To understand how NO2 reacts with sea salt particles in the atmosphere of Mega-cities in coastal zones,the heterogeneous reaction of NO2 on the surface of wet sea salt was investigated with diffuse reflectance infrare...To understand how NO2 reacts with sea salt particles in the atmosphere of Mega-cities in coastal zones,the heterogeneous reaction of NO2 on the surface of wet sea salt was investigated with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatography (IC).Kinetic measurements indicated that nitrate formation on sea salt was second order in NO 2 concentration and reactive uptake coefficients were (5.51 ± 0.19) × 10-7 and 1.26 × 10-6 respectively under 0% and 20% relative humidity (RH) at NO 2 molecular concentration of 1.96 × 1015 mol/cm3.The results showed that liquid water was formed at the site of MgCl2·6H2O,CaCl2·2H2O on the surface of sea salt and made the reaction more sustainable by releasing hydrated water and absorbing water from air even under a low RH (30%).Therefore,pure NaCl particles should not be used to represent sea salt in studies of the heterogeneous reaction with NO2.展开更多
为了研究纳米γFe2O3催化剂选择性催化还原法（SCR）脱硝反应机理,采用微分反应器测量了纳米γFe2O3催化剂上SCR反应的动力学参数,并构建了SCR反应动力学模型.实验数据分析结果表明,NH3,NO和O2的反应级数分别为0,0.78~0.93和0.09~0.11,...为了研究纳米γFe2O3催化剂选择性催化还原法（SCR）脱硝反应机理,采用微分反应器测量了纳米γFe2O3催化剂上SCR反应的动力学参数,并构建了SCR反应动力学模型.实验数据分析结果表明,NH3,NO和O2的反应级数分别为0,0.78~0.93和0.09~0.11,反应活化能为57.3 k J/mol.原位红外漫反射光谱（DRIFTS）实验结果表明：NH3能够强吸附到催化剂表面并达到饱和,进一步增加NH3的浓度并不能增加NO的转化速率;NO在有氧条件下能吸附到催化剂表面生成吸附态NO2和亚硝酸盐;在低于270℃的情况下SCR反应遵循Langmuir-Hinshelw ood（L-H）反应机理,在高于270℃的情况下则主要遵循Eley-Rideal（E-R）反应机理.展开更多
基金supported by the National Natural Science Foundation of China(20637020,40490265 & 20077001)National Basic Research Program of China(2002CB410802)special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control
文摘To understand how NO2 reacts with sea salt particles in the atmosphere of Mega-cities in coastal zones,the heterogeneous reaction of NO2 on the surface of wet sea salt was investigated with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatography (IC).Kinetic measurements indicated that nitrate formation on sea salt was second order in NO 2 concentration and reactive uptake coefficients were (5.51 ± 0.19) × 10-7 and 1.26 × 10-6 respectively under 0% and 20% relative humidity (RH) at NO 2 molecular concentration of 1.96 × 1015 mol/cm3.The results showed that liquid water was formed at the site of MgCl2·6H2O,CaCl2·2H2O on the surface of sea salt and made the reaction more sustainable by releasing hydrated water and absorbing water from air even under a low RH (30%).Therefore,pure NaCl particles should not be used to represent sea salt in studies of the heterogeneous reaction with NO2.
文摘为了研究纳米γFe2O3催化剂选择性催化还原法（SCR）脱硝反应机理,采用微分反应器测量了纳米γFe2O3催化剂上SCR反应的动力学参数,并构建了SCR反应动力学模型.实验数据分析结果表明,NH3,NO和O2的反应级数分别为0,0.78~0.93和0.09~0.11,反应活化能为57.3 k J/mol.原位红外漫反射光谱（DRIFTS）实验结果表明：NH3能够强吸附到催化剂表面并达到饱和,进一步增加NH3的浓度并不能增加NO的转化速率;NO在有氧条件下能吸附到催化剂表面生成吸附态NO2和亚硝酸盐;在低于270℃的情况下SCR反应遵循Langmuir-Hinshelw ood（L-H）反应机理,在高于270℃的情况下则主要遵循Eley-Rideal（E-R）反应机理.
基金National Defense Basic Research Program of China(613142020201)Scientific and Technological Research and Development Foundation of Shenzhen City(JCYJ20140418193546111)
