An efficient copper-catalyzed regioselective acyloxy-trifluoromethylation of allenamides using Togni'sⅡreagent as the source of both the trifluoromethyl and acyloxy moieties was developed to create a workable rou...An efficient copper-catalyzed regioselective acyloxy-trifluoromethylation of allenamides using Togni'sⅡreagent as the source of both the trifluoromethyl and acyloxy moieties was developed to create a workable route to CF_(3)-substituted allylic esters.The reaction exhibited good functional group tolerance and high efficiency,affording the products in moderate to good yields.Mechanistic investigations indicated a radical process was likely involved in this transformation.展开更多
The degradation of partially hydrolyzed polyacrylamide(HPAM) found in alkaline/surfactant/polymer flooding sewage was investigated using Fenton-type reagents. Different Fenton reagent treatments for HPAM degradation w...The degradation of partially hydrolyzed polyacrylamide(HPAM) found in alkaline/surfactant/polymer flooding sewage was investigated using Fenton-type reagents. Different Fenton reagent treatments for HPAM degradation were compared. The effects of pH, hydrogen peroxide(H_(2)O_(2)), ferrous ion(Fe^(2+)), and tartaric ion(C_(4)H_(4)O_(6)^(2-)) concentrations were studied. The degradation reaction occurred within a wide range of pH(3–9). The HPAM degradation performance of photo-Fenton processes using solar light and UV were compared with that of the Fenton process. The degradation rate was found to be strongly dependent on the H_(2)O_(2)/Fe^(2+)/C_(4)H_(4)O_(6)^(2-)molar ratio. The HPAM degradation efficiency was 90%, and the chemical oxygen demand removal efficiency was 85%. HPAM could be degraded into a compound with a lower molecular weight, but it was difficult to achieve complete mineralization to CO_(2). The presence of intermediate products hindered further oxidation in the Fenton process.展开更多
Lithium ion capacitors(LICs)have been widely used as energy storage devices due to their high energy density and high power density.For LICs,pre-lithiation of negative electrode is necessary.In this work,we employ a b...Lithium ion capacitors(LICs)have been widely used as energy storage devices due to their high energy density and high power density.For LICs,pre-lithiation of negative electrode is necessary.In this work,we employ a bifunctional Li6CoO4(LCO)as cathodic pre-lithiation reagent to improve the electrochemical performance of LICs.The synthesized LCO exhibited high first charge specific capacity of 721 mAh g-1and extremely low initial coulombic efficiency of 3.19%,providing sufficient Li+ for the pre-lithiation of negative electrode in the first charge.Simultaneously,Li6–xCoOy is generated from LCO during the first charge process,which exhibits pseudocapacitive property and contributes to capacity in form of surface capacitance during subsequent cycles,increasing the capacity of capacitive positive electrode.With the appropriate amounts of addition to the positive side in LICs,this bifunctional prelithiation reagent LCO shows significantly improved the electrochemical performance with the energy density of 78.5 Wh kg-1after 300 cycles between 2.0 and 4.2 V at 250 mA g-1.展开更多
Heterogeneous Fenton reagent, as a strong oxidizer, has been used widely in the treatment ofwastewater. We prepared Fe2O3/γ-Al2O3 catalyst by impregnation method and characterized it by powder X-ray diffraction （XRD...Heterogeneous Fenton reagent, as a strong oxidizer, has been used widely in the treatment ofwastewater. We prepared Fe2O3/γ-Al2O3 catalyst by impregnation method and characterized it by powder X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）, scanning electron microscopy （SEM）. Test results show that Fe203 crystal was compounded on the γ-Al2O3 carder. We tested and optimized Fe203/γ-Al2O3 /H2O2 and Fe2O3/γ-Al2O3 /H2O2/UV processes to remediate organic material of phenol, using phenol solution with an in. itial concentration of 250 mg/L as a representative of phenolic industrial Wastewater. The preparation conditions were optimized based on performance of Fe2Oa/γ-Al2O3 catalyst and the processes to degrade phenol in aqueous environments. The experimental results showed that the phenol removal perfomance with Fe2O3/γ-Al2O3 /H2O2/UV was more complete than with Fe2O3/γ-Al2O3 /H2O2 and degradation rate of phenol reached 89.4% and 94.7% respectively after reaction for2 h.展开更多
Fenton's reagent was employed to treat the wastewater containing RDX.The effects of FeSO4 concentration,H2O2 concentration,pH value,reaction time,temperature and initial COD of wastewater on residual COD of wastew...Fenton's reagent was employed to treat the wastewater containing RDX.The effects of FeSO4 concentration,H2O2 concentration,pH value,reaction time,temperature and initial COD of wastewater on residual COD of wastewater were investigated.The results show that the optimum FeSO4 concentration and pH are 700 mg/L and 2.5,respectively,and the residual COD of wastewater decreases with the rise in H2O2 concentration,but increases with the rise in temperature.After Fenton's reagent treatment,the initial COD of less than 874 mg/L wastewater can meet effluent standard.Under conditions of 100 mg/L H2O2,437 mg/L initial COD and 15 ℃ temperature,the lowest residual COD is obtained at 83.80 mg/L in 5 min.展开更多
In order to improve the pyrotechnical reagent with potassium perchlorate,composite catalyst of active carbon supporting transition metal oxides （TMO）,Fe2O3 and CuO,were prepared and added into pyrotechnical reagent ...In order to improve the pyrotechnical reagent with potassium perchlorate,composite catalyst of active carbon supporting transition metal oxides （TMO）,Fe2O3 and CuO,were prepared and added into pyrotechnical reagent with potassium perchlorate.Accelerating rate calorimeter （ARC） was used to study the catalysis of pyrotechnical reagent which is consisted of potassium perchlorate and composite catalyst.Composite catalyst of both Fe2O3 and CuO supported by active carbon can catalyze pyrotechnical reagent with potassium perchlorate.Furthermore,it can lower the apparent activation energy and accelerate the reaction with a smaller quantity than that with Fe2O3 and CuO.The maximal reaction rate of pyrotechnical reagent with potassium perchlorate mixed with Fe2O3/active carbon and CuO/active carbon is 8.31 min-1 and 9.13 min-1,which is 1.74 times and 1.91 times of pyrotechnical reagent mixed with no catalyst;time to maximal rate was 18.99 min and 1.96 min respectively,which is lower than pyrotechnical reagent mixed with no catalyst by 86.46% and 98.67% ;the apparent activation energy is 368.10 kJ·mol-1 and 325.29 kJ·mol-1,which is lower than pyrotechnical reagent mixed with no catalyst by 31.89% and 39.81% respectively.展开更多
Based on an extended London-Eyring-Polanyi-Sato （LEPS） potential energy surface （PES）, the Ba q-HF reaction has been studied by the quasi-classical trajectory （QCT） method. The reaction integral cross section as...Based on an extended London-Eyring-Polanyi-Sato （LEPS） potential energy surface （PES）, the Ba q-HF reaction has been studied by the quasi-classical trajectory （QCT） method. The reaction integral cross section as a function of collision energy for the Ba q- HF --＊ BaF q- H reaction is presented and the influence of isotope substitution on the differential cross sections （DCSs） and alignments of the product＇s rotational angular momentum have also been studied. The results suggest that the integral cross sections increase with increasing collision energy, and the vibrational excitation of the reagent has great influence on the DCS. In addition, the product＇s rotational polarization is very strong as a result of heavy-heavy-light （HHL） mass combination, and the distinct effect of isotope substitution on the stereodynamics is also revealed.展开更多
文摘An efficient copper-catalyzed regioselective acyloxy-trifluoromethylation of allenamides using Togni'sⅡreagent as the source of both the trifluoromethyl and acyloxy moieties was developed to create a workable route to CF_(3)-substituted allylic esters.The reaction exhibited good functional group tolerance and high efficiency,affording the products in moderate to good yields.Mechanistic investigations indicated a radical process was likely involved in this transformation.
基金the Northeast Petroleum University Youth Science Foundation (No. 2019QNL-35)Guiding Science and Technology Plan Project of Daqing (No. zd-2021-39)。
文摘The degradation of partially hydrolyzed polyacrylamide(HPAM) found in alkaline/surfactant/polymer flooding sewage was investigated using Fenton-type reagents. Different Fenton reagent treatments for HPAM degradation were compared. The effects of pH, hydrogen peroxide(H_(2)O_(2)), ferrous ion(Fe^(2+)), and tartaric ion(C_(4)H_(4)O_(6)^(2-)) concentrations were studied. The degradation reaction occurred within a wide range of pH(3–9). The HPAM degradation performance of photo-Fenton processes using solar light and UV were compared with that of the Fenton process. The degradation rate was found to be strongly dependent on the H_(2)O_(2)/Fe^(2+)/C_(4)H_(4)O_(6)^(2-)molar ratio. The HPAM degradation efficiency was 90%, and the chemical oxygen demand removal efficiency was 85%. HPAM could be degraded into a compound with a lower molecular weight, but it was difficult to achieve complete mineralization to CO_(2). The presence of intermediate products hindered further oxidation in the Fenton process.
基金supported by the National Natural Science Foundation of China (51974370)the Program of Huxiang Young Talents (2019RS2002)the Innovation and Entrepreneurship Project of Hunan Province, China (Grant No.2018GK5026)。
文摘Lithium ion capacitors(LICs)have been widely used as energy storage devices due to their high energy density and high power density.For LICs,pre-lithiation of negative electrode is necessary.In this work,we employ a bifunctional Li6CoO4(LCO)as cathodic pre-lithiation reagent to improve the electrochemical performance of LICs.The synthesized LCO exhibited high first charge specific capacity of 721 mAh g-1and extremely low initial coulombic efficiency of 3.19%,providing sufficient Li+ for the pre-lithiation of negative electrode in the first charge.Simultaneously,Li6–xCoOy is generated from LCO during the first charge process,which exhibits pseudocapacitive property and contributes to capacity in form of surface capacitance during subsequent cycles,increasing the capacity of capacitive positive electrode.With the appropriate amounts of addition to the positive side in LICs,this bifunctional prelithiation reagent LCO shows significantly improved the electrochemical performance with the energy density of 78.5 Wh kg-1after 300 cycles between 2.0 and 4.2 V at 250 mA g-1.
基金Funded by the Natural Science Foundation of the Education Committee of Heilongjiang Province (No. 12511371)
文摘Heterogeneous Fenton reagent, as a strong oxidizer, has been used widely in the treatment ofwastewater. We prepared Fe2O3/γ-Al2O3 catalyst by impregnation method and characterized it by powder X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）, scanning electron microscopy （SEM）. Test results show that Fe203 crystal was compounded on the γ-Al2O3 carder. We tested and optimized Fe203/γ-Al2O3 /H2O2 and Fe2O3/γ-Al2O3 /H2O2/UV processes to remediate organic material of phenol, using phenol solution with an in. itial concentration of 250 mg/L as a representative of phenolic industrial Wastewater. The preparation conditions were optimized based on performance of Fe2Oa/γ-Al2O3 catalyst and the processes to degrade phenol in aqueous environments. The experimental results showed that the phenol removal perfomance with Fe2O3/γ-Al2O3 /H2O2/UV was more complete than with Fe2O3/γ-Al2O3 /H2O2 and degradation rate of phenol reached 89.4% and 94.7% respectively after reaction for2 h.
基金Sponsored by National Nature Science Foundation of China (20476010)
文摘Fenton's reagent was employed to treat the wastewater containing RDX.The effects of FeSO4 concentration,H2O2 concentration,pH value,reaction time,temperature and initial COD of wastewater on residual COD of wastewater were investigated.The results show that the optimum FeSO4 concentration and pH are 700 mg/L and 2.5,respectively,and the residual COD of wastewater decreases with the rise in H2O2 concentration,but increases with the rise in temperature.After Fenton's reagent treatment,the initial COD of less than 874 mg/L wastewater can meet effluent standard.Under conditions of 100 mg/L H2O2,437 mg/L initial COD and 15 ℃ temperature,the lowest residual COD is obtained at 83.80 mg/L in 5 min.
基金Sponsored by the National Natural Science Foundation of China(50874017)
文摘In order to improve the pyrotechnical reagent with potassium perchlorate,composite catalyst of active carbon supporting transition metal oxides （TMO）,Fe2O3 and CuO,were prepared and added into pyrotechnical reagent with potassium perchlorate.Accelerating rate calorimeter （ARC） was used to study the catalysis of pyrotechnical reagent which is consisted of potassium perchlorate and composite catalyst.Composite catalyst of both Fe2O3 and CuO supported by active carbon can catalyze pyrotechnical reagent with potassium perchlorate.Furthermore,it can lower the apparent activation energy and accelerate the reaction with a smaller quantity than that with Fe2O3 and CuO.The maximal reaction rate of pyrotechnical reagent with potassium perchlorate mixed with Fe2O3/active carbon and CuO/active carbon is 8.31 min-1 and 9.13 min-1,which is 1.74 times and 1.91 times of pyrotechnical reagent mixed with no catalyst;time to maximal rate was 18.99 min and 1.96 min respectively,which is lower than pyrotechnical reagent mixed with no catalyst by 86.46% and 98.67% ;the apparent activation energy is 368.10 kJ·mol-1 and 325.29 kJ·mol-1,which is lower than pyrotechnical reagent mixed with no catalyst by 31.89% and 39.81% respectively.
文摘Based on an extended London-Eyring-Polanyi-Sato （LEPS） potential energy surface （PES）, the Ba q-HF reaction has been studied by the quasi-classical trajectory （QCT） method. The reaction integral cross section as a function of collision energy for the Ba q- HF --＊ BaF q- H reaction is presented and the influence of isotope substitution on the differential cross sections （DCSs） and alignments of the product＇s rotational angular momentum have also been studied. The results suggest that the integral cross sections increase with increasing collision energy, and the vibrational excitation of the reagent has great influence on the DCS. In addition, the product＇s rotational polarization is very strong as a result of heavy-heavy-light （HHL） mass combination, and the distinct effect of isotope substitution on the stereodynamics is also revealed.
