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Mitigated reaction kinetics between lithium metal anodes and electrolytes by alloying lithium metal with low-content magnesium
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作者 Yang-Yang Wang Ya-Nan Wang +9 位作者 Nan Yao Shu-Yu Sun Xiao-Qing Ding Chen-Xi Bi Qian-Kui Zhang Zhao Zheng Cheng-Bin Jin Bo-Quan Li Xue-Qiang Zhang Jia-Qi Huang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期644-650,I0014,共8页
Lithium(Li)metal is regarded as a promising anode candidate for high-energy-density rechargeable batteries.Nevertheless,Li metal is highly reactive against electrolytes,leading to rapid decay of active Li metal reserv... Lithium(Li)metal is regarded as a promising anode candidate for high-energy-density rechargeable batteries.Nevertheless,Li metal is highly reactive against electrolytes,leading to rapid decay of active Li metal reservoir.Here,alloying Li metal with low-content magnesium(Mg)is proposed to mitigate the reaction kinetics between Li metal anodes and electrolytes.Mg atoms enter the lattice of Li atoms,forming solid solution due to the low amount(5 wt%)of Mg.Mg atoms mainly concentrate near the surface of Mg-alloyed Li metal anodes.The reactivity of Mg-alloyed Li metal is mitigated kinetically,which results from the electron transfer from Li to Mg atoms due to the electronegativity difference.Based on quantitative experimental analysis,the consumption rate of active Li and electrolytes is decreased by using Mgalloyed Li metal anodes,which increases the cycle life of Li metal batteries under demanding conditions.Further,a pouch cell(1.25 Ah)with Mg-alloyed Li metal anodes delivers an energy density of 340 Wh kg^(-1)and a cycle life of 100 cycles.This work inspires the strategy of modifying Li metal anodes to kinetically mitigate the side reactions with electrolytes. 展开更多
关键词 Lithium metal anodes ALLOYING Anode/electrolyte interface reaction kinetics Pouch cell
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Copper Indium Sulfide Enables Li-CO_(2)Batteries with Boosted Reaction Kinetics and Cycling Stability 被引量:1
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作者 Lin Chen Jingwen Zhou +3 位作者 Junxiang Zhang Guicai Qi Bin Wang Jianli Cheng 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第5期372-380,共9页
High energy density Li-CO_(2)batteries have attracted much attention owing to the"two birds with one stone"feature in fixing greenhouse gas CO_(2)and providing renewable energy.However,poor reversibility of ... High energy density Li-CO_(2)batteries have attracted much attention owing to the"two birds with one stone"feature in fixing greenhouse gas CO_(2)and providing renewable energy.However,poor reversibility of the discharge product Li_(2)CO_(3)is one of the main problems that limit its application,resulting in poor cycling stability and severe polarization.Herein,copper indium sulfide(CIS),a semiconducting non-precious metal sulfide,is fabricated as cathode catalysts for high-performance Li-CO_(2)batteries.Combined with the synergistic effect of bimetallic valence bonding and coordinated electron transfer,Li-CO_(2)batteries using CIS cathodes exhibit high full specific discharge capacity,excellent rate capability and cycle stability,namely it delivers a high specific full discharge capacity of 8878μAh cm^(-2),runs steadily from 10 to 100μA cm^(-2),and performs a stable long-term cycling behavior(>1050 h)under a high energy efficiency of 84%and a low charge voltage of approximately 3.4 V at 20μA cm^(-2)within 100μAh cm^(-2).In addition,a flexible Li-CO_(2)pouch cell is constructed to reveal the potential of employing CIS to fabricate flexible high energy storage devices in practical applications.This work shows a promising development pathway toward next-generation sustainable energy storage devices. 展开更多
关键词 copper indium sulfides cycling stability Li-CO_(2)batteries reaction kinetics
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Insight into pyrolysis of hydrophobic silica aerogels:Kinetics,reaction mechanism and effect on the aerogels
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作者 Xinyu Liu Hongliang Sheng +7 位作者 Song He Chunhua Du Yuansheng Ma Chichi Ruan Chunxiang He Huaming Dai Yajun Huang Yuelei Pan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第6期266-281,共16页
Silica aerogels have promising applications in thermal insulation,but their flammability and reaction mechanisms have rarely been investigated.The pyrolysis kinetics and thermodynamics of hydrophobic silica aerogels u... Silica aerogels have promising applications in thermal insulation,but their flammability and reaction mechanisms have rarely been investigated.The pyrolysis kinetics and thermodynamics of hydrophobic silica aerogels under N_(2) environment were studied.The kinetic and thermodynamic parameters were obtained by three model-free methods.Based on the calculated kinetic parameters,the pyrolysis mechanism of silica aerogels was discussed by the master plots method.The results indicate that the reactions of the whole pyrolysis phase can be characterized by a random nuclear model.In addition,FTIR test results show that the volatile products of silica aerogel pyrolysis are mainly hydrocarbons generated by the decomposition of hydrophobic groups(methyl groups)on the surface.Finally,the effects of pyrolysis on the properties of silica aerogels Finally,the effects of pyrolysis on the properties of silica aerogels were investigated based on the analysis results of SEM,specific surface area,pore size distribution,X-ray diffraction,XPS and infrared spectroscopy. 展开更多
关键词 PYROLYSIS THERMODYNAMICS reaction kinetics
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Study on the catalytic degradation of sodium lignosulfonate to aromatic aldehydes over nano-CuO:Process optimization and reaction kinetics
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作者 Yingjie Song Shuqi Zhong +5 位作者 Yingjiao Li Kun Dong Yong Luo Guangwen Chu Haikui Zou Baochang Sun 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第1期300-309,共10页
As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective... As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective technology to convert lignin like sodium lignosulfonate(SL),a lignin derivative,into aromatic aldehydes such as vanillin and syringaldehyde.However,how to improve the yield of aromatic aldehyde and conversion efficiency is still a challenge,and many operating conditions that significantly affect the yield of these aromatic compounds have rarely been investigated systematically.In this work,we adopted the stirred tank reactor(STR)for the CWAO process with nano-CuO as catalyst to achieve the conversion of SL into vanillin and syringaldehyde.The effect of operating conditions including reaction time,oxygen partial pressure,reaction temperature,SL concentration,rotational speed,catalyst amount,and NaOH concentration on the yield of single phenolic compound was systematically investigated.The results revealed that all these operating conditions exhibit a significant effect on the aromatic aldehyde yield.Therefore,they should be regulated in an optimal value to obtain high yield of these aldehydes.More importantly,the reaction kinetics of the lignin oxidation was explored.This work could provide basic data for the optimization and design of industrial operation of lignin oxidation. 展开更多
关键词 NANO-CUO Sodium lignosulfonate Catalytic wet aerobic oxidation(CWAO) Aromatic aldehyde reaction kinetics
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Kinetics of the direct reaction between ozone and phenol by high-gravity intensified heterogeneous catalytic ozonation
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作者 Kechang Gao Shengjuan Shao +3 位作者 Zhixing Li Jiaxin Jing Weizhou Jiao Youzhi Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第1期317-323,共7页
In this study,high-gravity intensified heterogeneous catalytic ozonation is utilized for treatment of phenol-containing wastewater,and the kinetics of the direct reaction between ozone and phenol in the presence of ex... In this study,high-gravity intensified heterogeneous catalytic ozonation is utilized for treatment of phenol-containing wastewater,and the kinetics of the direct reaction between ozone and phenol in the presence of excess tertiary butanol(TBA)is investigated.It is revealed that the direct reaction between ozone and phenol in the rotating packed bed(RPB)follows the pseudo-first-order kinetics with a reaction rate constant higher than that in the conventional bubbling reactor(BR).Under different conditions of temperature,initial pH,high-gravity factor,and gaseous ozone concentration,the apparent reaction rate constant varies in the range of 0.0160–0.115 min-1.An empirical power-exponential model is established to characterize the effects of these parameters on the direct reaction between ozone and phenol by high-gravity intensified heterogeneous catalytic ozonation. 展开更多
关键词 High-gravity technique Heterogeneous catalysis OZONE PHENOL kinetics of the direct reaction
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Modulation of Electronic States in Bimetallic-doped Nitrogen-Carbon Based Nanoparticles for Enhanced Oxygen Reduction Kinetics
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作者 Chen Gong Chenyu Yang +2 位作者 Wanlin Zhou Hui Su Qinghua Liu 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第4期513-521,I0042-I0060,I0094,共29页
Controlling the local electronic structure of active ingredients to improve the adsorption desorption characteristics of oxygen-containing intermediates over the electrochemical liquid-solid interfaces is a critical c... Controlling the local electronic structure of active ingredients to improve the adsorption desorption characteristics of oxygen-containing intermediates over the electrochemical liquid-solid interfaces is a critical challenge in the field of oxygen reduction reaction(ORR)catalysis.Here,we offer a simple approach for modulating the electronic states of metal nanocrystals by bimetal co-doping into carbon-nitrogen substrate,allowing us to modulate the electronic structure of catalytic active centers.To test our strategy,we designed a typical bimetallic nanoparticle catalyst(Fe-Co NP/NC)to flexibly alter the reaction kinetics of ORR.Our results from synchrotron Xray absorption spectroscopy and X-ray photoelectron spectroscopy showed that the co-doping of iron and cobalt could optimize the intrinsic charge distribution of Fe-Co NP/NC catalyst,promoting the oxygen reduction kinetics and ultimately achieving remarkable ORR activity.Consequently,the carefully designed Fe-Co NP/NC exhibits an ultra-high kinetic current density at the operating voltage(71.94 mA/cm^(2)at 0.80 V),and the half-wave potential achieves 0.915 V,which is obviously better than that of the corresponding controls including Fe NP/NC,Co NP/NC.Our findings provide a unique perspective for optimizing the electronic structure of active centers to achieve higher ORR catalytic activity and faster kinetics. 展开更多
关键词 Oxygen reduction reaction reaction kinetics Electronic state modulation CODOPING ELECTROCATALYSIS
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Approaching Ultimate Synthesis Reaction Rate of Ni-Rich Layered Cathodes for Lithium-Ion Batteries
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作者 Zhedong Liu Jingchao Zhang +9 位作者 Jiawei Luo Zhaoxin Guo Haoran Jiang Zekun Li Yuhang Liu Zijing Song Rui Liu Wei-Di Liu Wenbin Hu Yanan Chen 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第10期392-402,共11页
Nickel-rich layered oxide LiNi_(x)Co_(y)MnzO_(2)(NCM,x+y+z=1)is the most promising cathode material for high-energy lithium-ion batteries.However,conventional synthesis methods are limited by the slow heating rate,slu... Nickel-rich layered oxide LiNi_(x)Co_(y)MnzO_(2)(NCM,x+y+z=1)is the most promising cathode material for high-energy lithium-ion batteries.However,conventional synthesis methods are limited by the slow heating rate,sluggish reaction dynamics,high energy consumption,and long reaction time.To overcome these chal-lenges,we first employed a high-temperature shock(HTS)strategy for fast synthesis of the NCM,and the approaching ultimate reaction rate of solid phase transition is deeply investigated for the first time.In the HTS process,ultrafast average reaction rate of phase transition from Ni_(0.6)Co_(0.2)Mn_(0.2)(OH)_(2) to Li-containing oxides is 66.7(%s^(-1)),that is,taking only 1.5 s.An ultrahigh heating rate leads to fast reaction kinetics,which induces the rapid phase transition of NCM cathodes.The HTS-synthesized nickel-rich layered oxides perform good cycling performances(94%for NCM523,94%for NCM622,and 80%for NCM811 after 200 cycles at 4.3 V).These findings might also assist to pave the way for preparing effectively Ni-rich layered oxides for lithium-ion batteries. 展开更多
关键词 Nickel-rich layered oxides High-temperature shock Solid reaction kinetics Phase transition reaction rate
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Kinetics of the Reaction Between Ozone and Cationic Red X-GRL 被引量:6
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作者 赵伟荣 史惠祥 汪大翚 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第4期388-394,共7页
The ozonation of Cationic Red X-GRL in a semi-batch reactor was studied with variation of the gas flow rate, initial Cationic Red X-GRL concentration, temperature, and pH value. By the evaluation of the liquid mass tr... The ozonation of Cationic Red X-GRL in a semi-batch reactor was studied with variation of the gas flow rate, initial Cationic Red X-GRL concentration, temperature, and pH value. By the evaluation of the liquid mass transfer coefficient, the interfacial area, and the stoichiometric ratio between ozone and Cationic Red X-GRL, the rate constants and the kinetic regime of the reaction between ozone and Cationic Red X-GRL were investigated by applying the experimental data to a model based on the film mass transfer theory. The results obtained support a second order overall reaction, first order with respect to both ozone and dye, and the rate constants were correlated by a modified Arrhenius Equation of temperature and pH value with activation energy of 18.06kJ·mol-1. Hatta number of the reaction was found to be between 0.026 and 0.041, it indicates that the reaction occurs in the liquid bulk, corresponding to the slow kinetic regime. 展开更多
关键词 OZONATION Cationic Red X-GRL reaction kinetics DYE mass transfer
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Effect of montmorillonite on kinetics of polyurethane preparation reaction 被引量:5
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作者 You Cao Yu Jiang +3 位作者 Shu Lu Zhao Xiao Jun Cai Mei Long Hu Bing Liao 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第1期115-118,共4页
The prepolymerization and curing reaction kinetics of polyurethane/montmorillonite have been studied with end group analysis and FTIR respectively. It was found that the prepolymerization and curing reaction followed ... The prepolymerization and curing reaction kinetics of polyurethane/montmorillonite have been studied with end group analysis and FTIR respectively. It was found that the prepolymerization and curing reaction followed the 2nd-order kinetics. But the activation energy of prepolymerization increased from 42.7 kJ/mol to 56.5 kJ/rnol after the montmorillonite was added in the reaction system, and activation energy of curing reaction decreased from 64.4 kJ/mol to 17.5 kJ/mol. 2007 Bing Liao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. 展开更多
关键词 reaction kinetics reaction order Activation energy End group analysis FIIR
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Thermal Behavior,Nonisothermal Decomposition Reaction Kinetics of Mixed Ester Double-base Gun Propellants 被引量:6
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作者 YI Jian-hua ZHAO Feng-qi XU Si-yu GAO Hong-xu HU Rong-zu 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2008年第5期608-614,共7页
The thermal decomposition behavior and nonisothermal reaction kinetics of the double-base gun propellants containing the mixed ester of triethyleneglycol dinitrate(TEGDN) and nitroglycerin(NG) were investigated by... The thermal decomposition behavior and nonisothermal reaction kinetics of the double-base gun propellants containing the mixed ester of triethyleneglycol dinitrate(TEGDN) and nitroglycerin(NG) were investigated by thermogravimetry(TG) and differential thermogravimetry(DTG), and differential scanning calorimetry(DSC) under the high-pressure dynamic ambience. The results show that the thermal decomposition processes of the mixed nitric ester gun propellants have two mass-loss stages. Nitric ester evaporates and decomposes in the first stage, and nitrocellulose and centralite II(C2) decompose in the second stage. The mass loss, the DTG peak points, and the terminated temperatures of the two stages are changeable with the difference of the mass ratio of TEGDN to NG. There is only one obvious exothermic peak in the DSC curves under the different pressures. With the increase in the furnace pressure, the peak temperature decreases, and the decomposition heat increases. With the increase in the content of TEGDN, the decomposition heat decreases at 0.1 MPa and rises at high pressure. The variety of mass ratio of TEGDN to NG makes few effect on the exothermic peak temperatures in the DSC curves at different pressures. The kinetic equation of the main exothermal decomposition reaction of the gun propellant TG0601 was determined as: dα/dt=1021.59(1-α)3e-2.60×104/T. The reaction mechanism of the process can be classified as chemical reaction. The critical temperatures of the thermal explosion(Tbe and Tbp) obtained from the onset temperature(Te) and the peak temperature(Tp) are 456.46 and 473.40 K, respectively. ΔS≠, ΔH≠, and ΔG≠ of the decomposition reaction are 163.57 J·mol^-1·K^-1, 209.54 kJ·mol^-1, and 133.55 kJ·mol^-1, respectively. 展开更多
关键词 Mixed nitric ester gun propellant Triethyleneglycol dinitrate Thermal behaviors Nonisothermal decomposition reaction kinetics
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Kinetics and mechanism of titanium hydride powder and aluminum melt reaction 被引量:3
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作者 Ali Rasooli Mehdi Divandari +1 位作者 Hamid Reza Shahverdi Mohammad Ali Boutorabi 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第2期165-172,共8页
Based on the measurement of the released hydrogen gas pressure (PH2), the reaction kinetics between TiH2 powder and pure aluminum melt was studied at various temperatures. After cooling the samples, the interface of... Based on the measurement of the released hydrogen gas pressure (PH2), the reaction kinetics between TiH2 powder and pure aluminum melt was studied at various temperatures. After cooling the samples, the interface of TiH2 powder and aluminum melt was studied. The results show that the-time curves have three regions; in the first and second regions, the rate of reaction conforms zero and one order, respectively; in the third region, the hydrogen gas pressure remains constant and the rate of reaction reaches zero. The main factors that control the rate of reaction in the first and second regions are the penetration of hydrogen atoms in the titanium lattice and the chemical reaction between molten aluminum and titanium, respectively. According to the main factors that control the rate of reaction, three temperature ranges are considered for the reaction mechanism: (a) 700-750°C, (b) 750-800°C, and (c) 800-1000°C. In the first temperature range, the reaction is mostly under the control of chemical reaction; at the temperature range of 750 to 800°C, the reaction is controlled by the diffusion and chemical reaction; at the third temperature range (800-1000°C), the dominant controlling mechanism is diffusion. 展开更多
关键词 titanium hydride ALUMINUM reaction kinetics reaction rate constants
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Empirical correction of kinetic model for polymer thermal reaction process based on first order reaction kinetics 被引量:2
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作者 Zhaoxiang Zhang Fei Guo +2 位作者 Wei Song Xiaohong Jia Yuming Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第10期132-144,共13页
Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been derive.To make the model more applicable,the effects of time and the conversion degree on the reaction ra... Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been derive.To make the model more applicable,the effects of time and the conversion degree on the reaction rate parameters were considered.Two types of undetermined functions were used to compensate for the intrinsic variation of the reaction rate,and two types of correction methods are provided.The model was explained and verified using published experimental data of different polymer thermal reaction systems,and its effectiveness and wide adaptability were confirmed.For the given kinetic model,only one parameter needs to be determined.The proposed empirical model is expected to be used in the numerical simulation of polymer thermal reaction process. 展开更多
关键词 Thermal reaction Polymer processing reaction kinetics Mathematical modeling Empirical correction
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Synthesis of Toluene-2,4-Bisurea from 2,4-Toluene Diamine and Urea and the Reaction Kinetics 被引量:2
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作者 王娜 耿艳楼 +2 位作者 安华良 赵新强 王延吉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第8期927-932,共6页
Toluene-2,4-bisurea (TBU) is an important intermediate for urea route to dimethyl toluene-2,4-dicarbamate and the study on TBU synthesis via the reaction of 2,4-toluene diamine (TDA) and urea is of great significance.... Toluene-2,4-bisurea (TBU) is an important intermediate for urea route to dimethyl toluene-2,4-dicarbamate and the study on TBU synthesis via the reaction of 2,4-toluene diamine (TDA) and urea is of great significance. Firstly, thermodynamic analysis shows that the reaction is exothermic and a high equilibrium conversion of TDA is expected due to its large reaction equilibrium constant. Secondly, under the suitable reaction conditions, 130 °C, 7 h, and molar ratio of TDA/zinc acetate/urea/sulfolane 1/0.05/3.5/10, TDA conversion is 54.3%, and TBU yield and selectivity are 39.8% and 73.3% respectively. Lastly, the synthesis of TBU is a 1st order reaction with respect to TDA and the reaction kinetics model is established. This work will provide useful information for commercializing the urea route to toluene-2,4-dicarbamate (TDC). 展开更多
关键词 2 4-toluene diamine UREA toluene-2 4-bisurea reaction kinetics
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Mechanism and Kinetics Analysis of NO/SO_2/N_2/O_2 Dissociation Reactions in Non-Thermal Plasma 被引量:1
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作者 王心亮 李婷婷 +2 位作者 魏冬香 魏艳丽 顾璠 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第6期710-716,共7页
The kinetics mechanism of the dissociation reactions in a NO/SO2/N2/O2 system was investigated in consideration of energetic electrons' impacts on a non-thermal plasma. A model was derived from the Boltzmann equation... The kinetics mechanism of the dissociation reactions in a NO/SO2/N2/O2 system was investigated in consideration of energetic electrons' impacts on a non-thermal plasma. A model was derived from the Boltzmann equation and molecule collision theory to predict the dissociation reaction rate coefficients. Upon comparison with available literature, the model was confirmed to be acceptably accurate in general. Several reaction rate coefficients of the NO/SO2/N2/O2 dissociation system were derived according to the Arrhenius formula. The activation energies of each plasma reaction were calculated by quantum chemistry methods. The relation between the dissociation reaction rate coefficient and electron temperature was established to describe the importance of each reaction and to predict relevant processes of gaseous chemical reactions. The sensitivity of the mechanism of NO/SO2/N2/O2 dissociation reaction in a non-thermal plasma was also analysed. 展开更多
关键词 non-thermal plasma chemical reaction kinetics Boltzmann equation rate coefficient
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Decomposition reaction kinetics of Baotou RE concentrate with concentrated sulfuric acid at low temperature 被引量:3
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作者 WANG Xiuyan LIU Jiemin +2 位作者 LI Mei FAN Huili YANG Qishan 《Rare Metals》 SCIE EI CAS CSCD 2010年第2期121-125,共5页
Baotou RE concentrate was decomposed with concentrated sulfuric acid by controlling the roasting temperature below 500℃.Thermogravimetry-differential thermal analysis(TG-DTA) and chemical analytical methods were us... Baotou RE concentrate was decomposed with concentrated sulfuric acid by controlling the roasting temperature below 500℃.Thermogravimetry-differential thermal analysis(TG-DTA) and chemical analytical methods were used to study the thermal decomposition process and the thermal decomposition effect.The Freeman-Carroll method was applied to analyze the TG-DTA curves.The activation energy, reaction order, and reaction frequency factor at different stages were calculated.The Satava method was used to deduce the reaction mechanism and the relative reaction rate during the thermal decomposition process. 展开更多
关键词 roasting rare earths concentrate TG-DTA reaction kinetics
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Mapping the kinetics of hydrogen evolution reaction on Ag via pseudo-single-crystal scanning electrochemical cell microscopy 被引量:1
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作者 Yufei Wang Mingyang Li +1 位作者 Emma Gordon Hang Ren 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第12期3170-3176,共7页
Elucidating the structure-activity relationship in electrocatalysis is of fundamental interest for electrochemical energy conversion and storage.However,the heterogeneity in the surface structure of electrocatalysts,i... Elucidating the structure-activity relationship in electrocatalysis is of fundamental interest for electrochemical energy conversion and storage.However,the heterogeneity in the surface structure of electrocatalysts,including the presence of various facets,poses an analytical challenge in revealing the true structure-activity relationship because the activity is conventionally measured on ensemble,resulting in an averaged activity that cannot be unequivocally associated with a single structural motif.Scanning electrochemical cell microscopy(SECCM)[1]combined with colocalized electron backscatter diffraction(EBSD)offers a direct way to reveal the correlative local electrochemical and structural information.Herein,we measured the hydrogen evolution reaction(HER)activity on Ag and its dependence on the crystal orientation.From the combined EBSD and SECCM mapping,it is found that Ag grains closer to{111}show a higher exchange current density,while those closer to{110}show a lower Tafel slope.The Tafel slope is also found to decrease with the step density increase.The ability to measure the electrocatalytic activity under a high mass-transfer rate allows us to reveal the activity difference at a high current density(up to 200 mA/cm^(2)).The approach reported here can be expanded to other systems to reveal the nature of active sites of electrocatalysis. 展开更多
关键词 kinetics of hydrogen evolution reaction AG Pseudo-single-crystal Scanning electrochemical cell MICROSCOPY
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Reaction kinetics of isopropyl palmitate synthesis 被引量:1
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作者 付丽丽 白银鸽 +1 位作者 吕高志 蒋登高 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第8期1335-1339,共5页
In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalytic method. The liquid-phase diffusion effect on the reaction process was elimin... In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalytic method. The liquid-phase diffusion effect on the reaction process was eliminated by adjusting the stirring rate. The results showed that the two-step reaction followed a tetrahedral mechanism and conformed to second-order reaction kinetics. Nucleophilic attack on the carbonyl carbon afforded an intermediate, containing a tetrahedral carbon center. The intermediate ultimately decomposed by elimination of the leaving group, affording isopropyl palmitate. The experimental data were analyzed at different temperatures by the integral method. The kinetic equations of the each step were deduced, and the activation energy and frequency factor were obtained. Experiments were performed to verify the feasibility of kinetic equations, and the result showed that the kinetic equations were reliable. This study could be very signi ficant to both industrial application and determining the continuous production of isopropyl palmitate. 展开更多
关键词 Isopropyl palmitate reaction kinetics Chemical reaction Preparation Chloridization Palmitic acid
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STUDIES ON THE WITTIG REACTION(XIII): KINETICS OF THE PTC-WITTIG REACTIONS OF 2-BUTENYL METHYL-DIPHENYLPHOSPHONIUM SALT WITH SUBSTITUTED BEN2ALDEHYDES 被引量:1
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作者 Wen Fang HUANG Ming Wu DING +1 位作者 Wen Jing XIAO Tian Jie WU Institute of Organic Sgnthesis, Central China Normal University, Wuhan 430O70 Center of Analysis and Testing, Central China Normal University, Wuhan 430070 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第6期411-414,共4页
The kinetics of PTC-Wittig reaction between substituted aromatic aldehydes and 2-butenyl methyldiphenylphosphonium salt has been studied. The low reaction constant (ρ=0. 30) implies that these PTC-Wittig reactions ta... The kinetics of PTC-Wittig reaction between substituted aromatic aldehydes and 2-butenyl methyldiphenylphosphonium salt has been studied. The low reaction constant (ρ=0. 30) implies that these PTC-Wittig reactions take place through low polar intermediate. 展开更多
关键词 PTC XIII kinetics OF THE PTC-WITTIG reactionS OF 2-BUTENYL METHYL-DIPHENYLPHOSPHONIUM SALT WITH SUBSTITUTED BEN2ALDEHYDES STUDIES ON THE WITTIG reaction
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EFFECTIVE SOLUTION METHOD OF CHEMICAL REACTION KINETICS WITH DIFFUSE
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作者 吕和祥 邱崑玉 陈建峰 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第4期435-442,共8页
The time integration method with four-order accuracy, self-starting and implicit for the diffuse chemical reaction kinetics equation or the transient instantaneous temperature filed equation was presented. The example... The time integration method with four-order accuracy, self-starting and implicit for the diffuse chemical reaction kinetics equation or the transient instantaneous temperature filed equation was presented. The examples show that both accuracy and stability are better than Runge-Kutta method with four-order. The coefficients of the equation are stored with sparse matrix pattern, so an algorithm is presented which combines a compact storage scheme with reduced computation cost. The computation of the competitive and consecutive reaction in the rotating packed bed, taken as examples, shows that the method is effective. 展开更多
关键词 step-by-step integration DIFFUSE chemical reaction kinetics rotating packedbed MICRO-MIXING
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Reaction Kinetics for Heterogeneous Oxidation of Mn(III) ~Toluene
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作者 张彰 朱宪 《Journal of Shanghai University(English Edition)》 CAS 2002年第3期260-264,共5页
The reaction kinetics of the heterogeneous oxidation of toluene with Mn 3+ was studied by considering the effects of disproportionation of Mn 3+ in reaction system, a 'parallel' modulus was set up. A... The reaction kinetics of the heterogeneous oxidation of toluene with Mn 3+ was studied by considering the effects of disproportionation of Mn 3+ in reaction system, a 'parallel' modulus was set up. And then the concentration of Mn 3+ in disproportionation and the concentration of benzaldehyde in oxidation were respectively determined in turn, the rate constant, order and pseudo activation energy of the heterogeneous oxidation were obtained by mathematical deduction and the kinetic equation was concluded. In addition, the reaction mechanism was analyzed. It shows that the results are completely consistent with modulus. 展开更多
关键词 manganese (III) TOLUENE heterogeneous reaction reaction kinetics.
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