Sulfur hexafluoride(SF6)is known as one of the most powerful greenhouse gases in the atmosphere.Reductive photodegradation of SF6 by styrene has been studied with the purpose of developing a novel remediation for sulf...Sulfur hexafluoride(SF6)is known as one of the most powerful greenhouse gases in the atmosphere.Reductive photodegradation of SF6 by styrene has been studied with the purpose of developing a novel remediation for sulfur hexafluoride pollution.Effects of reaction conditions on the destruction and removal efficiency(DRE)of SF6 are examined in this study.Both initial styrene-to-SF6 ratio and initial oxygen concentration exert a significant influence on DRE.SF6 removal efficiency reaches a maximum value at the initial styrene-to-SF6 ratio of 0.2.It is found that DRE increases with oxygen concentration over the range of 0 to 0.09 mol/m^3 and then decreases with increasing oxygen concentration.When water vapor is fed into the gas mixture,DRE is slightly enhanced over the whole studied time scale.The X-ray Photoelectron Spectroscopy(XPS)analysis,together with gas chromatography-mass spectrometry(GC-MS)and Fourier Transform Infrared spectroscopy(FT-IR)analysis,prove that nearly all the initial fluorine residing in the gas phase is in the form of SiF4,whereas,the initial sulfur is deposited in the form of elemental sulfur,after photodegradation.Free from toxic byproducts,photodegradation in the presence of styrene may serve as a promising technique for SF6 abatement.展开更多
The laser flash photolysis technique is em- ployed to investigate the reaction mechanism of CS2 with ·OH in the nitrogen-saturated aqueous solution. By comparison of the transient absorption spectra obtained at d...The laser flash photolysis technique is em- ployed to investigate the reaction mechanism of CS2 with ·OH in the nitrogen-saturated aqueous solution. By comparison of the transient absorption spectra obtained at different phases and pHs and through the addition of proper radical cation scavenger, CS2 is determined to react with ·OH to form ·CS2OH adduct, instead of the CS2+ radical cation. At pH 1―5, ·CS2OH decomposes into COS and ·HS, while at pH>5, it further reacts with OH- to form CS2O-. The tem- perature dependent kinetics for the reaction CS2 + ·OH → ·CS2OH is also reported in this paper with an estimated activation energy of (26.9±1.0) kJ·mol?1.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.20177004,20507004).
文摘Sulfur hexafluoride(SF6)is known as one of the most powerful greenhouse gases in the atmosphere.Reductive photodegradation of SF6 by styrene has been studied with the purpose of developing a novel remediation for sulfur hexafluoride pollution.Effects of reaction conditions on the destruction and removal efficiency(DRE)of SF6 are examined in this study.Both initial styrene-to-SF6 ratio and initial oxygen concentration exert a significant influence on DRE.SF6 removal efficiency reaches a maximum value at the initial styrene-to-SF6 ratio of 0.2.It is found that DRE increases with oxygen concentration over the range of 0 to 0.09 mol/m^3 and then decreases with increasing oxygen concentration.When water vapor is fed into the gas mixture,DRE is slightly enhanced over the whole studied time scale.The X-ray Photoelectron Spectroscopy(XPS)analysis,together with gas chromatography-mass spectrometry(GC-MS)and Fourier Transform Infrared spectroscopy(FT-IR)analysis,prove that nearly all the initial fluorine residing in the gas phase is in the form of SiF4,whereas,the initial sulfur is deposited in the form of elemental sulfur,after photodegradation.Free from toxic byproducts,photodegradation in the presence of styrene may serve as a promising technique for SF6 abatement.
基金supported by the National Natural Science Foundation of China(Grant No.29877005).
文摘The laser flash photolysis technique is em- ployed to investigate the reaction mechanism of CS2 with ·OH in the nitrogen-saturated aqueous solution. By comparison of the transient absorption spectra obtained at different phases and pHs and through the addition of proper radical cation scavenger, CS2 is determined to react with ·OH to form ·CS2OH adduct, instead of the CS2+ radical cation. At pH 1―5, ·CS2OH decomposes into COS and ·HS, while at pH>5, it further reacts with OH- to form CS2O-. The tem- perature dependent kinetics for the reaction CS2 + ·OH → ·CS2OH is also reported in this paper with an estimated activation energy of (26.9±1.0) kJ·mol?1.
