The interaction of mineral oxides （α-A12O3, MgO, Fe2O3, and SiO2） with hydrogen peroxide was investigated using the Knudsen cell reactor. The initial reactive uptake coefficients for tile commercially available pow...The interaction of mineral oxides （α-A12O3, MgO, Fe2O3, and SiO2） with hydrogen peroxide was investigated using the Knudsen cell reactor. The initial reactive uptake coefficients for tile commercially available powders are measured as （1.00±0.11）×10-4 for α-A1203, （1.66±0.23）×10-4 for MgO, （9.70±1.95）×10-5 for Fe203, and （5.22±0.9）×10-5 for SiO2. These metal oxide powders exhibit some catalytic behavior toward the decomposition of hydrogen peroxide excluding SiO2. H2O2 can be destroyed on Fe2O3 surface and O2 is formed. The experimental results suggest that the heterogeneous loss on mineral surface can represent an important sink of hydrogen peroxide.展开更多
The ozonolysis of 2,3,7,8-tetra-chlorodibenzo-p-dioxin （2,3,7,8-TCDD） is an efficient degradation way in the atmosphere. The ozonolysis process and possible reactions path of Criegee Intermediates with NO and H2O ar...The ozonolysis of 2,3,7,8-tetra-chlorodibenzo-p-dioxin （2,3,7,8-TCDD） is an efficient degradation way in the atmosphere. The ozonolysis process and possible reactions path of Criegee Intermediates with NO and H2O are introduced in detail at the method of MPWB1K/6-31＋G（d,p）//MPWB1K/6- 311＋G（3df,2p） level. In ozonolysis, H2O is an important source of OH radical formation and initiated the subsequent degradation reaction. The Rice-Ramsperger-Kassel-Marcus （RRKM） theory was applied to calculate rate constants with the temperature ranging from 200 to 600 K. The rate constant of reaction between 2,3,7,8-TCDD and 03 is 4.80 × 10^-20 cm3/（mole.sec） at 298 K and 760 Tort. The atmospheric lifetime of the reaction species was estimated according to rate constants, which is helpful for the atmospheric model study on the degradation and risk assessment of dioxin.展开更多
Rate constants for the reactions of ozone with 1-octen-3-ol, 1-nonen-3-ol and 1-nonen-4-ol have been determined at 298 ±1 K and atmospheric pressure for the first time. The experiments were performed in a 100-L F...Rate constants for the reactions of ozone with 1-octen-3-ol, 1-nonen-3-ol and 1-nonen-4-ol have been determined at 298 ±1 K and atmospheric pressure for the first time. The experiments were performed in a 100-L FEP Teflon film bag using absolute rate method; the rate constants were （1.91 ± 0.19） ×10^-17, （1.89 ± 0.20） × 10^-17, and （0.83 ± 0.08） × 10^-17 cm^3/（molecule.sec） for 1-octen-3-ol, 1-nonen-3-ol, and 1-nonen-4-ol, respectively. The rate constants have been compared with those of unsaturated alcohols structural homologs, and used to estimate the reaction reactivity. The electronegativity of carbon-carbon double bond was calculated by atomic charges analysis. The calculated results show that the electronic effect of the lone pair electrons of hydroxyl oxygen is the main cause of the difference in rate coefficient. According to the obtained rate constants, the atmospheric lifetimes of studied unsaturated alcohols were also estimated, which indicates that the reaction with ozone is an important loss pathway in the atmosphere, especially in polluted areas.展开更多
基金This work was supported by the Knowledge Innovation Program of the Chinese Academy of Sciences （No.KJCX2-YW-N24, No.KZCX2-YW-Q02-03）the National Basic Research Program of China of Ministry of Science and Technology of China （No.2011CB403401） and the National Natural＇ Science Foundation of China （No.40925016, No.40830101, No.21077109, and No.41005070）.
文摘The interaction of mineral oxides （α-A12O3, MgO, Fe2O3, and SiO2） with hydrogen peroxide was investigated using the Knudsen cell reactor. The initial reactive uptake coefficients for tile commercially available powders are measured as （1.00±0.11）×10-4 for α-A1203, （1.66±0.23）×10-4 for MgO, （9.70±1.95）×10-5 for Fe203, and （5.22±0.9）×10-5 for SiO2. These metal oxide powders exhibit some catalytic behavior toward the decomposition of hydrogen peroxide excluding SiO2. H2O2 can be destroyed on Fe2O3 surface and O2 is formed. The experimental results suggest that the heterogeneous loss on mineral surface can represent an important sink of hydrogen peroxide.
基金supported by National Natural Science Foundation of China(No.21277082,21177076,71201093)the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province(No.BS2012HZ009,BS2012SF012)+2 种基金the Hi-Tech Research and Development Program(863)of China(No.2012AA06A301)the New Century Excellent Talents in University(NCET-13-0349)the Open Project from special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.13K05ESPCP)
文摘The ozonolysis of 2,3,7,8-tetra-chlorodibenzo-p-dioxin （2,3,7,8-TCDD） is an efficient degradation way in the atmosphere. The ozonolysis process and possible reactions path of Criegee Intermediates with NO and H2O are introduced in detail at the method of MPWB1K/6-31＋G（d,p）//MPWB1K/6- 311＋G（3df,2p） level. In ozonolysis, H2O is an important source of OH radical formation and initiated the subsequent degradation reaction. The Rice-Ramsperger-Kassel-Marcus （RRKM） theory was applied to calculate rate constants with the temperature ranging from 200 to 600 K. The rate constant of reaction between 2,3,7,8-TCDD and 03 is 4.80 × 10^-20 cm3/（mole.sec） at 298 K and 760 Tort. The atmospheric lifetime of the reaction species was estimated according to rate constants, which is helpful for the atmospheric model study on the degradation and risk assessment of dioxin.
基金supported by the National Natural Science Foundation of China (Nos. 41571130022, 91544223, 21473009)
文摘Rate constants for the reactions of ozone with 1-octen-3-ol, 1-nonen-3-ol and 1-nonen-4-ol have been determined at 298 ±1 K and atmospheric pressure for the first time. The experiments were performed in a 100-L FEP Teflon film bag using absolute rate method; the rate constants were （1.91 ± 0.19） ×10^-17, （1.89 ± 0.20） × 10^-17, and （0.83 ± 0.08） × 10^-17 cm^3/（molecule.sec） for 1-octen-3-ol, 1-nonen-3-ol, and 1-nonen-4-ol, respectively. The rate constants have been compared with those of unsaturated alcohols structural homologs, and used to estimate the reaction reactivity. The electronegativity of carbon-carbon double bond was calculated by atomic charges analysis. The calculated results show that the electronic effect of the lone pair electrons of hydroxyl oxygen is the main cause of the difference in rate coefficient. According to the obtained rate constants, the atmospheric lifetimes of studied unsaturated alcohols were also estimated, which indicates that the reaction with ozone is an important loss pathway in the atmosphere, especially in polluted areas.
