Methyl iodide(CH3I)is an important trace greenhouse gas in the atmosphere and an ozone-depleting substance.The influence of different environmental factors,such as the duration of illumination;the strength of illumina...Methyl iodide(CH3I)is an important trace greenhouse gas in the atmosphere and an ozone-depleting substance.The influence of different environmental factors,such as the duration of illumination;the strength of illumination;the concentrations of humic acid,ferric ion(Fe^3+),and iodide ion(I−);and pH,on the photochemical production of CH3I in artificial seawater(ASW)were tested by simulated solar irradiation.In addition,Yangtze River Estuary waters from inshore to offshore were used to explore the relationship between the photochemical production of CH3I and different sources of dissolved organic matter(DOM)in natural seawater(NSW).The results revealed that higher concentrations of humic acid and I−,as well as higher strengths of illumination and longer illumination durations,promoted the photochemical formation of CH3I in ASW.The addition of Fe^3+accelerated the photochemical production of CH3I,but high concentrations of Fe^3+inhibited the formation of CH3I.Experiments on NSW obtained from the Yangtze River estuary spiked when concentrations of DOM were high,confirming that DOM plays an important role in facilitating the photochemical production of CH3I within the Yangtze River Estuary.The photochemical production of CH3I in the seawater was significantly higher under light conditions relative to dark conditions,indicating that illumination accelerated the production of CH3I.展开更多
The detection of the microwave-discharged species of methyl iodide by HeI photoelectron spectroscopy(UPS)is reported for the first time.The UPS spectra of I_2 and HI molecules clearly appeared in the spectrum of micro...The detection of the microwave-discharged species of methyl iodide by HeI photoelectron spectroscopy(UPS)is reported for the first time.The UPS spectra of I_2 and HI molecules clearly appeared in the spectrum of microwave-discharged species of methyl iodide,The mechanism of the change of methyl iodide under microwave discharge was proposed,The result provides the basis for understanding depletion of the ozone shell of the atomsphere by halogenated methane.展开更多
The synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide using potassium hydroxide as catalyst in the presence of CH3I and the effect of ionic liquid on the reaction were investigated. The results ...The synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide using potassium hydroxide as catalyst in the presence of CH3I and the effect of ionic liquid on the reaction were investigated. The results showed that KOH is an effective catalyst; the high selectivity and raised yield of DMC formation under mild conditions were achieved. However, the addition of the ionic liquid, l-ethyl-3-methylimidazolium bromide （emimBr）, can evidently accelerate the conversion of methanol and yield of the product.展开更多
Hydrophobic zeolites have been identified as suitable adsorbents for capturing radioactive iodine species from nuclear-powerplant off-gas because of their high stability and strong water resistance.However,only the mo...Hydrophobic zeolites have been identified as suitable adsorbents for capturing radioactive iodine species from nuclear-powerplant off-gas because of their high stability and strong water resistance.However,only the most common zeolites have been investigated for the capture of molecular iodine to date.Herein,we demonstrate that the composition and pore structure of zeolites considerably affect their iodine adsorption performance.A novel all-silica ExxonMobil material-17(EMM-17)zeolite having a unique three-dimensional 10(12)×10(12)×11-ring channel system exhibits a high adsorption capacity for iodine and methyl iodide in the presence of water.EMM-17 outperforms previously reported zeolites in terms of gravimetric and volumetric adsorption capacity in dynamic adsorption measurements.The excellent iodine/methyl iodide capture properties are attributed to the combination of optimal pore size,high pore volume,strong hydrophobicity,suitable particle morphology.This study provides useful insights for designing efficient adsorbents for iodine capture.展开更多
基金This work was supported by the National Key Research and Development Program(No.2016YFA0601304)the National Natural Science Foundation of China(Nos.41830534,41506088).
文摘Methyl iodide(CH3I)is an important trace greenhouse gas in the atmosphere and an ozone-depleting substance.The influence of different environmental factors,such as the duration of illumination;the strength of illumination;the concentrations of humic acid,ferric ion(Fe^3+),and iodide ion(I−);and pH,on the photochemical production of CH3I in artificial seawater(ASW)were tested by simulated solar irradiation.In addition,Yangtze River Estuary waters from inshore to offshore were used to explore the relationship between the photochemical production of CH3I and different sources of dissolved organic matter(DOM)in natural seawater(NSW).The results revealed that higher concentrations of humic acid and I−,as well as higher strengths of illumination and longer illumination durations,promoted the photochemical formation of CH3I in ASW.The addition of Fe^3+accelerated the photochemical production of CH3I,but high concentrations of Fe^3+inhibited the formation of CH3I.Experiments on NSW obtained from the Yangtze River estuary spiked when concentrations of DOM were high,confirming that DOM plays an important role in facilitating the photochemical production of CH3I within the Yangtze River Estuary.The photochemical production of CH3I in the seawater was significantly higher under light conditions relative to dark conditions,indicating that illumination accelerated the production of CH3I.
文摘The detection of the microwave-discharged species of methyl iodide by HeI photoelectron spectroscopy(UPS)is reported for the first time.The UPS spectra of I_2 and HI molecules clearly appeared in the spectrum of microwave-discharged species of methyl iodide,The mechanism of the change of methyl iodide under microwave discharge was proposed,The result provides the basis for understanding depletion of the ozone shell of the atomsphere by halogenated methane.
文摘The synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide using potassium hydroxide as catalyst in the presence of CH3I and the effect of ionic liquid on the reaction were investigated. The results showed that KOH is an effective catalyst; the high selectivity and raised yield of DMC formation under mild conditions were achieved. However, the addition of the ionic liquid, l-ethyl-3-methylimidazolium bromide （emimBr）, can evidently accelerate the conversion of methanol and yield of the product.
基金the AMPM CCF fund(No.FCC/1/1972-43-01)to Y.H.from King Abdullah University of Science and Technology.
文摘Hydrophobic zeolites have been identified as suitable adsorbents for capturing radioactive iodine species from nuclear-powerplant off-gas because of their high stability and strong water resistance.However,only the most common zeolites have been investigated for the capture of molecular iodine to date.Herein,we demonstrate that the composition and pore structure of zeolites considerably affect their iodine adsorption performance.A novel all-silica ExxonMobil material-17(EMM-17)zeolite having a unique three-dimensional 10(12)×10(12)×11-ring channel system exhibits a high adsorption capacity for iodine and methyl iodide in the presence of water.EMM-17 outperforms previously reported zeolites in terms of gravimetric and volumetric adsorption capacity in dynamic adsorption measurements.The excellent iodine/methyl iodide capture properties are attributed to the combination of optimal pore size,high pore volume,strong hydrophobicity,suitable particle morphology.This study provides useful insights for designing efficient adsorbents for iodine capture.
