Rahimi Mahshid, Babu Deepu J, Singh Jayant K, Yang Yong-Biao, Schneider Jörg J, Müller-Plathe Florian
Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 4, D-64287 Darmstadt, Germany.
J Chem Phys. 2015 Sep 28;143(12):124701. doi: 10.1063/1.4929609.
Grand-canonical Monte Carlo simulations and adsorption experiments are combined to find the optimized carbon nanotube (CNT) arrays for gas adsorption at low pressures and 303 K. Bundles of 3D aligned double-walled carbon nanotube (DWCNT) with inner diameter of 8 nm and different intertube distances were made experimentally. The experimental results show that decreasing intertube distance leads to a significant enhancement in carbon-dioxide (CO2) adsorption capacity at 1 bar. The molecular simulation study on CO2 adsorption onto bundles of 3D aligned DWCNT with inner diameters of 1, 3, and 8 nm and intertube distance of 0-15 nm shows that the intertube distance plays a more important role than the CNT diameter. The simulation results show that decreasing the intertube distance up to 1 nm increases the excess adsorption generally in all the studied systems at pressures 0 < p < 14 bars (the increase can be up to ∼40% depending on the system and pressure). This is in agreement with the experimental result. Further reduction in intertube distance leads to a decrease in the excess adsorption in the pressure range 9 < p < 14 bars. However, at lower pressure, 0 < p < 9 bars, intertube distance of 0.5 nm is found to have the highest excess adsorption. This result is indifferent to tube diameter. Furthermore, molecular simulations are conducted to obtain the optimal parameters, for the DWCNT bundle, for SO2 adsorption, which are similar to those observed for CO2 in the pressure range 0 < p < 3 bars.
结合巨正则蒙特卡罗模拟和吸附实验，以找到在低压和303K下用于气体吸附的优化碳纳米管（CNT）阵列。通过实验制备了内径为8nm且管间距不同的三维排列双壁碳纳米管（DWCNT）束。实验结果表明，减小管间距会导致在1巴压力下二氧化碳（CO₂）吸附容量显著提高。对内径为1、3和8nm且管间距为0 - 15nm的三维排列DWCNT束上CO₂吸附的分子模拟研究表明，管间距比CNT直径起更重要的作用。模拟结果表明，在0 < p < 14巴的压力下，在所有研究的系统中，将管间距减小至1nm通常会增加过量吸附（根据系统和压力，增加量可达约40%）。这与实验结果一致。在9 < p < 14巴的压力范围内，进一步减小管间距会导致过量吸附减少。然而，在较低压力下，0 < p < 9巴，发现管间距为0.5nm时具有最高的过量吸附。该结果与管径无关。此外，进行分子模拟以获得DWCNT束对SO₂吸附的最佳参数，这些参数与在0 < p < 3巴压力范围内观察到的CO₂的参数相似。
