本文以稻壳基多孔炭为载体,采用硼氢化钠为还原剂,制备了非贵金属负载复合材料,即Fe-AC、Co-AC和Ni-AC。采用XRD、SEM、BET和XPS分别表征复合材料的物理化学性质。将复合材料分别制成的复合电极,在1 M KOH的三电极体系中,利用循环伏安...本文以稻壳基多孔炭为载体,采用硼氢化钠为还原剂,制备了非贵金属负载复合材料,即Fe-AC、Co-AC和Ni-AC。采用XRD、SEM、BET和XPS分别表征复合材料的物理化学性质。将复合材料分别制成的复合电极,在1 M KOH的三电极体系中,利用循环伏安、交流阻抗、电化学活性表面积(ECSA)、塔菲尔斜率等方法研究复合电极电催化氧化肼(HzOR)的性能与机理。结果表明,成功地获得了非贵金属包膜多孔炭复合材料,并成功地应用于碱体系的电催化氧化肼中。综合性能推断,其中Co-AC比表面积可达到804.4 m^(2)/g,Co-AC表现出最高的ECSA为49.3 cm^(2),扫速为10 mV/s时反应速率最快,并且能在大于100 mA/cm^(2)的电流密度下保持持续稳定工作,说明具有良好的稳定性。展开更多
Mining activities have created great wealth, but they have also discharged large quantities of tailings. As an important source of heavy metal contamination, sulfide tailings are usually disposed of in open-air impoun...Mining activities have created great wealth, but they have also discharged large quantities of tailings. As an important source of heavy metal contamination, sulfide tailings are usually disposed of in open-air impoundments and thus are exposed to microbial oxidation. Microbial activities greatly enhance sulfide oxidation and result in the release of heavy metals and the precipitation of iron (oxy) hydroxides and sulfates. These secondary minerals in turn influence the mobility of dissolved metals and play important roles in the natural attenuation of heavy metals. Elucidating the microbe–mineral interactions in tailings will improve our understanding of the environmental consequence of mining activities.展开更多
TWC-equipped exhausts are widely used in gasoline-fueled vehicles to meet stringent emission regulations. The main components in TWCs are precious metals such as palladium (Pd), platinum (Pt), and rhodium (Rh) as the ...TWC-equipped exhausts are widely used in gasoline-fueled vehicles to meet stringent emission regulations. The main components in TWCs are precious metals such as palladium (Pd), platinum (Pt), and rhodium (Rh) as the active component, and inorganic oxides such as γ-alumina (Al 2 O 3 ), ceria (CeO 2 ), zirconia (ZrO 2 ) and ceria-zirconia (CeO 2-ZrO 2 ) are used as the support. Interaction of precious metals and support plays an important role in the thermal stability and catalytic performance of TWCs. The support can improve the dispersion of precious metals and suppress the sintering of precious metals at high temperature. In the same, precious metals can also enhance the redox performance and oxygen storage capacity of support. This paper reviews the reaction phenomenon and mechanism of precious metals (Pt, Pd, Rh) and supports such as Al 2 O 3 , CeO 2-based composite oxides.展开更多
文摘Mining activities have created great wealth, but they have also discharged large quantities of tailings. As an important source of heavy metal contamination, sulfide tailings are usually disposed of in open-air impoundments and thus are exposed to microbial oxidation. Microbial activities greatly enhance sulfide oxidation and result in the release of heavy metals and the precipitation of iron (oxy) hydroxides and sulfates. These secondary minerals in turn influence the mobility of dissolved metals and play important roles in the natural attenuation of heavy metals. Elucidating the microbe–mineral interactions in tailings will improve our understanding of the environmental consequence of mining activities.
基金National Science technology Support Plan Projects"(2012BAE06B00)
文摘TWC-equipped exhausts are widely used in gasoline-fueled vehicles to meet stringent emission regulations. The main components in TWCs are precious metals such as palladium (Pd), platinum (Pt), and rhodium (Rh) as the active component, and inorganic oxides such as γ-alumina (Al 2 O 3 ), ceria (CeO 2 ), zirconia (ZrO 2 ) and ceria-zirconia (CeO 2-ZrO 2 ) are used as the support. Interaction of precious metals and support plays an important role in the thermal stability and catalytic performance of TWCs. The support can improve the dispersion of precious metals and suppress the sintering of precious metals at high temperature. In the same, precious metals can also enhance the redox performance and oxygen storage capacity of support. This paper reviews the reaction phenomenon and mechanism of precious metals (Pt, Pd, Rh) and supports such as Al 2 O 3 , CeO 2-based composite oxides.
