In this work, gas-phase chemistry of ruthenium and rhodium was studied using online isothermal chromatographyapparatus at low temperature coupled to the 252Cf SF source[1] at IMP (Fig. 1). Apart from the interferenceo...In this work, gas-phase chemistry of ruthenium and rhodium was studied using online isothermal chromatographyapparatus at low temperature coupled to the 252Cf SF source[1] at IMP (Fig. 1). Apart from the interferenceof precursor effect[2], 109?110Ru and 111?112Rh were chosen as the representative isotopes for the two elementsrespectively. An improved Monte Carlo molecular simulation program was compiled according to the gas-phasechemistry model[3], and was used in the optimization of the experimental condition. The adsorption enthalpies ofpentacarbonyl ruthenium and tetracarbonyl rhodium on the FEP surface were obtained.展开更多
The microscopic heterogeneity of pore-throat structures in tight sandstone is a crucial parameter for understanding the transport mechanism of fluid flow.In this work,we firstly developed the new procedure to characte...The microscopic heterogeneity of pore-throat structures in tight sandstone is a crucial parameter for understanding the transport mechanism of fluid flow.In this work,we firstly developed the new procedure to characterize the pore size distribution(PSD)and throat size distribution(TSD)by combining the nuclear magnetic resonance(NMR),cast thin section(CTS),and constant-rate mercury injection(CRMI)tests,and used the permeability estimated model to verify the full-scale PSD and TSD.Then,we respectively analyzed the fractal feature of the pore and throat,and characterized the heterogeneity of pores and throats.Finally,we elaborated the effect of the pore and throat heterogeneity on the gas-phase seepage capacity base on the analysis of the simple capillary tube model and gas-flooding experiment.The results showed that(1)The PSD and TSD of the tight sandstone sample ranged from 0.01 to 10 mm and from 0.1 to 57 mm,respectively,mainly contributed by the micropores and mesopores.Meanwhile,the permeability estimated by the PSD and TSD was consistent with the experimental permeability,and relative error was lower than 8%.(2)The PSD and TSD exhibited multifractal characteristics,and singularity strength range,Δα,could be used as the indicator for characterizing the heterogeneity of pore and throat.Furthermore,the throat of the sample showed stronger heterogeneity than that the pore.(3)The throats played an important role for the fluid transport in the tight sandstone,and the effect of the throat heterogeneity on the gas-phase seepage capacity was different under the lower and higher injection pressure.The macropores and micropores maybe respectively become the preferential migration pathways at the lower and higher injection pressure.In the end,the identification plate was established in our paper,and could be described the relationship among the throat heterogeneity,injection pressure,permeability and flow path of the gas phase in the tight sandstone.展开更多
MXenes,the most recent addition to the 2D material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical str...MXenes,the most recent addition to the 2D material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical strength,etc.This review begins by presenting MXenes,providing insights into their structural characteristics,synthesis methods,and surface functional groups.The review covers a thorough analysis of MXene surface properties,including surface chemistry and termination group impacts.The properties of MXenes are influenced by their synthesis,which can be fluorine-based or fluorinedependent.Fluorine-based synthesis techniques involve etching with fluorine-based reagents,mainly including HF or LiF/HCl,while fluorine-free methods include electrochemical etching,chemical vapor deposition(CVD),alkaline etching,Lewis acid-based etching,etc.These techniques result in the emergence of functional groups such as-F,-O,-OH,-Cl,etc.on the MXenes surface,depending on the synthesis method used.Properties of MXenes,such as electrical conductivity,electronic properties,catalytic activity,magnetic properties,mechanical strength,and chemical and thermal stability,are examined,and the role of functional groups in determining these properties is explored.The review delves into the diverse applications of MXenes,encompassing supercapacitors,battery materials,hydrogen storage,fuel cells,electromagnetic interference(EMI) shielding,pollutant removal,water purification,flexible electronics,sensors,additive manufacturing,catalysis,biomedical and healthcare fields,etc.Finally,this article outlines the challenges and opportunities in the current and future development of MXenes research,addressing various aspects such as synthesis scalability,etching challenges,and multifunctionality,and exploring novel applications.The review concludes with future prospects and conclusions envisioning the impact of MXenes on future technologies and innovation.展开更多
Integrating ideological and political theories teaching into the whole process of classroom teaching construction is a new requirement for implementing the fundamental task of cultivating people by virtue and playing ...Integrating ideological and political theories teaching into the whole process of classroom teaching construction is a new requirement for implementing the fundamental task of cultivating people by virtue and playing the role of collaborative education.In order to realize the seamless integration of inorganic and analytical chemistry courses and ideological and political education,this paper summarizes the current situation of ideological and political research on inorganic and analytical chemistry courses in three major databases in China(VIP,CNKI and Wanfang),and sorts out the knowledge points,ideological and political elements and educational goals according to the content of the course chapters,to provide a basic guarantee for the ideological and political education construction of the course.展开更多
P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phas...P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phases remains a necessity.Herein,we design a P2/O3-type Na_(0.76)Ni_(0.31)Zn_(0.07)Mn_(0.50)Ti_(0.12)0_(2)(NNZMT)with high chemical/electrochemical stability by enhancing the coupling between the two phases.For the first time,a unique Na*extraction is observed from a Na-rich O3 phase by a Na-poor P2 phase and systematically investigated.This process is facilitated by Zn^(2+)/Ti^(4+)dual doping and calcination condition regulation,allowing a higher Na*content in the P2 phase with larger Na^(+)transport channels and enhancing Na transport kinetics.Because of reduced Na^(+)in the O3 phase,which increases the difficulty of H^(+)/Na^(+) exchange,the hydrostability of the O3 phase in NNZMT is considerably improved.Furthermore,Zn^(2+)/Ti^(4+)presence in NNZMT synergistically regulates oxygen redox chemistry,which effectively suppresses O_(2)/CO_(2) gas release and electrolyte decomposition,and completely inhibits phase transitions above 4.0 V.As a result,NNZMT achieves a high discharge capacity of 144.8 mA h g^(-1) with a median voltage of 3.42 V at 20 mA g^(-1) and exhibits excellent cycling performance with a capacity retention of 77.3% for 1000 cycles at 2000 mA g^(-1).This study provides an effective strategy and new insights into the design of high-performance layered-oxide cathode materials with enhanced structure/interface stability forSIBs.展开更多
Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the ch...Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the chemical formation process and the ground water sulfur cycle that transpire after the coal mining activities.Based on studies of hydrochemistry and D,^(18)O-H_(2)O,^(34)S-SO_(4)isotopes,this study applied principal component analysis,ion ratio and other methods in its attempts to reveal the hydrogeochemical action and sulfur cycle in the subsidence area of Pingyu mining area.The study discovered that,in the studied area,precipitation provides the major supply of groundwater and the main water chemistry effects are dominated by oxidation dissolution of sulfide minerals as well as the dissolution of carbonate and silicate rocks.The sulfate in groundwater primarily originates from oxidation and dissolution of sulfide minerals in coal-bearing strata and human activities.The mixed sulfate formed by the oxidation of sulfide minerals and by human activities continuously recharges the groundwater,promoting the dissolution of carbonate rock and silicate rock in the process.展开更多
Using the 'lumped mechanism' and 'counting species' methods, we developed a condensed gas-phase chemical model based on a simplified one. The modified quasi-steady-state approximation (QSSA) scheme and...Using the 'lumped mechanism' and 'counting species' methods, we developed a condensed gas-phase chemical model based on a simplified one. The modified quasi-steady-state approximation (QSSA) scheme and the error redistribution mass conservation technique are adopted to solve the atmospheric chemistry kinetic equations. Results show that the condensed model can well simulate concentration variations of gas species such as SO2, NOX, O-3, H2O2 and conversion rates of SO2 and NOX transformation to H2SO4 and HNO3. These results are in good agreement with those from the simplified model. The conversion rates of SO2 and NOX under different initial concentrations and meteorological conditions are computed, and the results can be directly applied to regional acid deposition model.展开更多
Carbon dioxide transformation to fuels or chemicals provides an attractive approach for its utilization as feedstock and its emission reduction. Herein, we report a gas-phase electrocatalytic reduction of CO2 in an el...Carbon dioxide transformation to fuels or chemicals provides an attractive approach for its utilization as feedstock and its emission reduction. Herein, we report a gas-phase electrocatalytic reduction of CO2 in an electrolytic cell, constructed using phosphoric acid-doped polybenz- imidazole (PBI) membrane, which allowed operation at 170 ℃ Pt/C and PtMo/C with variable ratio of Pt/Mo were studied as the cathode catalysts. The results showed that PtMo/C catalysts significantly enhanced CO formation and inhibited CH4 formation compared with Pt/C catalyst. Characterization by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy revealed that most Mo species existed as MoO3 in PtMo/C catalysts and the interaction between Pt and MoOx was likely responsible for the enhanced CO formation rate although these bicomponent catalysts in general had a larger particle size than Pt/C catalyst.展开更多
The gas-phase synthesis of dimethyl carbonate (DMC) from methanol, carbon monoxide and oXygen has here Studied in a flow system at atomspheric Pressure. A series of Catalyst used in this reaCtion have been prepared an...The gas-phase synthesis of dimethyl carbonate (DMC) from methanol, carbon monoxide and oXygen has here Studied in a flow system at atomspheric Pressure. A series of Catalyst used in this reaCtion have been prepared and evaluated. The influence of trivared carbon supporters, alkaline metal Promoters and operation conditions on DMC opthesis reaction has been discussed. Under the conditions of 130℃, CO/O2=1 .96, SV=3340h-1, the space-time yield (STY) of DMC over PdCl2-CuCl2-CH3COOK/ac. catalyst is 217g/l-cat h,which is higher than what is published in the literatUre so far.展开更多
Developing of non-metallic catalyst to replace metal catalyst is a meaningful and challenging direction.In this work,the non-metallic catalyst was synthetized successfully by loading ionic liquid onto the silica surfa...Developing of non-metallic catalyst to replace metal catalyst is a meaningful and challenging direction.In this work,the non-metallic catalyst was synthetized successfully by loading ionic liquid onto the silica surface,which was applied for the gas-phase dehydrochlorination of 1,1,2,2-tetrachloroethane.The 12%TPPC/SiO2(wt%)showed the best results with the conversion of 1,1,2,2-tetrachloroethane reaching 100%.The selectivity of 1,1,2-trichloroethylene was 100%,and no deactivation was found during the evaluation period.The catalytic mechanism was investigated and possible reaction route was given,which was a reference for fabricating and design of solid base catalyst.展开更多
The performance of the single-stage anaerobic digestion of kitchen wastes was investigated in an anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO 2. The ASBR was operated at four chemical oxygen ...The performance of the single-stage anaerobic digestion of kitchen wastes was investigated in an anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO 2. The ASBR was operated at four chemical oxygen demand(COD) loading rates, 2.8, 5.1, 6.2 and 8.4 g/(L·d) respectively. The COD loading rate was increased with the TS concentration and HRT changing. At maximum COD loading rate of 8.4 g/(L·d), the COD, total solid(TS) removal rate and methane gas yield were 69%, 68% and 2.5 L/(L·d) respectively. The operation of the reactor with gas-phased absorb of CO 2 was stable in spite of the low pH(2.6—3.9) and high concentration of TS(142 g/L) of input mixture. The output volatile fatty acid(VFA) concentration was between 2.7—4.7 g/L and had no inhibition on the methanogenic microorganism. The reactor without gas-phased absorb of CO 2 became acidified when the total COD loading rate was increased to 5.1 g/(L·d). Stoichiometry of the methanogenesis for kitchen wastes showed a considerable amount of alkaline will be required to keep pH in the appropriate range for the methanogenic microorganism based on theoretical calculation. Gas-phased absorb of CO 2 effectively reduced the alkaline consumption, hence avoided excessive cation into the reactor.展开更多
Small-cell HSY-S zeolite prepared by the gas-phase ultra-stable method had been researched and developed,and industrial preparation tests of HSY-S have been successfully carried out for the first time.The acid resista...Small-cell HSY-S zeolite prepared by the gas-phase ultra-stable method had been researched and developed,and industrial preparation tests of HSY-S have been successfully carried out for the first time.The acid resistance of industrially prepared HSY-S was investigated by acid solutions with different pH values.The structures and properties of HSY-S and its acid-treated samples were characterized by XRD,XRF,BET,and IR.Results show that the HSY-S samples have the characteristics of high crystallinity,good stability,large specific surface area,and good acid resistance.展开更多
In this review,the history and outlook of gas-phase CO_(2)activation using single electrons,metal atoms,clusters(mainly metal hydride clusters),and molecules are discussed on both of the experimental and theoretical f...In this review,the history and outlook of gas-phase CO_(2)activation using single electrons,metal atoms,clusters(mainly metal hydride clusters),and molecules are discussed on both of the experimental and theoretical fronts.Although the development of bulk solid-state materials for the activation and conversion of CO_(2)into value-added products have enjoyed great success in the past several decades,this review focuses only on gas-phase studies,because isolated,well-defined gas-phase systems are ideally suited for high-resolution experiments using state-of-the-art spectrometric and spectroscopic techniques,and for simulations employing modern quantum theoretical methods.The unmatched high complementarity and comparability of experiment and theory in the case of gas-phase investigations bear an enormous potential in providing insights in the reactions of CO_(2)activation at the atomic level.In all of these examples,the reduction and bending of the inert neutral CO_(2)molecule is the critical step determined by the frontier orbitals of reaction participants.Based on the results and outlook summarized in this review,we anticipate that studies of gas-phase CO_(2)activations will be an avenue rich with opportunities for the rational design of novel catalysts based on the knowledge obtained on the atomic level.展开更多
The booming wearable/portable electronic devices industry has stimulated the progress of supporting flexible energy storage devices.Excellent performance of flexible devices not only requires the component units of ea...The booming wearable/portable electronic devices industry has stimulated the progress of supporting flexible energy storage devices.Excellent performance of flexible devices not only requires the component units of each device to maintain the original performance under external forces,but also demands the overall device to be flexible in response to external fields.However,flexible energy storage devices inevitably occur mechanical damages(extrusion,impact,vibration)/electrical damages(overcharge,over-discharge,external short circuit)during longterm complex deformation conditions,causing serious performance degradation and safety risks.Inspired by the healing phenomenon of nature,endowing energy storage devices with self-healing capability has become a promising strategy to effectively improve the durability and functionality of devices.Herein,this review systematically summarizes the latest progress in intrinsic self-healing chemistry for energy storage devices.Firstly,the main intrinsic self-healing mechanism is introduced.Then,the research situation of electrodes,electrolytes,artificial interface layers and integrated devices based on intrinsic self-healing and advanced characterization technology is reviewed.Finally,the current challenges and perspective are provided.We believe this critical review will contribute to the development of intrinsic self-healing chemistry in the flexible energy storage field.展开更多
All-solid-state lithium metal batteries(ASSLMBs)are considered as one of the ultimate goals for the development of energy storage systems due to their high energy density and high safety.However,the mismatching of int...All-solid-state lithium metal batteries(ASSLMBs)are considered as one of the ultimate goals for the development of energy storage systems due to their high energy density and high safety.However,the mismatching of interface transport kinetics as well as interfacial instability induces the growth of lithium dendrite and thus,leads to severe degradation of battery electrochemical performances.Herein,an integrated interface configuration(IIC)consisting of in-situ generated Li I interphase and Li-Ag alloy anode is proposed through in-situ interface chemistry.The IIC is capable of not only regulating charge transport kinetics but also synchronously stabilizing the lithium/electrolyte interface,thereby achieving uniform lithium platting.Therefore,Li||Li symmetric cells with IIC achieve a critical current density of up to 1.6 mA cm^(-2)and achieve stable cycling over 1600 hours at a high current density of 0.5 mA cm^(-2).Moreover,a high discharge capacity of 140.1 mA h g-1at 0.1 C is also obtained for the Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)(NCM622)full battery with a capacity retention of 65.6%after 300 cycles.This work provides an effective method to synergistically regulate the interface transport kinetics and inhibit lithium dendrite growth for high-performance ASSLMBs.展开更多
Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 ...Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 on air pollution(only papers included in the Web of Science Core Collection database were considered),more than 24000 papers were authored or co-authored by scientists working in China.In this paper,we review a limited number of representative and significant studies on atmospheric chemistry in China in the last few years,including studies on(1)sources and emission inventories,(2)atmospheric chemical processes,(3)interactions of air pollution with meteorology,weather and climate,(4)interactions between the biosphere and atmosphere,and(5)data assimilation.The intention was not to provide a complete review of all progress made in the last few years,but rather to serve as a starting point for learning more about atmospheric chemistry research in China.The advances reviewed in this paper have enabled a theoretical framework for the air pollution complex to be established,provided robust scientific support to highly successful air pollution control policies in China,and created great opportunities in education,training,and career development for many graduate students and young scientists.This paper further highlights that developing and low-income countries that are heavily affected by air pollution can benefit from these research advances,whilst at the same time acknowledging that many challenges and opportunities still remain in atmospheric chemistry research in China,to hopefully be addressed over the next few decades.展开更多
NO_x-catalyzed oxidation of methane without a solid catalyst wasinvestigated, and a hydrogen selectivity of 27% was obtained with an overall methane conversion of34% and a free O_2 concentration of 1.7% at 700℃.
文摘In this work, gas-phase chemistry of ruthenium and rhodium was studied using online isothermal chromatographyapparatus at low temperature coupled to the 252Cf SF source[1] at IMP (Fig. 1). Apart from the interferenceof precursor effect[2], 109?110Ru and 111?112Rh were chosen as the representative isotopes for the two elementsrespectively. An improved Monte Carlo molecular simulation program was compiled according to the gas-phasechemistry model[3], and was used in the optimization of the experimental condition. The adsorption enthalpies ofpentacarbonyl ruthenium and tetracarbonyl rhodium on the FEP surface were obtained.
基金financial support from the Youth Science and Technology Innovation Team of Southwest Petroleum University(No.2018CXTD10)the National Natural Science Foundation Project of China(No.51874248 and No.U19B2010).
文摘The microscopic heterogeneity of pore-throat structures in tight sandstone is a crucial parameter for understanding the transport mechanism of fluid flow.In this work,we firstly developed the new procedure to characterize the pore size distribution(PSD)and throat size distribution(TSD)by combining the nuclear magnetic resonance(NMR),cast thin section(CTS),and constant-rate mercury injection(CRMI)tests,and used the permeability estimated model to verify the full-scale PSD and TSD.Then,we respectively analyzed the fractal feature of the pore and throat,and characterized the heterogeneity of pores and throats.Finally,we elaborated the effect of the pore and throat heterogeneity on the gas-phase seepage capacity base on the analysis of the simple capillary tube model and gas-flooding experiment.The results showed that(1)The PSD and TSD of the tight sandstone sample ranged from 0.01 to 10 mm and from 0.1 to 57 mm,respectively,mainly contributed by the micropores and mesopores.Meanwhile,the permeability estimated by the PSD and TSD was consistent with the experimental permeability,and relative error was lower than 8%.(2)The PSD and TSD exhibited multifractal characteristics,and singularity strength range,Δα,could be used as the indicator for characterizing the heterogeneity of pore and throat.Furthermore,the throat of the sample showed stronger heterogeneity than that the pore.(3)The throats played an important role for the fluid transport in the tight sandstone,and the effect of the throat heterogeneity on the gas-phase seepage capacity was different under the lower and higher injection pressure.The macropores and micropores maybe respectively become the preferential migration pathways at the lower and higher injection pressure.In the end,the identification plate was established in our paper,and could be described the relationship among the throat heterogeneity,injection pressure,permeability and flow path of the gas phase in the tight sandstone.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(NRF-2020R1A6A1A03043435 and 2020R1A2C1099862)supported by the Korea Institute for Advancement of Technology(KIAT)grant funded by the Korean Government(MOTIE)(P0012451,The Competency Development Program for Industry Specialist)。
文摘MXenes,the most recent addition to the 2D material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical strength,etc.This review begins by presenting MXenes,providing insights into their structural characteristics,synthesis methods,and surface functional groups.The review covers a thorough analysis of MXene surface properties,including surface chemistry and termination group impacts.The properties of MXenes are influenced by their synthesis,which can be fluorine-based or fluorinedependent.Fluorine-based synthesis techniques involve etching with fluorine-based reagents,mainly including HF or LiF/HCl,while fluorine-free methods include electrochemical etching,chemical vapor deposition(CVD),alkaline etching,Lewis acid-based etching,etc.These techniques result in the emergence of functional groups such as-F,-O,-OH,-Cl,etc.on the MXenes surface,depending on the synthesis method used.Properties of MXenes,such as electrical conductivity,electronic properties,catalytic activity,magnetic properties,mechanical strength,and chemical and thermal stability,are examined,and the role of functional groups in determining these properties is explored.The review delves into the diverse applications of MXenes,encompassing supercapacitors,battery materials,hydrogen storage,fuel cells,electromagnetic interference(EMI) shielding,pollutant removal,water purification,flexible electronics,sensors,additive manufacturing,catalysis,biomedical and healthcare fields,etc.Finally,this article outlines the challenges and opportunities in the current and future development of MXenes research,addressing various aspects such as synthesis scalability,etching challenges,and multifunctionality,and exploring novel applications.The review concludes with future prospects and conclusions envisioning the impact of MXenes on future technologies and innovation.
基金Supported by 2020 Teaching Reform Research Project of Pingdingshan University(2020-JY05)School-level Ideological and Political Demonstration Course of Pingdingshan University in 2023-Ecological Engineering+1 种基金Science and Technology Research Project of Henan Provincial Department of Science and Technology(212102110189)High-level Talent Start-up Fund Project of Pingdingshan University(PXY-BSQD-202001).
文摘Integrating ideological and political theories teaching into the whole process of classroom teaching construction is a new requirement for implementing the fundamental task of cultivating people by virtue and playing the role of collaborative education.In order to realize the seamless integration of inorganic and analytical chemistry courses and ideological and political education,this paper summarizes the current situation of ideological and political research on inorganic and analytical chemistry courses in three major databases in China(VIP,CNKI and Wanfang),and sorts out the knowledge points,ideological and political elements and educational goals according to the content of the course chapters,to provide a basic guarantee for the ideological and political education construction of the course.
基金supported by the National Natural Science Foundation of China (22169002)the Chongzuo Key Research and Development Program of China (20220603)the Counterpart Aid Project for Discipline Construction from Guangxi University(2023M02)
文摘P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phases remains a necessity.Herein,we design a P2/O3-type Na_(0.76)Ni_(0.31)Zn_(0.07)Mn_(0.50)Ti_(0.12)0_(2)(NNZMT)with high chemical/electrochemical stability by enhancing the coupling between the two phases.For the first time,a unique Na*extraction is observed from a Na-rich O3 phase by a Na-poor P2 phase and systematically investigated.This process is facilitated by Zn^(2+)/Ti^(4+)dual doping and calcination condition regulation,allowing a higher Na*content in the P2 phase with larger Na^(+)transport channels and enhancing Na transport kinetics.Because of reduced Na^(+)in the O3 phase,which increases the difficulty of H^(+)/Na^(+) exchange,the hydrostability of the O3 phase in NNZMT is considerably improved.Furthermore,Zn^(2+)/Ti^(4+)presence in NNZMT synergistically regulates oxygen redox chemistry,which effectively suppresses O_(2)/CO_(2) gas release and electrolyte decomposition,and completely inhibits phase transitions above 4.0 V.As a result,NNZMT achieves a high discharge capacity of 144.8 mA h g^(-1) with a median voltage of 3.42 V at 20 mA g^(-1) and exhibits excellent cycling performance with a capacity retention of 77.3% for 1000 cycles at 2000 mA g^(-1).This study provides an effective strategy and new insights into the design of high-performance layered-oxide cathode materials with enhanced structure/interface stability forSIBs.
基金supported by Geological Research Project of the Construction Management Bureau of the Middle Route of the South to North Water Diversion Project(ZXJ/HN/YW/GC-2020037)。
文摘Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the chemical formation process and the ground water sulfur cycle that transpire after the coal mining activities.Based on studies of hydrochemistry and D,^(18)O-H_(2)O,^(34)S-SO_(4)isotopes,this study applied principal component analysis,ion ratio and other methods in its attempts to reveal the hydrogeochemical action and sulfur cycle in the subsidence area of Pingyu mining area.The study discovered that,in the studied area,precipitation provides the major supply of groundwater and the main water chemistry effects are dominated by oxidation dissolution of sulfide minerals as well as the dissolution of carbonate and silicate rocks.The sulfate in groundwater primarily originates from oxidation and dissolution of sulfide minerals in coal-bearing strata and human activities.The mixed sulfate formed by the oxidation of sulfide minerals and by human activities continuously recharges the groundwater,promoting the dissolution of carbonate rock and silicate rock in the process.
文摘Using the 'lumped mechanism' and 'counting species' methods, we developed a condensed gas-phase chemical model based on a simplified one. The modified quasi-steady-state approximation (QSSA) scheme and the error redistribution mass conservation technique are adopted to solve the atmospheric chemistry kinetic equations. Results show that the condensed model can well simulate concentration variations of gas species such as SO2, NOX, O-3, H2O2 and conversion rates of SO2 and NOX transformation to H2SO4 and HNO3. These results are in good agreement with those from the simplified model. The conversion rates of SO2 and NOX under different initial concentrations and meteorological conditions are computed, and the results can be directly applied to regional acid deposition model.
基金supported by the Ministry of Science and Technology of China(Grant No:2012CB215500 and 2013CB933100)the National Natural Science Foundation of China(Grant No:21103178 and 21033009)
文摘Carbon dioxide transformation to fuels or chemicals provides an attractive approach for its utilization as feedstock and its emission reduction. Herein, we report a gas-phase electrocatalytic reduction of CO2 in an electrolytic cell, constructed using phosphoric acid-doped polybenz- imidazole (PBI) membrane, which allowed operation at 170 ℃ Pt/C and PtMo/C with variable ratio of Pt/Mo were studied as the cathode catalysts. The results showed that PtMo/C catalysts significantly enhanced CO formation and inhibited CH4 formation compared with Pt/C catalyst. Characterization by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy revealed that most Mo species existed as MoO3 in PtMo/C catalysts and the interaction between Pt and MoOx was likely responsible for the enhanced CO formation rate although these bicomponent catalysts in general had a larger particle size than Pt/C catalyst.
文摘The gas-phase synthesis of dimethyl carbonate (DMC) from methanol, carbon monoxide and oXygen has here Studied in a flow system at atomspheric Pressure. A series of Catalyst used in this reaCtion have been prepared and evaluated. The influence of trivared carbon supporters, alkaline metal Promoters and operation conditions on DMC opthesis reaction has been discussed. Under the conditions of 130℃, CO/O2=1 .96, SV=3340h-1, the space-time yield (STY) of DMC over PdCl2-CuCl2-CH3COOK/ac. catalyst is 217g/l-cat h,which is higher than what is published in the literatUre so far.
基金financed by the National Natural Science Foundation of China(NSFC-21476207,91534114,21776256)。
文摘Developing of non-metallic catalyst to replace metal catalyst is a meaningful and challenging direction.In this work,the non-metallic catalyst was synthetized successfully by loading ionic liquid onto the silica surface,which was applied for the gas-phase dehydrochlorination of 1,1,2,2-tetrachloroethane.The 12%TPPC/SiO2(wt%)showed the best results with the conversion of 1,1,2,2-tetrachloroethane reaching 100%.The selectivity of 1,1,2-trichloroethylene was 100%,and no deactivation was found during the evaluation period.The catalytic mechanism was investigated and possible reaction route was given,which was a reference for fabricating and design of solid base catalyst.
文摘The performance of the single-stage anaerobic digestion of kitchen wastes was investigated in an anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO 2. The ASBR was operated at four chemical oxygen demand(COD) loading rates, 2.8, 5.1, 6.2 and 8.4 g/(L·d) respectively. The COD loading rate was increased with the TS concentration and HRT changing. At maximum COD loading rate of 8.4 g/(L·d), the COD, total solid(TS) removal rate and methane gas yield were 69%, 68% and 2.5 L/(L·d) respectively. The operation of the reactor with gas-phased absorb of CO 2 was stable in spite of the low pH(2.6—3.9) and high concentration of TS(142 g/L) of input mixture. The output volatile fatty acid(VFA) concentration was between 2.7—4.7 g/L and had no inhibition on the methanogenic microorganism. The reactor without gas-phased absorb of CO 2 became acidified when the total COD loading rate was increased to 5.1 g/(L·d). Stoichiometry of the methanogenesis for kitchen wastes showed a considerable amount of alkaline will be required to keep pH in the appropriate range for the methanogenic microorganism based on theoretical calculation. Gas-phased absorb of CO 2 effectively reduced the alkaline consumption, hence avoided excessive cation into the reactor.
基金The authors gratefully acknowledge the funding of the project by SINOPEC(No.118001-6).
文摘Small-cell HSY-S zeolite prepared by the gas-phase ultra-stable method had been researched and developed,and industrial preparation tests of HSY-S have been successfully carried out for the first time.The acid resistance of industrially prepared HSY-S was investigated by acid solutions with different pH values.The structures and properties of HSY-S and its acid-treated samples were characterized by XRD,XRF,BET,and IR.Results show that the HSY-S samples have the characteristics of high crystallinity,good stability,large specific surface area,and good acid resistance.
基金National Key R&D Program of China(2018YFE0115000)the National Natural Science Foundation of China(22003027 and 22174073)+2 种基金the NSF of Tianjin City(19JCYBJC19600)the Frontiers Science Center for New Organic Matter of Nankai University(63181206)supported by the Air Force Office of Scientific Research(AFOSR)under grant number,FA9550-19-1-0077(KHB)。
文摘In this review,the history and outlook of gas-phase CO_(2)activation using single electrons,metal atoms,clusters(mainly metal hydride clusters),and molecules are discussed on both of the experimental and theoretical fronts.Although the development of bulk solid-state materials for the activation and conversion of CO_(2)into value-added products have enjoyed great success in the past several decades,this review focuses only on gas-phase studies,because isolated,well-defined gas-phase systems are ideally suited for high-resolution experiments using state-of-the-art spectrometric and spectroscopic techniques,and for simulations employing modern quantum theoretical methods.The unmatched high complementarity and comparability of experiment and theory in the case of gas-phase investigations bear an enormous potential in providing insights in the reactions of CO_(2)activation at the atomic level.In all of these examples,the reduction and bending of the inert neutral CO_(2)molecule is the critical step determined by the frontier orbitals of reaction participants.Based on the results and outlook summarized in this review,we anticipate that studies of gas-phase CO_(2)activations will be an avenue rich with opportunities for the rational design of novel catalysts based on the knowledge obtained on the atomic level.
基金supported by China Postdoctoral Science Foundation(2022M710951,2022TQ0087)Postdoctoral Science Foundation of Heilongjiang Province(LBH-Z22111)。
文摘The booming wearable/portable electronic devices industry has stimulated the progress of supporting flexible energy storage devices.Excellent performance of flexible devices not only requires the component units of each device to maintain the original performance under external forces,but also demands the overall device to be flexible in response to external fields.However,flexible energy storage devices inevitably occur mechanical damages(extrusion,impact,vibration)/electrical damages(overcharge,over-discharge,external short circuit)during longterm complex deformation conditions,causing serious performance degradation and safety risks.Inspired by the healing phenomenon of nature,endowing energy storage devices with self-healing capability has become a promising strategy to effectively improve the durability and functionality of devices.Herein,this review systematically summarizes the latest progress in intrinsic self-healing chemistry for energy storage devices.Firstly,the main intrinsic self-healing mechanism is introduced.Then,the research situation of electrodes,electrolytes,artificial interface layers and integrated devices based on intrinsic self-healing and advanced characterization technology is reviewed.Finally,the current challenges and perspective are provided.We believe this critical review will contribute to the development of intrinsic self-healing chemistry in the flexible energy storage field.
基金supported by the Beijing Natural Science Foundation(L223009)the National Natural Science Foundation of China(22075029)+1 种基金the National Key Research and Development Program of China(2021YFB2500300)the Key Research and Development(R&D)Projects of Shanxi Province(2021020660301013)。
文摘All-solid-state lithium metal batteries(ASSLMBs)are considered as one of the ultimate goals for the development of energy storage systems due to their high energy density and high safety.However,the mismatching of interface transport kinetics as well as interfacial instability induces the growth of lithium dendrite and thus,leads to severe degradation of battery electrochemical performances.Herein,an integrated interface configuration(IIC)consisting of in-situ generated Li I interphase and Li-Ag alloy anode is proposed through in-situ interface chemistry.The IIC is capable of not only regulating charge transport kinetics but also synchronously stabilizing the lithium/electrolyte interface,thereby achieving uniform lithium platting.Therefore,Li||Li symmetric cells with IIC achieve a critical current density of up to 1.6 mA cm^(-2)and achieve stable cycling over 1600 hours at a high current density of 0.5 mA cm^(-2).Moreover,a high discharge capacity of 140.1 mA h g-1at 0.1 C is also obtained for the Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)(NCM622)full battery with a capacity retention of 65.6%after 300 cycles.This work provides an effective method to synergistically regulate the interface transport kinetics and inhibit lithium dendrite growth for high-performance ASSLMBs.
基金funded by the National Natural Science Foundation of China(Grant No.91844000)。
文摘Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 on air pollution(only papers included in the Web of Science Core Collection database were considered),more than 24000 papers were authored or co-authored by scientists working in China.In this paper,we review a limited number of representative and significant studies on atmospheric chemistry in China in the last few years,including studies on(1)sources and emission inventories,(2)atmospheric chemical processes,(3)interactions of air pollution with meteorology,weather and climate,(4)interactions between the biosphere and atmosphere,and(5)data assimilation.The intention was not to provide a complete review of all progress made in the last few years,but rather to serve as a starting point for learning more about atmospheric chemistry research in China.The advances reviewed in this paper have enabled a theoretical framework for the air pollution complex to be established,provided robust scientific support to highly successful air pollution control policies in China,and created great opportunities in education,training,and career development for many graduate students and young scientists.This paper further highlights that developing and low-income countries that are heavily affected by air pollution can benefit from these research advances,whilst at the same time acknowledging that many challenges and opportunities still remain in atmospheric chemistry research in China,to hopefully be addressed over the next few decades.
基金The project supported by the Ministry of Science and Technology China(G1999022202).
文摘NO_x-catalyzed oxidation of methane without a solid catalyst wasinvestigated, and a hydrogen selectivity of 27% was obtained with an overall methane conversion of34% and a free O_2 concentration of 1.7% at 700℃.