英语翻译3.Results and discussion3.1.Porous texture characterizationIt is remarkable that 25 porous carbons from different precursors and preparation methods are gathered in this study,what offers a variety of porous texture and structure which is
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英语翻译3.Results and discussion3.1.Porous texture characterizationIt is remarkable that 25 porous carbons from different precursors and preparation methods are gathered in this study,what offers a variety of porous texture and structure which is
英语翻译
3.Results and discussion
3.1.Porous texture characterization
It is remarkable that 25 porous carbons from different precursors and preparation methods are gathered in this study,what offers a variety of porous texture and structure which is rarely found in the literature.All the materials prepared have type I isotherms,what is characteristic of microporous solids.Table 3 contains the BET surface areas and the micropore volumes calculated from N2 adsorption data at 77 K [VDR(N2)] and CO2 adsorption data at 273 K [VDR(CO2)] for each sample.It is interesting to note that samples with different adsorption capacity and micropore size distributions have been developed.A more detailed description of the porous texture for each series of materials is included below,which is in agreement with previous results [17–21].
In chemical activation,as a general trend,the adsorption capacity and,consequently,the porosity development,increase with increasing the hydroxide/carbon ratio.Additionally,the knee of the isotherms widens with the increase of the hydroxide/carbon ratio,thus indicating an increase of the micropore size distribution.The differences between KOH and NaOH activations have been shown to be dependent on the structure of the precursor as it has been previously reported [18,19,27].
The comparison between the total micropore volume,VDR(N2),and the narrow micropore volume,VDR(CO2),gives information of the micropore size distribution [22–25].Micropores smaller than 0.7 nm in size are measured by VDR(CO2),and those smaller than 2 nm and bigger than 0.7 nm are calculated by the difference between VDR(N2) and VDR(CO2).In activated samples from anthracite and Donacarbo,low hydroxide/ carbon ratios give VDR(CO2) > VDR(N2) which indicates that very narrow microporosity has been developed.As this ratio increases,the mean pore size is higher.Moreover,it is important to note that Donacarbo samples activated with NaOH develop wider microporosity than those activated with KOH.For Hexcel activated samples,the micropore size distribution is wider in all the cases compared to the other precursors (i.e.,anthracite and Donacarbo).Activated carbon fibres prepared by physical activation with CO2 (Donacarbo samples) and with steam (Kureha samples),are essentially microporous.The micropore size distribution is narrow at low burnoffs and becomes wider with increasing the burnoff.Another remarkable finding is that the micropore size distributions obtained by physical activation are wider than by chemical activation with KOH or NaOH.
In summary,a large number of porous carbons (powder and fibres) were prepared in our laboratory from different precursors and using four activating agents at different experimental conditions,which cover a wide range of porosities and surface areas (from 200 to 3000 m2/g).
英语翻译3.Results and discussion3.1.Porous texture characterizationIt is remarkable that 25 porous carbons from different precursors and preparation methods are gathered in this study,what offers a variety of porous texture and structure which is
3.结果和讨论
3.1.多孔纹理描述特性
It是卓越的从不同的前体和准备方法的25多孔碳在这项研究中被会集,什么提供各种各样在文学很少被找到的多孔纹理和结构.准备的所有材料有类型我等温线,什么是典型的多微孔的固体.表3包含从N2吸附数据和微孔容量计算的赌注表面在77 K [VDR (N2)] 并且二氧化碳在273 K [VDR (二氧化碳)的]吸附数据 为每个样品.注意到是有趣的,用不同的吸附容量和微孔大小分布的样品被开发了.多孔纹理的详细描写材料每系列的下面是包括的,是与早先结果[17–21意见的一致].
In化工活化作用,作为一个一般趋向、吸附容量,并且,因而,多孔性随着氢氧化的增加发展、增量或碳比率.另外,等温线的膝盖随着氢氧化或碳比率的增加加宽,因而表明微孔大小分布的增量.在酸值和NaOH活化作用之间的区别证明是依赖的于前体的结构,当以前报告了[18,19,27].在总微孔容量、VDR (N2)和狭窄的微孔容量,VDR (二氧化碳)之间的The比较,提供微孔大小分布[22–25的]信息.微孔小于0.7毫微米由VDR (二氧化碳)和那些在大小上测量小于2毫微米和大于0.7毫微米由在VDR (N2)和VDR (二氧化碳)之间的区别计算.在从硬煤和Donacarbo的被激活的样品,低氢氧化碳比率给VDR (二氧化碳) >表明的VDR (N2)非常狭窄的微孔性被开发了.当这个比率增加,卑鄙毛孔大小更高.而且,是重要对笔记Donacarbo样品激活与NaOH比那些开发更宽的微孔性激活与酸值.对于Hexcel被激活的样品,微孔大小分布是宽在所有案件与其他前体比较(即,硬煤和Donacarbo).物理活化作用准备的被激活的碳纤维与二氧化碳(Donacarbo样品)和与蒸汽(Kureha样品),本质上是多微孔的.随着熔化的增加,微孔大小分布是狭窄的在低熔化并且更宽成为.另一卓越发现是物理活化作用获得的微孔大小分布由与酸值或NaOH的化工活化作用宽比.总之,很大数量的多孔碳(粉末和纤维)在我们的从不同的前体和使用四种放射化物质的实验室准备了在不同的试验条件,包括各种各样的多孔性和表面(从200到3000 m2/g).