文献类型：期刊文献

英文题名：Tunable hydrogen separation in sp-sp2 hybridized carbon membranes: A first-principles prediction

作者：Zhang, Hongyu[1]; He, Xiujie[2]; Zhao, Mingwen[2]; Zhang, Meng[1]; Zhao, Lixia[1]; Feng, Xiaojuan[1]; Luo, Youhua[1]

机构：[1] Department of Physics, East China University of Science and Technology, Shanghai 200237, China; [2] School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China

年份：2012

卷号：116

期号：31

起止页码：16634

外文期刊名：Journal of Physical Chemistry C

收录：EI(收录号：20123415353161)

语种：英文

外文关键词：Gas permeable membranes - Separation - Sieves - Carbon - Calculations - Hydrogen - Molecules - Pore size

摘要：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 suggest that the abundant pores of different sizes in these carbon allotropes make them ideal molecular sieves for gas separation applications directed toward different separation needs and objectives. ? 2012 American Chemical Society.