Tunable Hydrogen Separation in sp–sp2 Hybridized Carbon Membranes: A First-Principles Prediction
Tunable Hydrogen Separation in sp–sp2 Hybridized Carbon Membranes: A First-Principles Prediction
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DOI：
10.1021/jp304908p
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发表时间：
2012-07
影响因子：
3.7
通讯作者：
Hongyu Zhang;Xiu-Jie He;Mingwen Zhao;Meng Zhang;Li-xia Zhao;Xiaojuan Feng;You-hua Luo
中科院分区：
文献类型：
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作者：
Hongyu Zhang;Xiu-Jie He;Mingwen Zhao;Meng Zhang;Li-xia Zhao;Xiaojuan Feng;You-hua Luo
通过第一性原理计算，研究了由 sp 和 sp2 杂化碳原子组成的二维碳同素异形体，即石墨炔、石墨二炔和菱形石墨烯的氢分离特性。研究发现，H2 对多种气体分子（包括 CO、N2 和 CH4）的选择性对孔径和形状敏感。渗透屏障通常随孔径大小呈指数下降。我们的结果表明，小孔石墨炔不适合氢分离的目的。石墨炔具有较大的孔隙，相对于 CH4 等大分子气体，对氢气表现出较高的选择性 (109)，但相对于 CO 和 N2 等小分子，其选择性 (103) 相对较低。菱形石墨烯单层的孔径介于石墨炔和石墨二炔之间，分子渗透的扩散势垒存在巨大差异，导致氢与其他石墨烯单层的分离具有高选择性（>1016）。结果...
First-principles calculations are carried out to investigate the hydrogen separation characteristics of two-dimensional carbon allotropes consisting of sp- and sp2-hybridized carbon atoms, i.e., graphyne, graphdiyne, and rhombic-graphyne. The selectivities for H2 over several gas molecules, including CO, N2, and CH4, are found to be sensitive to the pore sizes and shapes. The penetration barriers generally decrease exponentially with the pore sizes. Our results reveal that graphyne with small pores is unsuitable for the purpose of hydrogen separation. Graphdiyne, with larger pores, exhibits a high selectivity (109) for hydrogen over large gas molecules such as CH4, but a relatively low selectivity (103) over small molecules such as CO and N2. The large differences in diffusion barriers for molecules penetration through a rhombic-graphyne monolayer, which possesses pore size in between that of graphyne and graphdiyne, lead to a high selectivity (>1016) for hydrogen separation from the others. The results s...