排序方式: 共有30条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
以过渡金属盐Co(NO3)2、Mn(NO3)2为钴源、锰源,Al(NO3)3为铝源,NaOH和Na2CO3混合溶液为碱性介质,利用共沉淀法分别制备了n(Co)∶n(Mn)∶n(Al)=4∶0∶2、4∶1∶1、4∶2∶0的CO32-离子插层纳米层状双金属氢氧化物(LDHs)。利用X射线衍射(XRD)、X射线荧光光谱分析(XRF)、N2吸附脱附、透射电镜(TEM)技术对样品进行了表征。结果表明,样品呈层状片状,随着LDHs样品中Mn、Al原子比的增加,结晶度变差,形貌变得无序,平均孔径减小,比表面积和孔道容量变大。 相似文献
5.
采用共沉淀法制备了n(Co)∶n(Mn)∶n(Al)=4∶0∶2、4∶1∶1、4∶2∶0的CO32-离子插层层状双金属氢氧化物(LDHs),经500℃煅烧4h得到相应的Co-Mn-Al复合过渡金属氧化物。利用X射线衍射(XRD)、X射线荧光光谱分析(XRF)、N2吸附脱附、透射电镜(TEM)技术对样品进行了表征。研究结果表明,Co-Mn-Al复合氧化物具有含Co尖晶石氧化物的结构特征,属于中孔材料,与Co-Mn-Al LDHs相比,其比表面积增大,孔容增加,孔径尺寸变小,且随着Mn与Al原子比的增加,样品结晶度及有序性均下降。 相似文献
6.
7.
Catalytic ozonation with coal-based activated carbon ( carbozone) followed by GAC ( granular activated carbon) filtration was compared with ozone-GAC process for water purification. Songhua River water pretreated with traditional processes was used as influent in the continuous-flow experiments. The carbozone-GAC process performed better than the ozone-GAC process during the 9. 5-months operation period. The organic removal rate in carbozone was found to be very high in the initial operation period,and then gradually decreased to a steady level. At the steady state of operation,the average removal rates of permanganate index ( PI) and UV254 were 25. 8% and 67. 8% in carbozone,and 6. 6% and 53. 7% in ozonation alone,respectively. The carbozone process also achieved a higher DOC removal than ozonation alone,and moreover,the number of semi-volatile organic compounds detected with GC/MS decreased from 44 to 28 in carbozone and 34 in ozonation alone,respectively. The catalyst surface became more acidic during the long-term operation with its pHPZC( pH at which its surface is zero charged) decreased from 7. 0 to 6. 2. In addition,the physical characteristics of the catalyst were also changed during the operation. 相似文献
8.
9.
10.
吸附在多相催化臭氧氧化降解有机物中的作用 总被引:3,自引:0,他引:3
采用连续流扣半连续流的运行方式,通过考察在催化剂表面的吸附能力有差异的两种有机污染物——硝基苯与水合三氯乙醛的催化臭氧氧化降解效能,对多相催化臭氧氧化工艺中催化剂的吸附作用进行了讨论。试验结果表明,在多相催化臭氧氧化系统中,对有机物的催化臭氧氧化效能并非是臭氧氧化和催化剂吸附作用的简单叠加,有机物吸附到催化剂表面后会继续被催化氧化分解。催化剂对有机污染物的吸附作用并不是其发挥高效催化能力的必要条件。臭氧在催化剂表面的吸附、分解是催化臭氧氧化系统发挥其效能的关键,所生成活性物质的氧化能力决定了体系对有机物降解效率的高低。 相似文献