We report up to 6 wt% storage of H2 at 2 atm and T = 77 K in processed bundles of single-walled carbon nanotubes. The hydrogen storage isotherms are completely reversible; D2 isotherms confirmed this anomalous low-pressure adsorption and also revealed the effects of quantum mechanical zero point motion. We propose that our postsynthesis treatment of the sample improves access for hydrogen to the central pores within individual nanotubes and may also create a roughened tube surface with an increased binding energy for hydrogen. Such an enhancement may be needed to understand the strong adsorption at low pressure. We obtained an experimental isosteric heat qst = 125 ± 5 meV. Calculations are also presented that indicate disorder in the tube wall enhances the binding energy of H2.
我们报告了在 2 atm 和 T = 77 K 条件下,单壁碳纳米管加工束中高达 6 wt% 的 H2 储量。储氢等温线是完全可逆的;D2 等温线证实了这种反常的低压吸附,同时也揭示了量子力学零点运动的影响。我们认为,我们对样品进行的合成后处理改善了
氢气进入单个纳米管中心孔隙的通道,还可能形成一个粗糙的管表面,增加了
氢气的结合能。要理解低压下的强吸附性,可能需要这种增强。我们获得了实验等位热 qst = 125 ± 5 meV。计算结果还表明,管壁的无序会增强氢的结合能。