CO_(2)hydrogenation is an attractive way to store and utilize carbon dioxide generated by industrial processes,as well as to produce valuable chemicals from renewable and abundant resources.Iron catalysts are commonly...CO_(2)hydrogenation is an attractive way to store and utilize carbon dioxide generated by industrial processes,as well as to produce valuable chemicals from renewable and abundant resources.Iron catalysts are commonly used for the hydrogenation of carbon oxides to hydrocarbons.Iron-molybdenum catalysts have found numerous applications in catalysis,but have been never evaluated in the CO_(2)hydrogenation.In this work,the structural properties of iron-molybdenum catalysts without and with a promoting alkali metal(Li,Na,K,Rb,or Cs)were characterized using X-ray diffraction,hydrogen temperatureprogrammed reduction,CO_(2)temperature-programmed desorption,in-situ^(57)Fe Mossbauer spectroscopy and operando X-ray adsorption spectroscopy.Their catalytic performance was evaluated in the CO_(2)hydrogenation.During the reaction conditions,the catalysts undergo the formation of an iron(Ⅱ)molybdate structure,accompanied by a partial reduction of molybdenum and carbidization of iron.The rate of CO_(2)conversion and product selectivity strongly depend on the promoting alkali metals,and electronegativity was identified as an important factor affecting the catalytic performance.Higher CO_(2)conversion rates were observed with the promoters having higher electronegativity,while low electronegativity of alkali metals favors higher light olefin selectivity.展开更多
The ever-growing pursuit of high energy density batteries has triggered extensive efforts toward developing alkali metal(Li,Na,and K)battery(AMB)technologies owing to high theoretical capacities and low redox potentia...The ever-growing pursuit of high energy density batteries has triggered extensive efforts toward developing alkali metal(Li,Na,and K)battery(AMB)technologies owing to high theoretical capacities and low redox potentials of metallic anodes.Typically,for new battery systems,the electrolyte design is critical for realizing the battery electrochemistry of AMBs.Conventional electrolytes in alkali ion batteries are generally unsuitable for sustaining the stability owing to the hyper-reactivity and dendritic growth of alkali metals.In this review,we begin with the fundamentals of AMB electrolytes.Recent advancements in concentrated and fluorinated electrolytes,as well as functional electrolyte additives for boosting the stability of Li metal batteries,are summarized and discussed with a special focus on structure-composition-performance relationships.We then delve into the electrolyte formulations for Na-and K metal batteries,including those in which Na/K do not adhere to the Li-inherited paradigms.Finally,the challenges and the future research needs in advanced electrolytes for AMB are highlighted.This comprehensive review sheds light on the principles for the rational design of promising electrolytes and offers new inspirations for developing stable AMBs with high performance.展开更多
Alkali metal-carbon dioxide(Li/Na/K-CO_(2))batteries are emerging electrochemical energy storage technologies in the context of the energy crisis and the urgent demand for carbon neutrality.Alkali metal-CO_(2) batteri...Alkali metal-carbon dioxide(Li/Na/K-CO_(2))batteries are emerging electrochemical energy storage technologies in the context of the energy crisis and the urgent demand for carbon neutrality.Alkali metal-CO_(2) batteries offer a new strategy for CO_(2) fixation and utilization,and thus has been receiving considerable attention in recent years.Considerable progress has been achieved since alkali metal-CO_(2) batteries were invented,especially in terms of development of new electrode materials,and yet,research is lacking on the underlying mechanisms of the systems.This is the first typical review focusing on the electrochemical mechanisms of metal-CO_(2) batteries that summarizes the current understanding of and provides insights into the thermodynamic reaction pathways,the kinetic characteristics,and the crucial factors determining the reaction mechanisms in alkali metal-CO_(2) batteries.The review starts with the fundamental concepts of alkali metal-CO_(2) batteries,followed by a comprehensive discussion of the working mechanisms on cathodes and anodes.Moreover,the operation mechanisms of state-of-the-art electrolytes,including liquid and(quasi-)solid-state electrolytes,are also described.Finally,we identify the unsolved problems in current alkali metal-CO_(2) batteries and propose potential topics for future research.展开更多
Rechargeable alkali metal-air batteries are considered as the most promising candidate for the power source of electric vehicles(EVs) due to their high energy density. However, the practical application of metal-air b...Rechargeable alkali metal-air batteries are considered as the most promising candidate for the power source of electric vehicles(EVs) due to their high energy density. However, the practical application of metal-air batteries is still challenging. In the past decade, many strategies have been purposed and explored, which promoted the development of metal-air batteries. The reaction mechanisms have been gradually clarified and catalysts have been rationally designed for air cathodes. In this review, we summarize the recent development of alkali metal-air batteries from four parts: metal anodes, electrolytes, air cathodes and reactant gases, wherein we highlight the important achievement in this filed. Finally problems and prospective are discussed towards the future development of alkali metal-air batteries.展开更多
The kinetics of coke solution loss reaction with and without sodium carbonate were investigated under the reaction atmosphere of carb on dioxide. The variables of gas flow rate and coke particle size were explored to ...The kinetics of coke solution loss reaction with and without sodium carbonate were investigated under the reaction atmosphere of carb on dioxide. The variables of gas flow rate and coke particle size were explored to eliminate the external and inteirial diffusion, respectively. Then, the improved method combining with the least square and the genetic algorithm was proposed to solve the homogeneous model and the shrinking core model. It was found that the improved genetic algorithm method has good stability by studying the fitness function at each generation. In the homogeneous model, the activation energy with and without sodium carbonate was 54.89 and 95.56 kJ/mol, respectively. And. the activation energy with and without sodium carbonate in the shrinking core model was 49.83 and 92.18 kJ/mol, respectively. Therefore, it was concluded that the sodium carbonate has the catalytic action. In addition, results showed that the estimated conversions were agreed well with the experimental ones, which indicated that the calculated kinetic parameters were valid and the proposed method was successfully developed.展开更多
This work evaluated the effects of inherent alkali and alkaline earth metals on nitrogen transformation during steam gasification of Shengli lignite at the temperature of 873-1173 K in a fluidized-bed/fixed-bed quartz...This work evaluated the effects of inherent alkali and alkaline earth metals on nitrogen transformation during steam gasification of Shengli lignite at the temperature of 873-1173 K in a fluidized-bed/fixed-bed quartz reactor. The results indicated that the alkali metal Na and alkaline earth metals Ca, Mg in coal have different effects on inherent nitrogen transformation to NH3, HCN and char-N during the lignite steam gasification. Specifically during the steam gasification of Shengli lignite, Na and Ca, Mg not only catalyze the inherent nitrogen conversions to NH3, but also promote the secondary reactions of the nascent char-N as well as the generation of NH3 from the generated HCN, meanwhile they also inhibited the inherent nitrogen conversion to HCN and char-N. The presence of Na, Ca and Mg hindered the formation of oxidized nitrogen (N-X) functional groups, but enhanced pyridinic nitrogen (N-6) and quaternary nitrogen's (N-Q) formation in char.展开更多
EAB zeolite was successfully prepared and applied to selective adsorption of Li^(+),Na^(+)and K^(+)ions.The physical and chemical properties of the adsorbent were characterized by X-ray diffraction(XRD),X-ray fluoresc...EAB zeolite was successfully prepared and applied to selective adsorption of Li^(+),Na^(+)and K^(+)ions.The physical and chemical properties of the adsorbent were characterized by X-ray diffraction(XRD),X-ray fluorescence(XRF),scanning electron microscope(SEM)and thermogravimetry(TG)methods.The ion exchange behaviours for Li^(+),Na^(+)and K^(+)ions in monomcomponent and multicomponent solutions were studied.In independent ion exchange,the ion exchange capacities ratiosα(/Na/Li)andα(K/Li)were 3.8 and 6.2,respectively.In competitive ion exchange,the selectivitiesβ(Na/Li)andβ(K/Li)increased with the initial concentrations and reached 409 and 992 when the initial concentrations was 100 mmol/L.The thermodynamic study results showed that Gibbs free energy change(ΔGΘ)of ion exchange reaction between Li-EAB and K^(+)was-34.96 kJ/mol,indicating that ion exchange of K^(+)ions was more energetically favourable than Li^(+)ions.The calculation results showed that the energy barriers of ion exchange increased in the order K^(+)Na^(+)<Li^(+).The study shows that EAB zeolite is potential to be used in the separation of alkali ions.展开更多
Alkali metal ion batteries(AMIBs)are playing an irreplaceable part in the energy revolution,due to their intrinsic advantages of large capacity/power density and abundance of alkali metal ions in the earth’s crust.De...Alkali metal ion batteries(AMIBs)are playing an irreplaceable part in the energy revolution,due to their intrinsic advantages of large capacity/power density and abundance of alkali metal ions in the earth’s crust.Despite their great promise,the inborn deficiencies of commercial graphite and other anodes being researched so far call for the quest of better alternatives that exhibit all-round performance with the balance of energy/power density and cycling stability.Gallium-based materials,with impressive capacity utilization and self-healing ability,provide an anticipated solution to this conundrum.In this review,an overview on the recent progress of gallium-based anodes and their storage mechanism is presented.The current strategies used as engineering solutions to meet the scientific challenges ahead are discussed,in addition to the insightful outlook for possible future study.展开更多
The occurrence modes of alkali and alkaline-earth metals(AAEMs) in coal relate to their release behavior and ash formation during combustion. To better understand the transformation of AAEMs,the release behavior of wa...The occurrence modes of alkali and alkaline-earth metals(AAEMs) in coal relate to their release behavior and ash formation during combustion. To better understand the transformation of AAEMs,the release behavior of water-soluble,HCl-soluble,HCl-insoluble AAEMs during Shenmu coal(SM coal) oxy-fuel combustion in the presence of SO2 and H2O in a drop-tube reactor was investigated through serial dissolution using H2O and HCl solutions. The results show that the release rates of AAEMs increase with an increase in temperature under the three atmospheres studied. The high release rates of Mg and Ca from SM coal are dependent on the high content of soluble Mg and Ca in SM coal. SO2 inhibits the release rates of AAEMs,while H2O promotes them. The effects of SO2 and H2O on the Na and K species are more evident than those on Mg and Ca species. All three types of AAEMs in coal can volatilize in the gas phase during coal combustion. The W-type AAEMs release excessively,whereas the release rates of I-type AAEMs are relatively lower. Different types of AAEM may interconvert through different pathways under certain conditions. Both SO2 and H2O promote the transformation reactions. The effect of SO2 was related to sulfate formation and the promotion by H2O occurs because of a decrease in the melting point of the solid as well as the reaction of H2O.展开更多
Metal-organic frameworks(MOFs) have attracted much attention as adsorbents for the separation of CO2 from flue gas or natural gas. Here,a typical metal-organic framework HKUST-1(also named Cu-BTC or MOF-199) was chemi...Metal-organic frameworks(MOFs) have attracted much attention as adsorbents for the separation of CO2 from flue gas or natural gas. Here,a typical metal-organic framework HKUST-1(also named Cu-BTC or MOF-199) was chemically reduced by doping it with alkali metals(Li, Na and K) and they were further used to investigate their CO2 adsorption capacities. The structural information, surface chemistry and thermal behavior of the prepared adsorbent samples were characterized by X-ray powder diffraction(XRD), thermo-gravimetric analysis(TGA)and nitrogen adsorption-desorption isotherm analysis. The results showed that the CO2 storage capacity of HKUST-1 doped with moderate quantities of Li+, Na+and K+, individually, was greater than that of unmodified HKUST-1. The highest CO2 adsorption uptake of 8.64mmol/g was obtained with 1K-HKUST-1, and it was ca. 11% increase in adsorption capacity at 298 K and 18 bar as compared with HKUST-1. Moreover, adsorption tests showed that HKUST-1 and 1K-HKUST-1 displayed much higher adsorption capacities of CO2 than those of N2. Finally, the adsorption/desorption cycle experiment revealed that the adsorption performance of 1K-HKUST-1 was fairly stable, without obvious deterioration in the adsorption capacity of CO2 after 10 cycles.展开更多
With the increasing demand for large-scale battery systems in electric vehicles(EVs) and smart renewable energy grids, organic materials including small molecules and polymers utilized as electrodes in rechargeable ba...With the increasing demand for large-scale battery systems in electric vehicles(EVs) and smart renewable energy grids, organic materials including small molecules and polymers utilized as electrodes in rechargeable batteries have received increasing attraction. In recent years, two-dimensional(2D) organic materials possessing planar layered architecture exhibit optional chemical modification, high specific surface area as well as unique electrical/magnetic properties, which have been emerging as the promising functional materials for wide applications in optoelectronics, catalysis, sensing, etc. Integrating with high-density redox-active sites and hierarchical porous structure, significant achievements in 2D organic materials as cathode materials for alkali-metal-ion batteries have been witnessed. In this review, the recent progress in synthetic approaches, structure analyses, electrochemical characterizations of 2D organic materials as well as their application in alkali-metal-ion batteries containing lithium ion battery(LIB), lithium sulfur battery(LSB), lithium air battery(LAB) and sodium ion battery(SIB) are summarized systematically,and their current challenges including cycling stability and electron conductivity for cathode materials in battery fields are also discussed.展开更多
In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpr...In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpressed as follows: GmE= xAxB[(λ11 +λ 12T) + (λ21 + λ22T)xB] The calculation of the model parameters. λ11 ,λ12, λ21 and λ22, was carried out numerically from the phase diagrams for 11 alkali metal-alkali halide or alkali earth metal-halide systems. In addition, artificial neural network trained by known data has been used to predict the values of these model parameters. The predicted results are in good agreement with the calculated ones. The applicability of the subregular solution model to the alkali metal-alkali halide or alkali earth metal-halide systems were tested by comparing the available experimental composition along the boundary of miscibility gap with the calculated ones which were obtained by using genetic algorithm. The good agreement between the calculated and experimental results across the entire liquidus is valid evidence in support of the model.展开更多
The electronic structures and field emission properties of capped CNT55 systems with or without alkali metal atom adsorption were systematically investigated by density functional theory calculation.The results indica...The electronic structures and field emission properties of capped CNT55 systems with or without alkali metal atom adsorption were systematically investigated by density functional theory calculation.The results indicate that the adsorption of alkali metal on the center site of a CNT tip is energetically favorable.In addition,the adsorption energies increase with the introduction of the electric field.The excessive negative charges on CNT tips make electron emittance much easier and result in a decrease in work function.Furthermore,the inducing effect by positively charged alkali metal atoms can be reasonably considered as the dominant reason for the improvement in field emission properties.展开更多
A semi-empirical atomic structure model method is developed in the framework of a relativistic case. This method starts from Dirac–Fock calculations using B-spline basis set. The core-valence electron correction is t...A semi-empirical atomic structure model method is developed in the framework of a relativistic case. This method starts from Dirac–Fock calculations using B-spline basis set. The core-valence electron correction is then treated in a semiempirical core polarization potential. As an application, the polarization properties of alkali metal atoms, including the static polarizabilities and long-range two-body dispersion coefficients, have been calculated. Our results are in good agreement with the results obtained from ab initio relativistic many-body perturbation method and the available experimental measurements.展开更多
A series of mesoporous smectite like materials incorporated with alkali metals such as Li, Na, K and Cs has been synthesized with the hydrothermal method. The crystalline and the pore structures of the materials synth...A series of mesoporous smectite like materials incorporated with alkali metals such as Li, Na, K and Cs has been synthesized with the hydrothermal method. The crystalline and the pore structures of the materials synthesized significantly change with the introduction of alkali metals. The addition of Li gives highly ordered layer phases, while the incorporation of Cs yields much less crystalline structures. Although Na or K has little effect on the crystalline structure, they modify the pore structure.展开更多
A microwave plasma torch(MPT) simultaneous spectrometer was used to study the spectral character and the matrix effect on alkali metal ions in solution. The main parameters were optimized. The microwave forward power ...A microwave plasma torch(MPT) simultaneous spectrometer was used to study the spectral character and the matrix effect on alkali metal ions in solution. The main parameters were optimized. The microwave forward power was 100 W. The argon flow rate that was used to sustain the Ar-MPT included the flow rate of carrier gas and the flow rate of support gas, which were 0.8 and 1.0 L/min, respectively. The HCl concentration in the solution was 0.02 {mol/L.} The observation height was 9.0 mm. The detection limits of Li, Na, K, Rb, and Cs were 0.0003, 0.0004, 0.009, 0.07 and 2.4 mg/L, respectively, and the results obtained by the Ar-MPT were compared with those obtained by argon inductively coupled plasma(Ar-ICP) and argon microwave induced plasma(Ar-MIP). The interference effects of several matrix elements were also studied.展开更多
基金financial support from European Union(Interreg FWVL V project PSYCHE)from the French National Research Agency(Multiprobe project,ANR-20-CE42-0007)。
文摘CO_(2)hydrogenation is an attractive way to store and utilize carbon dioxide generated by industrial processes,as well as to produce valuable chemicals from renewable and abundant resources.Iron catalysts are commonly used for the hydrogenation of carbon oxides to hydrocarbons.Iron-molybdenum catalysts have found numerous applications in catalysis,but have been never evaluated in the CO_(2)hydrogenation.In this work,the structural properties of iron-molybdenum catalysts without and with a promoting alkali metal(Li,Na,K,Rb,or Cs)were characterized using X-ray diffraction,hydrogen temperatureprogrammed reduction,CO_(2)temperature-programmed desorption,in-situ^(57)Fe Mossbauer spectroscopy and operando X-ray adsorption spectroscopy.Their catalytic performance was evaluated in the CO_(2)hydrogenation.During the reaction conditions,the catalysts undergo the formation of an iron(Ⅱ)molybdate structure,accompanied by a partial reduction of molybdenum and carbidization of iron.The rate of CO_(2)conversion and product selectivity strongly depend on the promoting alkali metals,and electronegativity was identified as an important factor affecting the catalytic performance.Higher CO_(2)conversion rates were observed with the promoters having higher electronegativity,while low electronegativity of alkali metals favors higher light olefin selectivity.
基金financial support from Natural Science Foundation of Inner Mongolia(No.2019MS05068)Inner Mongolia scientific and technological achievements transformation project(CGZH2018132)+3 种基金Inner Mongolia major science and technology project(2020ZD0024)the research project of Inner Mongolia Electric Power(Group)Co.,Ltd for post-doctoral studies,the Hong Kong Polytechnic University start-up funding,National Nature Science Foundation of China(No.51872157)Shenzhen Key Laboratory on Power Battery Safety Research(No.ZDSYS201707271615073)financial support from the Australian Research Council(DE190100445).
文摘The ever-growing pursuit of high energy density batteries has triggered extensive efforts toward developing alkali metal(Li,Na,and K)battery(AMB)technologies owing to high theoretical capacities and low redox potentials of metallic anodes.Typically,for new battery systems,the electrolyte design is critical for realizing the battery electrochemistry of AMBs.Conventional electrolytes in alkali ion batteries are generally unsuitable for sustaining the stability owing to the hyper-reactivity and dendritic growth of alkali metals.In this review,we begin with the fundamentals of AMB electrolytes.Recent advancements in concentrated and fluorinated electrolytes,as well as functional electrolyte additives for boosting the stability of Li metal batteries,are summarized and discussed with a special focus on structure-composition-performance relationships.We then delve into the electrolyte formulations for Na-and K metal batteries,including those in which Na/K do not adhere to the Li-inherited paradigms.Finally,the challenges and the future research needs in advanced electrolytes for AMB are highlighted.This comprehensive review sheds light on the principles for the rational design of promising electrolytes and offers new inspirations for developing stable AMBs with high performance.
基金support from the National Natural Science Foundation of China (52072257)the National Key Research and Development Program of China (2019YFE0118800).
文摘Alkali metal-carbon dioxide(Li/Na/K-CO_(2))batteries are emerging electrochemical energy storage technologies in the context of the energy crisis and the urgent demand for carbon neutrality.Alkali metal-CO_(2) batteries offer a new strategy for CO_(2) fixation and utilization,and thus has been receiving considerable attention in recent years.Considerable progress has been achieved since alkali metal-CO_(2) batteries were invented,especially in terms of development of new electrode materials,and yet,research is lacking on the underlying mechanisms of the systems.This is the first typical review focusing on the electrochemical mechanisms of metal-CO_(2) batteries that summarizes the current understanding of and provides insights into the thermodynamic reaction pathways,the kinetic characteristics,and the crucial factors determining the reaction mechanisms in alkali metal-CO_(2) batteries.The review starts with the fundamental concepts of alkali metal-CO_(2) batteries,followed by a comprehensive discussion of the working mechanisms on cathodes and anodes.Moreover,the operation mechanisms of state-of-the-art electrolytes,including liquid and(quasi-)solid-state electrolytes,are also described.Finally,we identify the unsolved problems in current alkali metal-CO_(2) batteries and propose potential topics for future research.
基金supported by NSFC(21473094 and21421001)MOE Innovation Team(IRT13022) in China
文摘Rechargeable alkali metal-air batteries are considered as the most promising candidate for the power source of electric vehicles(EVs) due to their high energy density. However, the practical application of metal-air batteries is still challenging. In the past decade, many strategies have been purposed and explored, which promoted the development of metal-air batteries. The reaction mechanisms have been gradually clarified and catalysts have been rationally designed for air cathodes. In this review, we summarize the recent development of alkali metal-air batteries from four parts: metal anodes, electrolytes, air cathodes and reactant gases, wherein we highlight the important achievement in this filed. Finally problems and prospective are discussed towards the future development of alkali metal-air batteries.
基金the National Natural Science Foundation of China(21476001)Key Project of Anhui Provincial Department of Education(KJ2017A045)are gratefully acknowledgedOpen Fund of Shaanxi Key Laboratory of Energy Chemical Process Intensification(No.SXECPI201601).
文摘The kinetics of coke solution loss reaction with and without sodium carbonate were investigated under the reaction atmosphere of carb on dioxide. The variables of gas flow rate and coke particle size were explored to eliminate the external and inteirial diffusion, respectively. Then, the improved method combining with the least square and the genetic algorithm was proposed to solve the homogeneous model and the shrinking core model. It was found that the improved genetic algorithm method has good stability by studying the fitness function at each generation. In the homogeneous model, the activation energy with and without sodium carbonate was 54.89 and 95.56 kJ/mol, respectively. And. the activation energy with and without sodium carbonate in the shrinking core model was 49.83 and 92.18 kJ/mol, respectively. Therefore, it was concluded that the sodium carbonate has the catalytic action. In addition, results showed that the estimated conversions were agreed well with the experimental ones, which indicated that the calculated kinetic parameters were valid and the proposed method was successfully developed.
基金The authors gratefully acknowledge the financial support provided by the 12th Five-Year Plan of National Science and Technology Support (Grant 2012BAA04B02)the National Natural Science Foundation of China (No.21406261).
文摘This work evaluated the effects of inherent alkali and alkaline earth metals on nitrogen transformation during steam gasification of Shengli lignite at the temperature of 873-1173 K in a fluidized-bed/fixed-bed quartz reactor. The results indicated that the alkali metal Na and alkaline earth metals Ca, Mg in coal have different effects on inherent nitrogen transformation to NH3, HCN and char-N during the lignite steam gasification. Specifically during the steam gasification of Shengli lignite, Na and Ca, Mg not only catalyze the inherent nitrogen conversions to NH3, but also promote the secondary reactions of the nascent char-N as well as the generation of NH3 from the generated HCN, meanwhile they also inhibited the inherent nitrogen conversion to HCN and char-N. The presence of Na, Ca and Mg hindered the formation of oxidized nitrogen (N-X) functional groups, but enhanced pyridinic nitrogen (N-6) and quaternary nitrogen's (N-Q) formation in char.
文摘EAB zeolite was successfully prepared and applied to selective adsorption of Li^(+),Na^(+)and K^(+)ions.The physical and chemical properties of the adsorbent were characterized by X-ray diffraction(XRD),X-ray fluorescence(XRF),scanning electron microscope(SEM)and thermogravimetry(TG)methods.The ion exchange behaviours for Li^(+),Na^(+)and K^(+)ions in monomcomponent and multicomponent solutions were studied.In independent ion exchange,the ion exchange capacities ratiosα(/Na/Li)andα(K/Li)were 3.8 and 6.2,respectively.In competitive ion exchange,the selectivitiesβ(Na/Li)andβ(K/Li)increased with the initial concentrations and reached 409 and 992 when the initial concentrations was 100 mmol/L.The thermodynamic study results showed that Gibbs free energy change(ΔGΘ)of ion exchange reaction between Li-EAB and K^(+)was-34.96 kJ/mol,indicating that ion exchange of K^(+)ions was more energetically favourable than Li^(+)ions.The calculation results showed that the energy barriers of ion exchange increased in the order K^(+)Na^(+)<Li^(+).The study shows that EAB zeolite is potential to be used in the separation of alkali ions.
基金the National Key R&D Research Program of China(Grant No.2018YFB0905400)the National Natural Science Foundation of China(Grant Nos.51872277,21606003,51902062,51972067,51802044,51925207 and U1910210)+2 种基金the Fundamental Research Funds for the Central Universities(WK2060140026)the DNL cooperation Fund,CAS(DNL180310)the Guangdong Natural Science Funds for Distinguished Young Scholar(Grant No.2019B151502039)。
文摘Alkali metal ion batteries(AMIBs)are playing an irreplaceable part in the energy revolution,due to their intrinsic advantages of large capacity/power density and abundance of alkali metal ions in the earth’s crust.Despite their great promise,the inborn deficiencies of commercial graphite and other anodes being researched so far call for the quest of better alternatives that exhibit all-round performance with the balance of energy/power density and cycling stability.Gallium-based materials,with impressive capacity utilization and self-healing ability,provide an anticipated solution to this conundrum.In this review,an overview on the recent progress of gallium-based anodes and their storage mechanism is presented.The current strategies used as engineering solutions to meet the scientific challenges ahead are discussed,in addition to the insightful outlook for possible future study.
基金support for this research from the Natural Science Foundation of China (U1261110)the Natural Science Foundation of Shanxi Province (20130110422)the Foundation of State Key Laboratory of Coal Combustion (FSKLCC-0914)
文摘The occurrence modes of alkali and alkaline-earth metals(AAEMs) in coal relate to their release behavior and ash formation during combustion. To better understand the transformation of AAEMs,the release behavior of water-soluble,HCl-soluble,HCl-insoluble AAEMs during Shenmu coal(SM coal) oxy-fuel combustion in the presence of SO2 and H2O in a drop-tube reactor was investigated through serial dissolution using H2O and HCl solutions. The results show that the release rates of AAEMs increase with an increase in temperature under the three atmospheres studied. The high release rates of Mg and Ca from SM coal are dependent on the high content of soluble Mg and Ca in SM coal. SO2 inhibits the release rates of AAEMs,while H2O promotes them. The effects of SO2 and H2O on the Na and K species are more evident than those on Mg and Ca species. All three types of AAEMs in coal can volatilize in the gas phase during coal combustion. The W-type AAEMs release excessively,whereas the release rates of I-type AAEMs are relatively lower. Different types of AAEM may interconvert through different pathways under certain conditions. Both SO2 and H2O promote the transformation reactions. The effect of SO2 was related to sulfate formation and the promotion by H2O occurs because of a decrease in the melting point of the solid as well as the reaction of H2O.
文摘Metal-organic frameworks(MOFs) have attracted much attention as adsorbents for the separation of CO2 from flue gas or natural gas. Here,a typical metal-organic framework HKUST-1(also named Cu-BTC or MOF-199) was chemically reduced by doping it with alkali metals(Li, Na and K) and they were further used to investigate their CO2 adsorption capacities. The structural information, surface chemistry and thermal behavior of the prepared adsorbent samples were characterized by X-ray powder diffraction(XRD), thermo-gravimetric analysis(TGA)and nitrogen adsorption-desorption isotherm analysis. The results showed that the CO2 storage capacity of HKUST-1 doped with moderate quantities of Li+, Na+and K+, individually, was greater than that of unmodified HKUST-1. The highest CO2 adsorption uptake of 8.64mmol/g was obtained with 1K-HKUST-1, and it was ca. 11% increase in adsorption capacity at 298 K and 18 bar as compared with HKUST-1. Moreover, adsorption tests showed that HKUST-1 and 1K-HKUST-1 displayed much higher adsorption capacities of CO2 than those of N2. Finally, the adsorption/desorption cycle experiment revealed that the adsorption performance of 1K-HKUST-1 was fairly stable, without obvious deterioration in the adsorption capacity of CO2 after 10 cycles.
基金the financial support from the 973 Programs of China(2013CBA01602)NSFC for Excellent Youth Scholars(51722304)+4 种基金NSFC(21720102002,21574080 and 61306018)Shanghai Committee of Science and Technology(15JC1490500,16JC1400703)and Open Project Program of the State Key Laboratory of Supramolecular Structure and Materials(sklssm201732,Jilin University)State Key Laboratory of Inorganic Synthesis and Preparative Chemistry(2016-08,Jilin University)State Key Laboratory for Mechanical Behavior of Materials(20161803,Xi’an Jiaotong University)
文摘With the increasing demand for large-scale battery systems in electric vehicles(EVs) and smart renewable energy grids, organic materials including small molecules and polymers utilized as electrodes in rechargeable batteries have received increasing attraction. In recent years, two-dimensional(2D) organic materials possessing planar layered architecture exhibit optional chemical modification, high specific surface area as well as unique electrical/magnetic properties, which have been emerging as the promising functional materials for wide applications in optoelectronics, catalysis, sensing, etc. Integrating with high-density redox-active sites and hierarchical porous structure, significant achievements in 2D organic materials as cathode materials for alkali-metal-ion batteries have been witnessed. In this review, the recent progress in synthetic approaches, structure analyses, electrochemical characterizations of 2D organic materials as well as their application in alkali-metal-ion batteries containing lithium ion battery(LIB), lithium sulfur battery(LSB), lithium air battery(LAB) and sodium ion battery(SIB) are summarized systematically,and their current challenges including cycling stability and electron conductivity for cathode materials in battery fields are also discussed.
文摘In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpressed as follows: GmE= xAxB[(λ11 +λ 12T) + (λ21 + λ22T)xB] The calculation of the model parameters. λ11 ,λ12, λ21 and λ22, was carried out numerically from the phase diagrams for 11 alkali metal-alkali halide or alkali earth metal-halide systems. In addition, artificial neural network trained by known data has been used to predict the values of these model parameters. The predicted results are in good agreement with the calculated ones. The applicability of the subregular solution model to the alkali metal-alkali halide or alkali earth metal-halide systems were tested by comparing the available experimental composition along the boundary of miscibility gap with the calculated ones which were obtained by using genetic algorithm. The good agreement between the calculated and experimental results across the entire liquidus is valid evidence in support of the model.
基金Project supported by the Key Program of the National Natural Science Foundation of China(Grant Nos.21031001 and U1034003)the National Natural Science Foundation of China(Grant Nos.20971040 and 21173072)the Cultivation Fund of the Key Scientific and Technical Innovation Project,Ministry of Education of China(Grant No.708029)
文摘The electronic structures and field emission properties of capped CNT55 systems with or without alkali metal atom adsorption were systematically investigated by density functional theory calculation.The results indicate that the adsorption of alkali metal on the center site of a CNT tip is energetically favorable.In addition,the adsorption energies increase with the introduction of the electric field.The excessive negative charges on CNT tips make electron emittance much easier and result in a decrease in work function.Furthermore,the inducing effect by positively charged alkali metal atoms can be reasonably considered as the dominant reason for the improvement in field emission properties.
基金supported by the National Basic Research Program of China(Grant No.2012CB821305)the National Natural Science Foundation of China(Grant Nos.11034009 and 11274246)
文摘A semi-empirical atomic structure model method is developed in the framework of a relativistic case. This method starts from Dirac–Fock calculations using B-spline basis set. The core-valence electron correction is then treated in a semiempirical core polarization potential. As an application, the polarization properties of alkali metal atoms, including the static polarizabilities and long-range two-body dispersion coefficients, have been calculated. Our results are in good agreement with the results obtained from ab initio relativistic many-body perturbation method and the available experimental measurements.
文摘A series of mesoporous smectite like materials incorporated with alkali metals such as Li, Na, K and Cs has been synthesized with the hydrothermal method. The crystalline and the pore structures of the materials synthesized significantly change with the introduction of alkali metals. The addition of Li gives highly ordered layer phases, while the incorporation of Cs yields much less crystalline structures. Although Na or K has little effect on the crystalline structure, they modify the pore structure.
文摘A microwave plasma torch(MPT) simultaneous spectrometer was used to study the spectral character and the matrix effect on alkali metal ions in solution. The main parameters were optimized. The microwave forward power was 100 W. The argon flow rate that was used to sustain the Ar-MPT included the flow rate of carrier gas and the flow rate of support gas, which were 0.8 and 1.0 L/min, respectively. The HCl concentration in the solution was 0.02 {mol/L.} The observation height was 9.0 mm. The detection limits of Li, Na, K, Rb, and Cs were 0.0003, 0.0004, 0.009, 0.07 and 2.4 mg/L, respectively, and the results obtained by the Ar-MPT were compared with those obtained by argon inductively coupled plasma(Ar-ICP) and argon microwave induced plasma(Ar-MIP). The interference effects of several matrix elements were also studied.
