Zhu Shan, Li Jiajie, Toth Allison, Landskron Kai
Department of Chemistry , Lehigh University , 6 East Packer Avenue , Bethlehem , Pennsylvania 18015 , United States.
ACS Appl Mater Interfaces. 2019 Jun 19;11(24):21489-21495. doi: 10.1021/acsami.9b03598. Epub 2019 Jun 7.
We quantitatively investigate the influence of the NaCl electrolyte concentration on the adsorptive and energetic characteristics of supercapacitive swing adsorption (SSA) for the separation of CO from a simulated flue gas mixture containing 15% CO and 85% N. The investigated concentrations were that of deionized water, 0.010, 0.10, 1.0, 3.0, and 5.0 M NaCl. We find that the energetic metrics strongly improve with the increasing NaCl concentration, whereas the adsorptive metrics improve by a comparatively small degree. The CO adsorption capacity increases up to 1.0 M NaCl and then remains constant. The adsorption rate remains near constant for all concentrations, except that it is somewhat smaller for deionized water. The charge efficiency also remains near constant for all experiments with 30 min potentiostatic holding steps but near doubles for pure water when the potential holding step is doubled, because the chemical adsorption equilibrium is reached only after 60 min. The results can be most satisfactorily explained by assuming that both ionic and nonionic adsorption mechanisms contribute to the SSA effect.
我们定量研究了NaCl电解质浓度对超级电容变温吸附（SSA）从含有15%CO和85%N₂的模拟烟道气混合物中分离CO的吸附和能量特性的影响。所研究的浓度为去离子水、0.010、0.10、1.0、3.0和5.0 M的NaCl。我们发现，随着NaCl浓度的增加，能量指标显著改善，而吸附指标改善程度相对较小。CO吸附容量在NaCl浓度达到1.0 M之前增加，之后保持恒定。除了去离子水的吸附速率稍小外，所有浓度下的吸附速率都接近恒定。在所有进行30分钟恒电位保持步骤的实验中，电荷效率也接近恒定，但当电位保持步骤加倍时，纯水的电荷效率几乎翻倍，因为化学吸附平衡仅在60分钟后才达到。假设离子和非离子吸附机制都对SSA效应有贡献，那么这些结果可以得到最令人满意的解释。
