The dependence of the hydrogen sorption capacity of single-walled carbon nanotubes on the concentration of catalyst
The dependence of the hydrogen sorption capacity of single-walled carbon nanotubes on the concentration of catalyst
复制标题
单壁碳纳米管吸氢能力对催化剂浓度的依赖性
DOI：
10.1016/j.carbon.2009.07.030
复制
发表时间：
2009
期刊：
影响因子：
10.9
通讯作者：
Seifi M
中科院分区：
文献类型：
--
作者：
Seifi M
氢在单壁碳纳米管上的吸附是使用微重量氮和氢吸附等温线在77K下测量的，气体压力高达1bar（氮气）和12bar（氢气）。结果表明，表面积和吸氢量取决于用于制造纳米管的铁催化剂的浓度。朗缪尔拟合的氢吸收曲线清楚地显示了两个吸附能为每个样品，我们归因于凹槽网站的较高的吸附能和较低的能量凸管表面。我们还计算了单壁碳纳米管上这些相同位点上氢的结合能，并确认凹槽位点比表面位点具有显着更高的（取决于半径）结合能，与实验值一致。这表明，使用的Langmuir模型是适当的吸附的H2活性炭的温度和压力范围内的调查，并可用于作为一种快速的方法来估计样品中的平均管半径。
The adsorption of hydrogen on single-walled carbon nanotubes was measured using micro-gravimetric nitrogen and hydrogen adsorption isotherms at 77K for gas pressures of up to 1bar (nitrogen) and 12bar (hydrogen). Results show that surface area and hydrogen uptake depend on the concentration of the iron catalyst used for making the nanotubes. Langmuir fits to the hydrogen uptake curves clearly show two adsorption energies for each sample which we attribute to the groove site for the higher adsorption energy and to the convex tube surface for the lower energy. We also present calculations of the binding energy of hydrogen on these same sites on SWCNTs and confirm that the groove site has a significantly higher (radius-dependent) binding energy than the surface site, consistent with the experimental values. This suggests that the use of the Langmuir model is appropriate to the adsorption of H2 on activated carbons for the temperature and pressure range investigated and could be used as a rapid way of estimating the average tube radius in the sample.