Bouša Daniel, Friess Karel, Pilnáček Kryštof, Vopička Ondřej, Lanč Marek, Fónod Kristián, Pumera Martin, Sedmidubský David, Luxa Jan, Sofer Zdeněk
Department of Inorganic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Czech Republic.
Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Czech Republic.
Chemistry. 2017 Aug 22;23(47):11416-11422. doi: 10.1002/chem.201702233. Epub 2017 Aug 1.
The preparation and gas-separation performance of self-standing, high-flux, graphene oxide (GO) membranes is reported. Defect-free, 15-20 μm thick, mechanically stable, unsupported GO membranes exhibited outstanding gas-separation performance towards H /CO that far exceeded the corresponding 2008 Robeson upper bound. Remarkable separation efficiency of GO membranes for H and bulky C or C hydrocarbons was achieved with high flux and good selectivity at the same time. On the contrary, N and CH molecules, with larger kinetic diameter and simultaneously lower molecular weight, relative to that of CO , remained far from the corresponding H /N or H /CH upper bounds. Pore size distribution analysis revealed that the most abundant pores in GO material were those with an effective pore diameter of 4 nm; therefore, gas transport is not exclusively governed by size sieving and/or Knudsen diffusion, but in the case of CO was supplemented by specific interactions through 1) hydrogen bonding with carboxyl or hydroxyl functional groups and 2) the quadrupole moment. The self-standing GO membranes presented herein demonstrate a promising route towards the large-scale fabrication of high-flux, hydrogen-selective gas membranes intended for the separation of H /CO or H /alkanes.
报道了自立式、高通量氧化石墨烯（GO）膜的制备及其气体分离性能。无缺陷、厚度为15 - 20μm、机械稳定、无支撑的GO膜对H₂/CO₂表现出优异的气体分离性能，远远超过了相应的2008年罗伯逊上限。GO膜对H₂与大分子C₃或C₄烃类实现了显著的分离效率，同时具有高通量和良好的选择性。相反，相对于CO₂，N₂和CH₄分子具有更大的动力学直径且分子量更低，其分离性能仍远低于相应的H₂/N₂或H₂/CH₄上限。孔径分布分析表明，GO材料中最丰富的孔是有效孔径为4nm的孔；因此，气体传输并非仅由尺寸筛分和/或克努森扩散控制，对于CO₂而言，还通过以下特定相互作用得到补充：1）与羧基或羟基官能团形成氢键；2）四极矩。本文所展示的自立式GO膜为大规模制备用于分离H₂/CO₂或H₂/烷烃的高通量、氢选择性气体膜提供了一条有前景的途径。
