A series of transition metal Mn,Cu,Ce and Fe were loaded on TiO_(2) by sol-gel method with noble metal Pd as promotor for the application of passive NO_(x) absorber.Experiments on adsorption and desorption of NO_(x) w...A series of transition metal Mn,Cu,Ce and Fe were loaded on TiO_(2) by sol-gel method with noble metal Pd as promotor for the application of passive NO_(x) absorber.Experiments on adsorption and desorption of NO_(x) were conducted and characterization methods such as X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM)and in situ Fourier transform infrared spectroscopy(in situ DRIFTS)were involved.The experimental results show that Mn-contained catalysts,Mn-Ti and Pd-Mn-Ti,performed excellent NO_(x) adsorbing ability and appropriate desorption temperature window.On the other hand,Ce-and Cu-contained samples were not suitable for the purpose of PNA.In addition to the low adsorption capacity,these two series of catalysts released massive amount of NO below 150℃.Characterization results indicated that Pd was highly dispersed on all catalysts.The loading of Pd lowered not only the valence states of transition metals but surface oxygen percentage as well.From in situ DRIFTS tests,the Pd had little influence on the types of adsorbed substances for Mn,Ce and Cu series.However,the storage forms of NO_(x) were obviously different on Pd-Fe-Ti and Fe-Ti.展开更多
The research aimed to analyze the linkage between natural vegetation, water dynamics and pyrite （FeS2） oxidation in tidal lowlands. The research was carried out in tidal lowland Pulau Rimau, South Sumatra from Febru...The research aimed to analyze the linkage between natural vegetation, water dynamics and pyrite （FeS2） oxidation in tidal lowlands. The research was carried out in tidal lowland Pulau Rimau, South Sumatra from February to December 2010. The field observations are done by exploring several transect on land units. The field description refers to Soil Survey Staff. Water and soil samples were taken from selected key areas for laboratory analyses. The vegetation data were collected by making sample plots placed on each vegetation type with plot sizes 10 m × 10 m for secondary forests and 5 m × 5 m for shrubs and grass. The observations of surface water level were done during the river receding with units of meter above sea level （m.asl）. The results shows that pyrite formation is largely determined by the availability of natural vegetation as S （sulfur） donors, climate and uncontrolled water balance and supporting faunas such as crabs and mud shrimp. Climate and water balance as well as supporting faunas is the main supporting factors to accelerate the process of formation pyrite. Oxidized pyrite increases soil pH thus toxic to fish, arable soils, plant growth, disturbing the water quality and soil nutrient availability. Oxidized pyrite is predominantly accelerated by the dynamics of river water and disturbed natural vegetation by human activities, and the pyrite oxidation management approach is divided into three main components of technologies, namely water management, land management and commodity management.展开更多
基金Project(52106173)supported by the National Natural Science Foundation of ChinaProject(2020TQ0187)supported by the Postdoctoral Research Foundation of China。
文摘A series of transition metal Mn,Cu,Ce and Fe were loaded on TiO_(2) by sol-gel method with noble metal Pd as promotor for the application of passive NO_(x) absorber.Experiments on adsorption and desorption of NO_(x) were conducted and characterization methods such as X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM)and in situ Fourier transform infrared spectroscopy(in situ DRIFTS)were involved.The experimental results show that Mn-contained catalysts,Mn-Ti and Pd-Mn-Ti,performed excellent NO_(x) adsorbing ability and appropriate desorption temperature window.On the other hand,Ce-and Cu-contained samples were not suitable for the purpose of PNA.In addition to the low adsorption capacity,these two series of catalysts released massive amount of NO below 150℃.Characterization results indicated that Pd was highly dispersed on all catalysts.The loading of Pd lowered not only the valence states of transition metals but surface oxygen percentage as well.From in situ DRIFTS tests,the Pd had little influence on the types of adsorbed substances for Mn,Ce and Cu series.However,the storage forms of NO_(x) were obviously different on Pd-Fe-Ti and Fe-Ti.
文摘The research aimed to analyze the linkage between natural vegetation, water dynamics and pyrite （FeS2） oxidation in tidal lowlands. The research was carried out in tidal lowland Pulau Rimau, South Sumatra from February to December 2010. The field observations are done by exploring several transect on land units. The field description refers to Soil Survey Staff. Water and soil samples were taken from selected key areas for laboratory analyses. The vegetation data were collected by making sample plots placed on each vegetation type with plot sizes 10 m × 10 m for secondary forests and 5 m × 5 m for shrubs and grass. The observations of surface water level were done during the river receding with units of meter above sea level （m.asl）. The results shows that pyrite formation is largely determined by the availability of natural vegetation as S （sulfur） donors, climate and uncontrolled water balance and supporting faunas such as crabs and mud shrimp. Climate and water balance as well as supporting faunas is the main supporting factors to accelerate the process of formation pyrite. Oxidized pyrite increases soil pH thus toxic to fish, arable soils, plant growth, disturbing the water quality and soil nutrient availability. Oxidized pyrite is predominantly accelerated by the dynamics of river water and disturbed natural vegetation by human activities, and the pyrite oxidation management approach is divided into three main components of technologies, namely water management, land management and commodity management.
