendliness. However, their widespread applicability is restricted by two scientific problems: sluggish sulfur reaction kinetics and severe polysulfide shuttle effects. Multifarious strategies have been developed to overcome these two obstacles and achieve high sulfur utilization and capacity retention. Among these strategies, the introduction of catalytic materials into the Li-S battery system can greatly accelerate sulfur conversion and effectively inhibit the polysulfide shuttle effects. Herein, we have comprehensively reviewed the recent progress of catalytic engineering for polysulfide conversion in high-performance lithium-sulfur batteries. First, various catalytic materials serve as sulfur hosts, functionalized separators, and electrolyte additives;the mechanisms by which these materials promote the conversion of polysulfides in Li-S batteries have been systematically summarized. The relationship of structure, preparation, property, advantages, and limitations of these catalytic materials are comprehensively presented. Subsequently, the advanced characterization techniques of these catalytic processes are discussed, shedding light on the fundamental understanding of catalytic effects for improved electrochemical performance. Furthermore, future design tactics for high-performance Li-S batteries are discussed.
文摘The effects of peptides,amino acids and organic bases as an axial ligand on reaction ac- tivities in the electrocarboxylation of benzyl chloride with CO_2 catalyzed by CoTPP are reported. The imidazole organic base,peptide containing —SH and amino acid containing imidazolyl en- hance the catalytic activity.The effect of imidazole amounts on the catalytic activity of CoTPP is studied.
基金Projects(2127106951238002+3 种基金J1210040J1103312)supported by the National Natural Science Foundation of ChinaProject(2013GK3015)supported by the Science and Technology Project of Hunan ProvinceChina
文摘Ag-based nanocatalysts exhibit good catalytic activity for the electrochemical reduction of organic halides. Ag-Ni alloy nanoparticles（NPs） were facilely prepared by chemical reduction, and the as-prepared nanocatalysts were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The electrocatalytic activity of Ag-Ni NPs for benzyl chloride reduction was studied in organic medium using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that the addition of Ni element can obviously decrease the size of Ag-Ni NPs, shift the reduction peak potential（φp） of benzyl chloride positively, and increase the catalytic activity of Ag-Ni NPs. However, when the Ni content reaches a certain value, the catalytic activity of Ag-Ni NPs decreases. Meanwhile, the synergistic catalytic effect of Ag-Ni NPs was also discussed.
基金financially supported by the National Natural Science Foundation of China(No.51801078)the Natural Science Foundation of Jiangsu Province(No.BK20180986)。
文摘Magnesium hydride(MgH_(2)),which possesses high hydrogen density of 7.6 wt%,abundant resource and non-toxicity,has captured intense attention as one of the potential hydrogen storage materials.However,the practical application of Mg/MgH_(2) system is suffering from high thermal stability,sluggish absorption and desorption kinetics.Herein,two-dimensional(2D) vanadium nanosheets(V_(NS)) were successfully prepared via a facile wet chemical ball milling method and proved to be highly effective on improving the hydrogen storage performance of MgH_(2).For instance,the MgH_(2)+7 wt% V_(NS) composite began to release hydrogen at 187.2℃,152 ℃ lower than that of additive-free MgH_(2).At 300℃,6.3 wt% hydrogen was released from the MgH_(2)+7 wt% V_(NS) composite within 10 min.In addition,the fully dehydrogenated sample could absorb hydrogen even at room temperature under hydrogen pressure of 3.2 MPa.X-ray diffractometer(XRD) and transmission electron microscopy(TEM)results confirmed metallic vanadium served as catalytic unit for facilitating the de/rehydrogenation reaction of MgH_(2).This finding presents an example of facile synthesis of two-dimensional(2D) vanadium with excellent catalysis,which may shed light on future design and preparation of highly effective layered catalysts for hydrogen storage and other energy-related areas.
基金the Universiti Malaysia Terengganu(UMT)through the Golden Goose Research Grant(GGRG)(VOT 55190).
文摘The catalytic effect of K2SiF6 on MgH2 was first timely studied.The MgH2+5 wt.%K2SiF6 was prepared via the ball milling technique.The catalyst had lessened the initial decomposition temperature by 134℃ and 48℃ as compared to both pristine and milled MgH2 samples,respectively.In 2 minutes,4.5 wt.%of hydrogen was absorbed(250℃)by the doped composite,which was 0.8 wt.%higher than the milled MgH2.Meanwhile,for the desorption kinetics(320℃,1 atm),the amount of desorbed hydrogen was increased by 2.4 wt.%and 2.3 wt.%for the first 10 and 20 minutes.Besides,contracting volume and Johnson-Mehl-Avrami models were used to analyse the kinetics sorptions.The decomposition activation energy calculated based on Kissinger equation was 114 kJ/mol.As for the active species,Mg2Si,MgF2 and KH were formed during the heating process.These active species are speculated to be responsible for the improvement of the hydrogenation properties of the composite.
文摘A new kinetic spectrophotometric method is developed for the measurement of manganese(Ⅱ) in water. The method is based on the catalytic effect of manganese(Ⅱ) with the oxidation of weak acid brilliant blue dye(RAWL) by KIO4 using the Nitrilo triacetic acid(NTA) as an activation reagent. The optimum conditions obtained are 40 mgL-1 RAWL,1×10-4molL-1 KIO4,2×10-4 molL-1 Nitrilo triacetic acid(NTA),pH = 5.8,the reaction time of 3.00 min and the temperature of 20.0 ℃. Under the optimum conditions,the proposed method allows the measurement of manganese(Ⅱ) in a range of 0-50.0 ng mL-1 and with a detection limit of down to 0.158 ng mL-1. The recovery efficiency in measuring the standard manganese(Ⅱ) solution is in a range of 98.5%-102%,and the RSD is in a range of 0.76%-1.25%. The new method has been successfully applied to the measurement of manganese(Ⅱ) in both fresh water and seawater samples with satisfying results. Moreover,few cations and anions interfere with the measurement of manganese(Ⅱ). Compared with other kinetic catalytic methods and instrumental methods,the proposed method shows fairly good selectivity and sensitivity,low cost,cheapness,low detection limit and rapidity. It can be applied on boats easily.
