Direct conversion of syngas to light olefins(STO)on bifunctional catalysts has garnered significant attention,yet a comprehensive understanding of the reaction pathway and reaction kinetics remains elusive.Herein,we t...Direct conversion of syngas to light olefins(STO)on bifunctional catalysts has garnered significant attention,yet a comprehensive understanding of the reaction pathway and reaction kinetics remains elusive.Herein,we theoretically addressed the kinetics of the direct STO reaction on typical ZnAl_(2)O_(4)/zeolite catalysts by establishing a complete reaction network,consisting of methanol synthesis and conversion,water gas shift(WGS)reaction,olefin hydrogenation,and other relevant steps.The WGS reaction occurs very readily on ZnAl_(2)O_(4) surface whereas which is less active towards alkane formation via olefin hydrogenation,and the latter can be attributed to the characteristics of the H_(2) heterolytic activation and the weak polarity of olefins.The driving effect of zeolite component towards CO conversion was demonstrated by microkinetic simulations,which is sensitive to reaction conditions like space velocity and reaction temperature.Under a fixed ratio of active sites between oxide and zeolite components,the concept of the“impossible trinity”of high CO conversion,high olefin selectivity,and high space velocity can thus be manifested.This work thus provides a comprehensive kinetic picture on the direct STO conversion,offering valuable insights for the design of each component of bifunctional catalysts and the optimization of reaction conditions.展开更多
The purpose of this study is to develop novel P-Mo-V heteropoly compound catalysts for the oxidation of methacrolein to methacrylic acid.The introduction of Cu,as a modifying element,was employed to enhance the cataly...The purpose of this study is to develop novel P-Mo-V heteropoly compound catalysts for the oxidation of methacrolein to methacrylic acid.The introduction of Cu,as a modifying element,was employed to enhance the catalytic performance.Experimental results show that the addition of Cu significantly improved the catalyst performance,increasing the conversion rate of methacrolein from 17.2%to 84.2%,while the yield of methacrylic acid was boosted from 5.5%to 51.7%.A series of characterization results showed that both P-Mo-V and Cu-P-Mo-V catalysts primarily exhibited the crystal phase of[PMo_(12)O_(40)]^(3−),with a small amount of[PMo_(11)VO_(40)]^(3−)phase.However,the Cu-P-Mo-V catalyst exhibited much better oxidation–reduction ability compared to the P-Mo-V catalyst.Isolated Cu atoms were found to exist in a highly decentralized tetrahedral coordination structure,bridged by oxygen atoms within the heteropoly compound framework.The addition of Cu resulted in notable alterations in the modulation of the surface electronic structure,enhancement of oxidation–reduction ability,and optimization of the reaction pathway,thereby improving the overall catalytic activity of the catalyst.This study not only provides new insights into the modification of P-Mo-V heteropoly compound catalysts but also lays a foundation for understanding their catalytic mechanisms in organic synthesis reactions,demonstrating the potential of modifying elements in improving catalyst performance.展开更多
The distributions of framework aluminum(Al)in zeolites critically govern the location and speciation of active copper(Cu)centers,thereby influencing their performance in ammonia selective catalytic reduction(NH_(3)-SC...The distributions of framework aluminum(Al)in zeolites critically govern the location and speciation of active copper(Cu)centers,thereby influencing their performance in ammonia selective catalytic reduction(NH_(3)-SCR)of nitrogen oxides(NO_(x)).Conventional Cu-SSZ-39(Cu-SSZ-39-T)exhibits excellent hydrothermal stability but limited low-temperature activity(150–225℃)due to a low concentration of Al in 8-membered rings(8MRs)that inhibits the formation of active[Cu(OH)]^(+)-Z species.Herein,an SSZ-39 zeolite synthesized with potassium ions(SSZ-39-K)achieved a significantly higher 8MR Al fraction(37.6%).Density functional theory calculations and H_(2)-temperature-programmed reduction analyses confirmed that the increased 8MR Al population facilitated the formation of[Cu(OH)]^(+)-Z species.Aged Cu-SSZ-39-K exhibited nearly twice the NO_(x)conversion of aged Cu-SSZ-39-T in the 150–225℃range while maintaining comparable high-temperature activity(250–550℃)under a gas hourly space velocity of 250,000 h^(-1).Enhanced low-temperature performance is particularly beneficial for mitigating NO_(x)emissions during cold-start phase.Moreover,SSZ-39-K was synthesized with a high crystallization yield(~65%),nearly double the highest yield(33%)reported for direct synthesis routes.This work establishes a robust strategy for tailoring Al distributions in SSZ-39 zeolites,offering an effective pathway to improve low-temperature NH_(3)-SCR performance and promote practical implementation.展开更多
A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the...A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the structure-directing agent for the MWW layered structure;and dicyclohexylamine(DCHA),in the role of an in-situ delaminating agent.By varying the amount of DCHA,partially and fully delaminated MWW zeolites having two MWW structure layers and one single layer,respectively,were obtained.These were denoted as SCM-1(Sinopec Composite Material)and SCM-6,respectively.The delaminated materials possess ultra-large external surface areas,and the transmission electron microscopy images illustrated their layered nature.In the reaction of liquid phase benzene alkylation with ethylene,SCM-1,the double-layered MWW zeolite,exhibited far superior catalytic performance compared to zeolite MCM-22.展开更多
The alkylation of benzene with isopropanol over beta-zeolite is a more cost-effective solution to cumene production. During the benzene alkylation cycles, the cumene selectivity slowly increased, while the benzene con...The alkylation of benzene with isopropanol over beta-zeolite is a more cost-effective solution to cumene production. During the benzene alkylation cycles, the cumene selectivity slowly increased, while the benzene conversion presented the sharp decrease due to catalyst deactivation. The deactivation mechanism of betazeolite catalyst was investigated by characterizing the fresh and used catalysts. The XRD, SEM and TEM results show that the crystalline and particle size of the beta-zeolite catalyst almost remained stable during the alkylation cycles. The drop in catalytic activity and benzene conversion could be explained by the TG, BET,NH_3-TPD and GC–MS results. The organic matters mainly consisted of ethylbenzene, p-xylene and 1-ethyl-3-(1-methyl) benzene produced in the benzene alkylation deposited in the catalyst, which strongly reduced the specific surface area of beta-zeolite catalyst. Moreover, during the reaction cycles, the amount of acidity also significantly decreased. As a result, the catalyst deactivation occurred. To maintain the catalytic performance,the catalyst regeneration was carried out by using ethanol rinse and calcination. The deactivated catalyst could be effectively regenerated by the calcination method and the good catalytic performance was obtained.展开更多
Four ZSM-5 zeolite catalysts with different Si/Al ratios for the catalytic cracking of C4 fractions to produce ethylene and propylene were prepared in this study.First,the adsorption isotherms of pure n-butane and but...Four ZSM-5 zeolite catalysts with different Si/Al ratios for the catalytic cracking of C4 fractions to produce ethylene and propylene were prepared in this study.First,the adsorption isotherms of pure n-butane and butene-1 and their mixtures on these catalysts at 300K and p=0—100kPa were measured using the intelligent gra- vimetric analyzer.The experimental results indicate that the presence of Al can significantly affect the adsorption of butene-1 than that of n-butane on ZSM-5 zeolites.Then,the double Langmuir(DL)model was applied to study the pure gas adsorption on ZSM-5 zeolites for pure n-butane and butene-1.By combining the DL model with the ideal adsorbed solution theory(IAST),the IAST-DL model was applied to model the butene-1(1)/n-butane(2)binary mixture adsorption on ZSM-5 zeolites with different Si/Al ratios.The calculated results are in good agreement with the experimental data,indicating that the IAST-DL model is effective for the present systems.Finally,the adsorp- tion over a wide range of variables was predicted at low pressure and 300K by the model proposed.It is found that the selectivity of butene-1 over n-butane increases linearly with the decrease of Si/Al ratio.A correlation between the selectivity and Si/Al ratio of the sample was proposed at 300K and p=0.08MPa.展开更多
Selectivity control is a difficult scientific and industrial challenge in methanol-to-olefins(MTO)conversion.It has been experimentally established that the topology of zeolite catalysts influenced the distribution of...Selectivity control is a difficult scientific and industrial challenge in methanol-to-olefins(MTO)conversion.It has been experimentally established that the topology of zeolite catalysts influenced the distribution of products.Besides the topology effect on reaction kinetics,the topology influences the diffusion of reactants and products in catalysts as well.In this work,by using COMPASS force-field molecular dynamics method,we investigated the intracrystalline diffusion of ethene and propene in four different zeolites,CHA,MFI,BEA and FAU,at different temperatures.The self-diffusion coefficients and diffusion activation barriers were calculated.A strong restriction on the diffusion of propene in CHA was observed because the self-diffusion coefficient ratio of ethene to propene is larger than 18 and the diffusion activation barrier of propene is more than 20 kJ/mol in CHA.This ratio decreases with the increase of temperature in the four investigated zeolites.The shape selectivity on products from diffusion perspective can provide some implications on the understanding of the selectivity difference between HSAPO-34 and HZSM-5 catalysts for the MTO conversion.展开更多
NASICON-type Na_(3)V_(2)(PO_(4))_(3) is a promising electrode material for developing advanced sodium-ion batteries.Preparing Na_(3)V_(2)(PO_(4))_(3) with good performance by a cost-effective and large-scale method is...NASICON-type Na_(3)V_(2)(PO_(4))_(3) is a promising electrode material for developing advanced sodium-ion batteries.Preparing Na_(3)V_(2)(PO_(4))_(3) with good performance by a cost-effective and large-scale method is significant for industrial applications.In this work,a porous Na_(3)V_(2)(PO_(4))_(3)/C cathode material with excellent electrochemical performance is successfully prepared by an agar-gel combined with freeze-drying method.The Na_(3)V_(2)(PO_(4))_(3)/C cathode displayed specific capacities of 113.4 mAh·g^(-1),107.0 mAh·g^(-1) and 87.1 mAh·g^(-1) at 0.1 C,1 C and 10 C,respectively.For the first time,the 500-mAh soft-packed symmetrical sodium-ion batteries based on Na_(3)V_(2)(PO_(4))_(3)/C electrodes are successfully fabricated.The 500-mAh symmetrical batteries exhibit outstanding low temperature performance with a capacity retention of 83%at 0℃ owing to the rapid sodium ion migration ability and structural stability of Na_(3)V_(2)(PO_(4))_(3)/C.Moreover,the thermal runaway features are revealed by accelerating rate calorimetry(ARC)test for the first time.Thermal stability and safety of the symmetrical batteries are demonstrated to be better than lithium-ion batteries and some reported sodium-ion batteries.Our work makes it clear that the soft-packed symmetrical sodium ion batteries based on Na_(3)V_(2)(PO_(4))_(3)/C have a prospect of practical application in high safety requirement fields.展开更多
The microstructure, electrical properties, and density of Dy2O3-doped ZnO-based varistor ceramics, prepared using high-energy ball milling （HEBM） and sintered at 800℃, were investigated by increasing the cooling ra...The microstructure, electrical properties, and density of Dy2O3-doped ZnO-based varistor ceramics, prepared using high-energy ball milling （HEBM） and sintered at 800℃, were investigated by increasing the cooling rate in the order of H （slow cooling in furnace） → L （cooling in furnace） → K （cooling in air）. With the increase in cooling rate, the grain size and density decreased, the breakdown voltage （VImA/mm） increased, and the nonlinear coefficient （α） and leakage current （IL） exhibited extremum. The sample with the cooling type L showed the best properties with the breakdown voltage of 2650 V/ram, o：of 20.3, IL of 5.2 laA, and density of 5.42 g/cm^3. The barrier height （ФB）, donor concentration （Nd）, density of the interface states （Nd）, and barrier width （ω） all exhibited extremum during the alteration in cooling rate. The different relative amount of Bi-rich phase and its distribution as well as the characteristic parameters of grain boundary, resulting from the alteration of cooling rate, led to the changes in the properties of varistor ceramics.展开更多
In this work, a series of Ni-Mo-Mg-O catalysts with mesoporous structure prepared by sol-gel method were investigated for the oxidative dehydrogenation of propane （ODHP）. The techniques of temperature-programmed red...In this work, a series of Ni-Mo-Mg-O catalysts with mesoporous structure prepared by sol-gel method were investigated for the oxidative dehydrogenation of propane （ODHP）. The techniques of temperature-programmed reduction with H2 （H2-TPR）, N2 adsorption-desolption, Fourier transform infrared spectroscopy （FT-IR）, X-ray diffraction （XRD） and X-ray photoelectron spectra （XPS） were employed for catalyst characterization. It is found that the activity of the catalysts for ODHP increases first and then decreases with the increase of Mo content. The catalyst with a Mo/Ni atomic ratio of 1/1 exhibits the best catalytic activity, which gives the propene selectivity of 81.4% at a propane conversion of 11.3% under 600 ~C and maintains the good catalytic performance for 22 h on stream. This is related not only to its high reducibility and dispersion as revealed by TPR and XRD, but also to the formation of more selective oxygen species on the MoOz-NiO interface as identified by XPS.展开更多
Catalysis is one of the most cross-cutting technologies in the chemical industry, intensely influenc-ing our daily society. Its practical application is closely related to the engineering disciplines. At present, the ...Catalysis is one of the most cross-cutting technologies in the chemical industry, intensely influenc-ing our daily society. Its practical application is closely related to the engineering disciplines. At present, the academic and industrial research on catalysis in our country has made great break-throughs in fields like hydrocarbon production, oil-quality upgrading processes, green chemical engineering, and other energy and chemical users of catalysis. In this paper, we attempt to summa-rize the industrial catalysis achievements and present a discussion on the direction and the devel-opment strategy for catalysis, based on economic and social demands.展开更多
The effective valuation of catalyst supports in the catalytic oxidation makes the contribution to understand the support effect of great interest.Here,the role of active substrate in the performance and stability of C...The effective valuation of catalyst supports in the catalytic oxidation makes the contribution to understand the support effect of great interest.Here,the role of active substrate in the performance and stability of CuFe-Co ternary oxides was studied towards the complete catalytic oxidation of CO.The Cu-Fe-Co oxide thin films were deposited on copper grid mesh(CUGM)using one-step pulsed-spray evaporation chemical vapor deposition method.Crystalline structure and morphology analyses revealed nano-crystallite sizes and do me-top-like morphology.Synergistic effects between Cu,Fe and Co,which affect the surface Cu^2+,Fe^3+,Co^3+and chemisorbed oxygen species(O2 and OH)of thin films over the active support and thus result in better reducibility.The thin film catalysts supported on CUGM exhibited attractive catalytic activity compared to the te rnary oxides supported on ine rt grid mesh at a high gas hourly space velocity.Moreove r,the stability in time-on-stream of the ternary oxides on CUGM was evaluated in the CO oxidation for 30 h.The ad opted deposition strategy ofternary oxides on CUGM presents an excessive amount of adsorbed active oxygen species that play an impo rtant role in the complete CO oxidation.The catalysts supported on CUGM showed better catalytic conve rsion than that on inert grid mesh and some literature-reported noble metal oxides as well as transition metal oxides counterparts,revealing the beneficial effect of the CUGM suppo rt in the improvement of the catalytic performance.展开更多
The reaction mechanism of zeolite- or zeotype-catalyzed methanol-to-olefins（MTO） conversion is still a subject of debate. Employing periodic density functional theory calculations, the olefin-based cycle was studied...The reaction mechanism of zeolite- or zeotype-catalyzed methanol-to-olefins（MTO） conversion is still a subject of debate. Employing periodic density functional theory calculations, the olefin-based cycle was studied using tetramethylethene（TME） as a representative olefinic hydrocarbon pool in H-SAPO-18 zeotype. The overall free energy barrier at 673 K was calculated and found to be less than 150 kJ/mol in the TME-based cycle, much lower than those in the aromatic-based cycle（〉 200 kJ/mol）, indicating that olefins themselves are the dominant active hydrocarbon pool species in H-SAPO-18. The similarity of the intermediates involved between the aromatic-based cycle and the olefin-based cycle was also highlighted, revealing that both cycles were pattern-consistent. The selectivity related to the distribution of cracking precursors, such as higher olefins or carbenium ions, as a result of the olefin-based cycle for the MTO conversion. The enthalpy barrier of the crack-ing step scaled linearly with the number of carbon atoms of cracking precursors to produce ethene or propene with ethene being much less favored than propene for cracking of C7 and higher pre-cursors. This work highlighted the importance of the olefin-based cycle in H-SAPO-18 for the MTO conversion and established the similarity between the olefin-based and aromatic-based cycles.展开更多
A series of ZSM-5@MCM-41 core-shell composite materials prepared via a multi-cycle-sol-gel coating strategy is investigated as the catalyst for benzene alkylation with ethylene,in which both ethylbenzene and para-diet...A series of ZSM-5@MCM-41 core-shell composite materials prepared via a multi-cycle-sol-gel coating strategy is investigated as the catalyst for benzene alkylation with ethylene,in which both ethylbenzene and para-diethylbenzene(p-DEB)are aimed as the target products.With multi-cycle-sol-gel coating,the external acid sites on the samples are gradually passivated by the inert MCM-41 shell.As a result,the shape selectivity to p-DEB is greatly enhanced.Nevertheless,the coating of mesoporous MCM-41 shell on ZSM-5 accelerates deactivation of the catalyst only due to the dilution effect of ZSM-5 content in the catalyst at the same space velocity,which is a reason that core-shell ZSM-5@MCM-41 will potentially be a practical catalyst in shape selective alkylation of benzene.In order to enhance the yield of p-DEB on ZSM-5@MCM-41,the reaction conditions at the fixed bed reactor including temperature,the molar rate of benzene to ethylene and GHSV,are also optimized.展开更多
A ZSM-5/MOR co-crystalline zeolite was synthesized without using the template. The physico-chemical properties of the zeolite were characterized by XRD, FT-IR, SEM and TPD and then compared with the co-crystalline zeo...A ZSM-5/MOR co-crystalline zeolite was synthesized without using the template. The physico-chemical properties of the zeolite were characterized by XRD, FT-IR, SEM and TPD and then compared with the co-crystalline zeolite synthesized with a template. Analytical results indicated that they were similar in structure and composition. The influences ofpH value and Si/Al ratio on synthesis were studied. It was found that a high pH value or a low Si/AI ratio could provide better environment for mordenite （MOR） crystallization. The zeolites applied as catalysts in naphtha catalytic cracking for producing ethylene and propylene showed outstanding catalytic performance with the total yield of ethylene and propylene reaching 55 m%. The process could achieve most favorable efficiency when the catalyst contained 5 m% of MOR.展开更多
Different tougheners including methyl methacrylate-butadiene-styrene terpolymer (MBS, core-shell type), maleic anhydride (MAH) grafted ethylene-octene copolymer (EOM), and MAH grafted polyethylene wax (PEM) were inves...Different tougheners including methyl methacrylate-butadiene-styrene terpolymer (MBS, core-shell type), maleic anhydride (MAH) grafted ethylene-octene copolymer (EOM), and MAH grafted polyethylene wax (PEM) were investigated for toughening the polycarbonate (PC) composites reinforced by short carbon fiber (SCF) and flake graphene (FG). The effects of tougheners on the preparation, thermal conductivity and mechanical properties of PC composites were studied. Scanning electron microscopy was used for characterizing the impact fracture surfaces of the composites. The results showed that introducing tougheners into the carbon reinforced PC composites was beneficial to improving the processability, and PEM was more effective than EOM and MBS. Meanwhile, the through-thickness and the in-plan thermal conductivity decreased to some degree due to the isolated island effects of tougheners. Moreover, the brittle PC composites with high flexural stress could be easily toughened by tougheners. In contrast, PEM had better toughening function than EOM and MBS, and correspondingly, the stiffness of the composites was the lowest for the PEM toughened systems. The fractography revealed that dense and uniformly distributed carbon fillers dispersed in matrix PC and circular cavities coexisted in the composites. The naked fiber length gradually increased as the ductility of composite materials improved.展开更多
In this work, graphene oxide(GO) nanosheets with surface modification by Tannic and Fe coordination complexes(TA-Fe) were incorporated into poly(vinylidene fluoride)(PVDF) to prepare high constant but low loss polymer...In this work, graphene oxide(GO) nanosheets with surface modification by Tannic and Fe coordination complexes(TA-Fe) were incorporated into poly(vinylidene fluoride)(PVDF) to prepare high constant but low loss polymer nanocomposites, and the effect of TA-Fe interlayer on dielectric properties of the GO@TA-Fe/PVDF nanocomposites was investigated. The results indicate that the dosage, mixing ratio, and reaction time of TA-Fe complexes have obvious influences on the dielectric properties of the nanocomposites. Furthermore, the TA-Fe interlayer significantly influences the electrical properties of GO@TA-Fe nanoparticles and their PVDF composites, and the GO@TA-Fe/PVDF composites exhibit superior dielectric properties compared with raw GO/PVDF. Dielectric losses of the GO@TA-Fe/PVDF are significantly suppressed to a rather low level owing to the presence of TA-Fe layer, which serves as an interlayer between the GO sheets, thus preventing them from direct contacting with each other. Additionally, the dynamic dielectric relaxation of the GO/PVDF and GO@TA-Fe/PVDF nanocomposites was investigated in terms of temperature.展开更多
It is difficult to separate the methanol and hydrocarbons in the propylene oxide(PO)purification process due to their forming azeotrope.As for this,a novel PO separation process,in that the deionized water is employed...It is difficult to separate the methanol and hydrocarbons in the propylene oxide(PO)purification process due to their forming azeotrope.As for this,a novel PO separation process,in that the deionized water is employed as extractant and 1,2-propylene glycol(MPG)that is formed from the PO hydrolysis reaction is recovered,is presented in this work.The salient feature of this process is that both the non-catalyzed reactions of PO hydrolysis to form MPG and dipropylene glycol(DPG)are simultaneously considered and MPG by-product with high purity is obtained in virtue of the deionized water as reflux liquid and side take-off in MPG column.In addition,the ionic liquid(IL)extractant is screened through the conductorlike screening model for segment activity coefficient(COSMO-SAC)and the comparisons of separation efficiency between the IL and normal octane(nC_(8))extractant for the separation of PO and 2-methylpentane are made.With the non-random two-liquid(NRTL)thermodynamic model,the simulation and optimization design for the full flow sheet are performed and the effects of the key operation parameters such as solvent ratio,theoretical stages,feeding stage etc.on separation efficiency are detailedly discussed.The results show that the mass purity and the mass yield of PO can be up to 99.99%and 99.0%,and the condenser duty,reboiler duty and PO loss in the process with IL extractant can be decreased by 69.66%,30.21%and 78.86%compared to ones with nC_(8).The total annual cost(TAC)calculation also suggests that the TAC would be significantly reduced if using IL in replace of nC_(8) for the investigated process.The presented results would provide a useful guide for improving the quality of PO product and the economic efficiency of industrial plant.展开更多
Using cetyl-trimethyl-ammonium bromide （CTMAB） as template and tetraethylortho-silicate （TEOS） as silica source, the MCM-41 mesoporous materials incorporated in framework by Y, Nd and Sm were synthesized by hydrot...Using cetyl-trimethyl-ammonium bromide （CTMAB） as template and tetraethylortho-silicate （TEOS） as silica source, the MCM-41 mesoporous materials incorporated in framework by Y, Nd and Sm were synthesized by hydrothermal synthesis method. The structure, morphology of materials and the state of Y, Nd, Sm in materials were investigated by means of XRD, nitrogen adsorption-desorption, SEM, IR spectrometry, TG-DTA. The XRD results indicate that the samples possess the mesoporous MCM-41 structures with ordered hexagonal arrangements. Y, Nd and Sm ions can get into the framework of mesoporous materials. Nitrogen adsorption desorption isotherms show that the samples have typical mesopores characteristics. SEM micrographs reveal that incorporated sampies show a spherical morphology and the diameters are averagely 0. l0 to 0.15 μm. In IR spectrum of samples, there are the feature adsorption peaks about Si-O-Ln（Ln=Y, Sm, Nd）at 960-985 cm^-1, which affirm that Y, Nd, Sm ions locate in the framework of several mesoporous materials. Results from TG-DTA analysis suggest that two different template sorption sites exist in the framework of YMCM-41, SmMCM-41, NdMCM-41, which powerfully proves that the presence of Y, Nd and Sm in Si framework of the materials.展开更多
The sustainable development of the chemical industry requires novel and efficient catalysts and catalytic processes,especially eco-friendly and intrinsically safe processes.The idea is to improve the selectivity,activ...The sustainable development of the chemical industry requires novel and efficient catalysts and catalytic processes,especially eco-friendly and intrinsically safe processes.The idea is to improve the selectivity,activity,and stability of the catalyst in an appropriate reactor.Therefore,it is of great academic and industrial significance to conduct in-situ characterization of a working catalyst while testing its catalytic performance.This is beneficial for a comprehensive study on the dynamic evolution of the catalyst structure under real conditions,deepening the understanding of the structure-performance relationship of catalysts,and providing a scientific basis for the development of future generation catalytic technology.Thus far,it is still a great challenge to realize full life cycle characterization of heterogeneous catalysts from catalyst formation and function to deactivation under real world conditions.In this mini review,we summarize the characterization strategies for heterogeneous catalysts,using zeolite,metal,and metal oxide catalysts as typical examples.The research strategies for the approximation of industrial conditions,multi-scale in-situ characterization devices,and computational modeling of realistic conditions should provide insight for the research and development of industrial catalysis.展开更多
文摘Direct conversion of syngas to light olefins(STO)on bifunctional catalysts has garnered significant attention,yet a comprehensive understanding of the reaction pathway and reaction kinetics remains elusive.Herein,we theoretically addressed the kinetics of the direct STO reaction on typical ZnAl_(2)O_(4)/zeolite catalysts by establishing a complete reaction network,consisting of methanol synthesis and conversion,water gas shift(WGS)reaction,olefin hydrogenation,and other relevant steps.The WGS reaction occurs very readily on ZnAl_(2)O_(4) surface whereas which is less active towards alkane formation via olefin hydrogenation,and the latter can be attributed to the characteristics of the H_(2) heterolytic activation and the weak polarity of olefins.The driving effect of zeolite component towards CO conversion was demonstrated by microkinetic simulations,which is sensitive to reaction conditions like space velocity and reaction temperature.Under a fixed ratio of active sites between oxide and zeolite components,the concept of the“impossible trinity”of high CO conversion,high olefin selectivity,and high space velocity can thus be manifested.This work thus provides a comprehensive kinetic picture on the direct STO conversion,offering valuable insights for the design of each component of bifunctional catalysts and the optimization of reaction conditions.
基金funding support received from China Petrochemical Corporation(Sinopec Group).
文摘The purpose of this study is to develop novel P-Mo-V heteropoly compound catalysts for the oxidation of methacrolein to methacrylic acid.The introduction of Cu,as a modifying element,was employed to enhance the catalytic performance.Experimental results show that the addition of Cu significantly improved the catalyst performance,increasing the conversion rate of methacrolein from 17.2%to 84.2%,while the yield of methacrylic acid was boosted from 5.5%to 51.7%.A series of characterization results showed that both P-Mo-V and Cu-P-Mo-V catalysts primarily exhibited the crystal phase of[PMo_(12)O_(40)]^(3−),with a small amount of[PMo_(11)VO_(40)]^(3−)phase.However,the Cu-P-Mo-V catalyst exhibited much better oxidation–reduction ability compared to the P-Mo-V catalyst.Isolated Cu atoms were found to exist in a highly decentralized tetrahedral coordination structure,bridged by oxygen atoms within the heteropoly compound framework.The addition of Cu resulted in notable alterations in the modulation of the surface electronic structure,enhancement of oxidation–reduction ability,and optimization of the reaction pathway,thereby improving the overall catalytic activity of the catalyst.This study not only provides new insights into the modification of P-Mo-V heteropoly compound catalysts but also lays a foundation for understanding their catalytic mechanisms in organic synthesis reactions,demonstrating the potential of modifying elements in improving catalyst performance.
文摘The distributions of framework aluminum(Al)in zeolites critically govern the location and speciation of active copper(Cu)centers,thereby influencing their performance in ammonia selective catalytic reduction(NH_(3)-SCR)of nitrogen oxides(NO_(x)).Conventional Cu-SSZ-39(Cu-SSZ-39-T)exhibits excellent hydrothermal stability but limited low-temperature activity(150–225℃)due to a low concentration of Al in 8-membered rings(8MRs)that inhibits the formation of active[Cu(OH)]^(+)-Z species.Herein,an SSZ-39 zeolite synthesized with potassium ions(SSZ-39-K)achieved a significantly higher 8MR Al fraction(37.6%).Density functional theory calculations and H_(2)-temperature-programmed reduction analyses confirmed that the increased 8MR Al population facilitated the formation of[Cu(OH)]^(+)-Z species.Aged Cu-SSZ-39-K exhibited nearly twice the NO_(x)conversion of aged Cu-SSZ-39-T in the 150–225℃range while maintaining comparable high-temperature activity(250–550℃)under a gas hourly space velocity of 250,000 h^(-1).Enhanced low-temperature performance is particularly beneficial for mitigating NO_(x)emissions during cold-start phase.Moreover,SSZ-39-K was synthesized with a high crystallization yield(~65%),nearly double the highest yield(33%)reported for direct synthesis routes.This work establishes a robust strategy for tailoring Al distributions in SSZ-39 zeolites,offering an effective pathway to improve low-temperature NH_(3)-SCR performance and promote practical implementation.
文摘A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the structure-directing agent for the MWW layered structure;and dicyclohexylamine(DCHA),in the role of an in-situ delaminating agent.By varying the amount of DCHA,partially and fully delaminated MWW zeolites having two MWW structure layers and one single layer,respectively,were obtained.These were denoted as SCM-1(Sinopec Composite Material)and SCM-6,respectively.The delaminated materials possess ultra-large external surface areas,and the transmission electron microscopy images illustrated their layered nature.In the reaction of liquid phase benzene alkylation with ethylene,SCM-1,the double-layered MWW zeolite,exhibited far superior catalytic performance compared to zeolite MCM-22.
基金Supports by the National Key Research and Development Plan(2016YFB0301503)the Jiangsu Natural Science Foundation for Distinguished Young Scholars(BK20150044)+3 种基金the National Natural Science Foundation of China(91534110,21606124)the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province(14KJB530004)the Foundation from State Key Laboratory of Materials-Oriented Chemical Engineering(ZK201402,ZK201407)the Technology Innovation Foundation for Science and Technology Enterprises in Jiangsu Province(BC2015008)
文摘The alkylation of benzene with isopropanol over beta-zeolite is a more cost-effective solution to cumene production. During the benzene alkylation cycles, the cumene selectivity slowly increased, while the benzene conversion presented the sharp decrease due to catalyst deactivation. The deactivation mechanism of betazeolite catalyst was investigated by characterizing the fresh and used catalysts. The XRD, SEM and TEM results show that the crystalline and particle size of the beta-zeolite catalyst almost remained stable during the alkylation cycles. The drop in catalytic activity and benzene conversion could be explained by the TG, BET,NH_3-TPD and GC–MS results. The organic matters mainly consisted of ethylbenzene, p-xylene and 1-ethyl-3-(1-methyl) benzene produced in the benzene alkylation deposited in the catalyst, which strongly reduced the specific surface area of beta-zeolite catalyst. Moreover, during the reaction cycles, the amount of acidity also significantly decreased. As a result, the catalyst deactivation occurred. To maintain the catalytic performance,the catalyst regeneration was carried out by using ethanol rinse and calcination. The deactivated catalyst could be effectively regenerated by the calcination method and the good catalytic performance was obtained.
基金Supported by the National Natural Science Foundation of China （Nos.20236010,20476004） and China Petroleum ＆ Chemical Corporation （No.X504023）.
文摘Four ZSM-5 zeolite catalysts with different Si/Al ratios for the catalytic cracking of C4 fractions to produce ethylene and propylene were prepared in this study.First,the adsorption isotherms of pure n-butane and butene-1 and their mixtures on these catalysts at 300K and p=0—100kPa were measured using the intelligent gra- vimetric analyzer.The experimental results indicate that the presence of Al can significantly affect the adsorption of butene-1 than that of n-butane on ZSM-5 zeolites.Then,the double Langmuir(DL)model was applied to study the pure gas adsorption on ZSM-5 zeolites for pure n-butane and butene-1.By combining the DL model with the ideal adsorbed solution theory(IAST),the IAST-DL model was applied to model the butene-1(1)/n-butane(2)binary mixture adsorption on ZSM-5 zeolites with different Si/Al ratios.The calculated results are in good agreement with the experimental data,indicating that the IAST-DL model is effective for the present systems.Finally,the adsorp- tion over a wide range of variables was predicted at low pressure and 300K by the model proposed.It is found that the selectivity of butene-1 over n-butane increases linearly with the decrease of Si/Al ratio.A correlation between the selectivity and Si/Al ratio of the sample was proposed at 300K and p=0.08MPa.
基金supported by the National Basic Research Program of China (2009CB623504)the National Science Foundation of China (21103231)Shanghai Science Foundation (11ZR1449700)
文摘Selectivity control is a difficult scientific and industrial challenge in methanol-to-olefins(MTO)conversion.It has been experimentally established that the topology of zeolite catalysts influenced the distribution of products.Besides the topology effect on reaction kinetics,the topology influences the diffusion of reactants and products in catalysts as well.In this work,by using COMPASS force-field molecular dynamics method,we investigated the intracrystalline diffusion of ethene and propene in four different zeolites,CHA,MFI,BEA and FAU,at different temperatures.The self-diffusion coefficients and diffusion activation barriers were calculated.A strong restriction on the diffusion of propene in CHA was observed because the self-diffusion coefficient ratio of ethene to propene is larger than 18 and the diffusion activation barrier of propene is more than 20 kJ/mol in CHA.This ratio decreases with the increase of temperature in the four investigated zeolites.The shape selectivity on products from diffusion perspective can provide some implications on the understanding of the selectivity difference between HSAPO-34 and HZSM-5 catalysts for the MTO conversion.
基金This work was supported by the National Key Research and Development Program(2016YFB0901505)the Natural Science Foundation of China(22005190,21938005)+1 种基金the Science&Technology Commission of Shanghai Municipality(19DZ1205500)Zhejiang Key Research and Development Program(2020C01128).
文摘NASICON-type Na_(3)V_(2)(PO_(4))_(3) is a promising electrode material for developing advanced sodium-ion batteries.Preparing Na_(3)V_(2)(PO_(4))_(3) with good performance by a cost-effective and large-scale method is significant for industrial applications.In this work,a porous Na_(3)V_(2)(PO_(4))_(3)/C cathode material with excellent electrochemical performance is successfully prepared by an agar-gel combined with freeze-drying method.The Na_(3)V_(2)(PO_(4))_(3)/C cathode displayed specific capacities of 113.4 mAh·g^(-1),107.0 mAh·g^(-1) and 87.1 mAh·g^(-1) at 0.1 C,1 C and 10 C,respectively.For the first time,the 500-mAh soft-packed symmetrical sodium-ion batteries based on Na_(3)V_(2)(PO_(4))_(3)/C electrodes are successfully fabricated.The 500-mAh symmetrical batteries exhibit outstanding low temperature performance with a capacity retention of 83%at 0℃ owing to the rapid sodium ion migration ability and structural stability of Na_(3)V_(2)(PO_(4))_(3)/C.Moreover,the thermal runaway features are revealed by accelerating rate calorimetry(ARC)test for the first time.Thermal stability and safety of the symmetrical batteries are demonstrated to be better than lithium-ion batteries and some reported sodium-ion batteries.Our work makes it clear that the soft-packed symmetrical sodium ion batteries based on Na_(3)V_(2)(PO_(4))_(3)/C have a prospect of practical application in high safety requirement fields.
基金This work is financially supported by the National Natural Science Foundation of China (No. 50471045)Shanghai Nano-technology Promotion Center (No. 0452nm026).
文摘The microstructure, electrical properties, and density of Dy2O3-doped ZnO-based varistor ceramics, prepared using high-energy ball milling （HEBM） and sintered at 800℃, were investigated by increasing the cooling rate in the order of H （slow cooling in furnace） → L （cooling in furnace） → K （cooling in air）. With the increase in cooling rate, the grain size and density decreased, the breakdown voltage （VImA/mm） increased, and the nonlinear coefficient （α） and leakage current （IL） exhibited extremum. The sample with the cooling type L showed the best properties with the breakdown voltage of 2650 V/ram, o：of 20.3, IL of 5.2 laA, and density of 5.42 g/cm^3. The barrier height （ФB）, donor concentration （Nd）, density of the interface states （Nd）, and barrier width （ω） all exhibited extremum during the alteration in cooling rate. The different relative amount of Bi-rich phase and its distribution as well as the characteristic parameters of grain boundary, resulting from the alteration of cooling rate, led to the changes in the properties of varistor ceramics.
基金supported by the National Natural Science Foundation of China (20776089)the New Century Excellent Talent Project of China(NCET-05-0783)
文摘In this work, a series of Ni-Mo-Mg-O catalysts with mesoporous structure prepared by sol-gel method were investigated for the oxidative dehydrogenation of propane （ODHP）. The techniques of temperature-programmed reduction with H2 （H2-TPR）, N2 adsorption-desolption, Fourier transform infrared spectroscopy （FT-IR）, X-ray diffraction （XRD） and X-ray photoelectron spectra （XPS） were employed for catalyst characterization. It is found that the activity of the catalysts for ODHP increases first and then decreases with the increase of Mo content. The catalyst with a Mo/Ni atomic ratio of 1/1 exhibits the best catalytic activity, which gives the propene selectivity of 81.4% at a propane conversion of 11.3% under 600 ~C and maintains the good catalytic performance for 22 h on stream. This is related not only to its high reducibility and dispersion as revealed by TPR and XRD, but also to the formation of more selective oxygen species on the MoOz-NiO interface as identified by XPS.
基金supported by National Key Basic Research Program of China (2013CB934101, 2009CB623500)the National Natural Science Foundation of China (21433002, 21573046)the National Key Research and Development Program of China (2016YFB0701100)~~
文摘Catalysis is one of the most cross-cutting technologies in the chemical industry, intensely influenc-ing our daily society. Its practical application is closely related to the engineering disciplines. At present, the academic and industrial research on catalysis in our country has made great break-throughs in fields like hydrocarbon production, oil-quality upgrading processes, green chemical engineering, and other energy and chemical users of catalysis. In this paper, we attempt to summa-rize the industrial catalysis achievements and present a discussion on the direction and the devel-opment strategy for catalysis, based on economic and social demands.
基金financial support from the MOST(No.2017YFA0402800)the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.51888103)。
文摘The effective valuation of catalyst supports in the catalytic oxidation makes the contribution to understand the support effect of great interest.Here,the role of active substrate in the performance and stability of CuFe-Co ternary oxides was studied towards the complete catalytic oxidation of CO.The Cu-Fe-Co oxide thin films were deposited on copper grid mesh(CUGM)using one-step pulsed-spray evaporation chemical vapor deposition method.Crystalline structure and morphology analyses revealed nano-crystallite sizes and do me-top-like morphology.Synergistic effects between Cu,Fe and Co,which affect the surface Cu^2+,Fe^3+,Co^3+and chemisorbed oxygen species(O2 and OH)of thin films over the active support and thus result in better reducibility.The thin film catalysts supported on CUGM exhibited attractive catalytic activity compared to the te rnary oxides supported on ine rt grid mesh at a high gas hourly space velocity.Moreove r,the stability in time-on-stream of the ternary oxides on CUGM was evaluated in the CO oxidation for 30 h.The ad opted deposition strategy ofternary oxides on CUGM presents an excessive amount of adsorbed active oxygen species that play an impo rtant role in the complete CO oxidation.The catalysts supported on CUGM showed better catalytic conve rsion than that on inert grid mesh and some literature-reported noble metal oxides as well as transition metal oxides counterparts,revealing the beneficial effect of the CUGM suppo rt in the improvement of the catalytic performance.
基金supported by the National Key Research and Development Program of China (2016YFB0701100, 2017YFB0702800)the National Natural Science Foundation of China (21673295)~~
文摘The reaction mechanism of zeolite- or zeotype-catalyzed methanol-to-olefins（MTO） conversion is still a subject of debate. Employing periodic density functional theory calculations, the olefin-based cycle was studied using tetramethylethene（TME） as a representative olefinic hydrocarbon pool in H-SAPO-18 zeotype. The overall free energy barrier at 673 K was calculated and found to be less than 150 kJ/mol in the TME-based cycle, much lower than those in the aromatic-based cycle（〉 200 kJ/mol）, indicating that olefins themselves are the dominant active hydrocarbon pool species in H-SAPO-18. The similarity of the intermediates involved between the aromatic-based cycle and the olefin-based cycle was also highlighted, revealing that both cycles were pattern-consistent. The selectivity related to the distribution of cracking precursors, such as higher olefins or carbenium ions, as a result of the olefin-based cycle for the MTO conversion. The enthalpy barrier of the crack-ing step scaled linearly with the number of carbon atoms of cracking precursors to produce ethene or propene with ethene being much less favored than propene for cracking of C7 and higher pre-cursors. This work highlighted the importance of the olefin-based cycle in H-SAPO-18 for the MTO conversion and established the similarity between the olefin-based and aromatic-based cycles.
基金financial support by the National Natural Science Foundation of China(91534115)the National Key Research and Development Project(2016YFC1102300)。
文摘A series of ZSM-5@MCM-41 core-shell composite materials prepared via a multi-cycle-sol-gel coating strategy is investigated as the catalyst for benzene alkylation with ethylene,in which both ethylbenzene and para-diethylbenzene(p-DEB)are aimed as the target products.With multi-cycle-sol-gel coating,the external acid sites on the samples are gradually passivated by the inert MCM-41 shell.As a result,the shape selectivity to p-DEB is greatly enhanced.Nevertheless,the coating of mesoporous MCM-41 shell on ZSM-5 accelerates deactivation of the catalyst only due to the dilution effect of ZSM-5 content in the catalyst at the same space velocity,which is a reason that core-shell ZSM-5@MCM-41 will potentially be a practical catalyst in shape selective alkylation of benzene.In order to enhance the yield of p-DEB on ZSM-5@MCM-41,the reaction conditions at the fixed bed reactor including temperature,the molar rate of benzene to ethylene and GHSV,are also optimized.
基金funded by the National Basic Research Program of China (Project No. 2003CB615804) the joint funding of the National Natural Science Foundation of China and SINOPEC (NO.20736011)
文摘A ZSM-5/MOR co-crystalline zeolite was synthesized without using the template. The physico-chemical properties of the zeolite were characterized by XRD, FT-IR, SEM and TPD and then compared with the co-crystalline zeolite synthesized with a template. Analytical results indicated that they were similar in structure and composition. The influences ofpH value and Si/Al ratio on synthesis were studied. It was found that a high pH value or a low Si/AI ratio could provide better environment for mordenite （MOR） crystallization. The zeolites applied as catalysts in naphtha catalytic cracking for producing ethylene and propylene showed outstanding catalytic performance with the total yield of ethylene and propylene reaching 55 m%. The process could achieve most favorable efficiency when the catalyst contained 5 m% of MOR.
文摘Different tougheners including methyl methacrylate-butadiene-styrene terpolymer (MBS, core-shell type), maleic anhydride (MAH) grafted ethylene-octene copolymer (EOM), and MAH grafted polyethylene wax (PEM) were investigated for toughening the polycarbonate (PC) composites reinforced by short carbon fiber (SCF) and flake graphene (FG). The effects of tougheners on the preparation, thermal conductivity and mechanical properties of PC composites were studied. Scanning electron microscopy was used for characterizing the impact fracture surfaces of the composites. The results showed that introducing tougheners into the carbon reinforced PC composites was beneficial to improving the processability, and PEM was more effective than EOM and MBS. Meanwhile, the through-thickness and the in-plan thermal conductivity decreased to some degree due to the isolated island effects of tougheners. Moreover, the brittle PC composites with high flexural stress could be easily toughened by tougheners. In contrast, PEM had better toughening function than EOM and MBS, and correspondingly, the stiffness of the composites was the lowest for the PEM toughened systems. The fractography revealed that dense and uniformly distributed carbon fillers dispersed in matrix PC and circular cavities coexisted in the composites. The naked fiber length gradually increased as the ductility of composite materials improved.
基金financially supported by the National Natural Science Foundation of China(Nos.51577154,21373158 and21073139)the Key Laboratory of Engineering Dielectrics and Its Application,Ministry of Education,Harbin University of Science and Technology(No.KF20151111)+1 种基金the Natural Science Foundation of Shaanxi Province,China(No.2016JM5014)the fellowship provided by the China Scholarship Council(CSC)
文摘In this work, graphene oxide(GO) nanosheets with surface modification by Tannic and Fe coordination complexes(TA-Fe) were incorporated into poly(vinylidene fluoride)(PVDF) to prepare high constant but low loss polymer nanocomposites, and the effect of TA-Fe interlayer on dielectric properties of the GO@TA-Fe/PVDF nanocomposites was investigated. The results indicate that the dosage, mixing ratio, and reaction time of TA-Fe complexes have obvious influences on the dielectric properties of the nanocomposites. Furthermore, the TA-Fe interlayer significantly influences the electrical properties of GO@TA-Fe nanoparticles and their PVDF composites, and the GO@TA-Fe/PVDF composites exhibit superior dielectric properties compared with raw GO/PVDF. Dielectric losses of the GO@TA-Fe/PVDF are significantly suppressed to a rather low level owing to the presence of TA-Fe layer, which serves as an interlayer between the GO sheets, thus preventing them from direct contacting with each other. Additionally, the dynamic dielectric relaxation of the GO/PVDF and GO@TA-Fe/PVDF nanocomposites was investigated in terms of temperature.
基金provided by the National Key Research and Devolopment Program of China(2017YFB0702800)the National Natural Science Foundation of China (21878025, 22078026)。
文摘It is difficult to separate the methanol and hydrocarbons in the propylene oxide(PO)purification process due to their forming azeotrope.As for this,a novel PO separation process,in that the deionized water is employed as extractant and 1,2-propylene glycol(MPG)that is formed from the PO hydrolysis reaction is recovered,is presented in this work.The salient feature of this process is that both the non-catalyzed reactions of PO hydrolysis to form MPG and dipropylene glycol(DPG)are simultaneously considered and MPG by-product with high purity is obtained in virtue of the deionized water as reflux liquid and side take-off in MPG column.In addition,the ionic liquid(IL)extractant is screened through the conductorlike screening model for segment activity coefficient(COSMO-SAC)and the comparisons of separation efficiency between the IL and normal octane(nC_(8))extractant for the separation of PO and 2-methylpentane are made.With the non-random two-liquid(NRTL)thermodynamic model,the simulation and optimization design for the full flow sheet are performed and the effects of the key operation parameters such as solvent ratio,theoretical stages,feeding stage etc.on separation efficiency are detailedly discussed.The results show that the mass purity and the mass yield of PO can be up to 99.99%and 99.0%,and the condenser duty,reboiler duty and PO loss in the process with IL extractant can be decreased by 69.66%,30.21%and 78.86%compared to ones with nC_(8).The total annual cost(TAC)calculation also suggests that the TAC would be significantly reduced if using IL in replace of nC_(8) for the investigated process.The presented results would provide a useful guide for improving the quality of PO product and the economic efficiency of industrial plant.
文摘Using cetyl-trimethyl-ammonium bromide （CTMAB） as template and tetraethylortho-silicate （TEOS） as silica source, the MCM-41 mesoporous materials incorporated in framework by Y, Nd and Sm were synthesized by hydrothermal synthesis method. The structure, morphology of materials and the state of Y, Nd, Sm in materials were investigated by means of XRD, nitrogen adsorption-desorption, SEM, IR spectrometry, TG-DTA. The XRD results indicate that the samples possess the mesoporous MCM-41 structures with ordered hexagonal arrangements. Y, Nd and Sm ions can get into the framework of mesoporous materials. Nitrogen adsorption desorption isotherms show that the samples have typical mesopores characteristics. SEM micrographs reveal that incorporated sampies show a spherical morphology and the diameters are averagely 0. l0 to 0.15 μm. In IR spectrum of samples, there are the feature adsorption peaks about Si-O-Ln（Ln=Y, Sm, Nd）at 960-985 cm^-1, which affirm that Y, Nd, Sm ions locate in the framework of several mesoporous materials. Results from TG-DTA analysis suggest that two different template sorption sites exist in the framework of YMCM-41, SmMCM-41, NdMCM-41, which powerfully proves that the presence of Y, Nd and Sm in Si framework of the materials.
文摘The sustainable development of the chemical industry requires novel and efficient catalysts and catalytic processes,especially eco-friendly and intrinsically safe processes.The idea is to improve the selectivity,activity,and stability of the catalyst in an appropriate reactor.Therefore,it is of great academic and industrial significance to conduct in-situ characterization of a working catalyst while testing its catalytic performance.This is beneficial for a comprehensive study on the dynamic evolution of the catalyst structure under real conditions,deepening the understanding of the structure-performance relationship of catalysts,and providing a scientific basis for the development of future generation catalytic technology.Thus far,it is still a great challenge to realize full life cycle characterization of heterogeneous catalysts from catalyst formation and function to deactivation under real world conditions.In this mini review,we summarize the characterization strategies for heterogeneous catalysts,using zeolite,metal,and metal oxide catalysts as typical examples.The research strategies for the approximation of industrial conditions,multi-scale in-situ characterization devices,and computational modeling of realistic conditions should provide insight for the research and development of industrial catalysis.
