High-performance carbon molecular sieve membrane for C2H4/C2H6 separation: Molecular insight into the structure-property relationships
High-performance carbon molecular sieve membrane for C2H4/C2H6 separation: Molecular insight into the structure-property relationships
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DOI：
10.1016/j.carbon.2022.08.088
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发表时间：
2022-09
期刊：
影响因子：
10.9
通讯作者：
R. Xu;Mengjie Hou;Yue Wang;Lin Li;Zonglin Pan;Chengwen Song;Tonghua Wang
中科院分区：
文献类型：
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作者：
R. Xu;Mengjie Hou;Yue Wang;Lin Li;Zonglin Pan;Chengwen Song;Tonghua Wang
碳分子筛（CMS）膜由于其独特的狭缝状孔结构，在C2 H4/C2 H6的高效节能分离中显示出诱人的潜力。本工作以新型的聚芳醚酮（PEK-C）为前驱体，制备了用于C2 H4/C2 H6分离的高性能CMS膜。采用分子模拟和深入表征相结合的方法，研究了不同杂化碳原子比例对碳层堆积形态、孔结构和C2 H4/C2 H6扩散分离性能的影响.结果表明，碳层中杂化碳原子数超过3的碳层形成了疏松无序的碳结构和大孔容、大孔径的孔结构（空间空隙），导致CMS膜的C2 H4/C2 H6选择透过性较低。随着sp3/sp2杂化碳比的降低，形成了致密的、具有二维狭缝状超微孔结构的类石墨碳结构，C2 H4/C2 H6选择性明显提高。以PEK-C为前驱体制备的CMS膜具有较高的C2 H4渗透性和上级C2 H4/C2 H6选择性，超过了聚合物膜和CMS膜的折衷界限，在C2 H4/C2 H6分离的工业应用中显示出巨大的潜力。
Carbon molecular sieve (CMS) membranes show attractive potential for energy-efficient separation of C2H4/C2H6due to their unique slit-like pore structure. In this work, a novel precursor polymer of phenolphthalein-based poly(arylene ether ketone) (PEK-C) was introduced to prepare high-performance CMS membranes for C2H4/C2H6separation. Molecular insight into the effect of thesp3/sp2hybridized carbon ratio on the packing morphology of carbon layers, pore size and configuration, and C2H4/C2H6diffusion and separation properties of CMS membranes was investigated via using in-depth characterization techniques combined with molecular simulations. Results show that the carbon layers with moresp3hybridized carbons lead to forming a loose and disordered carbon structure and pore structure with large pore volume and micropore size (steric voids), resulting in low C2H4/C2H6permselectivity of CMS membrane. With the reduction of thesp3/sp2hybridized carbon ratio, a compact and graphite-like carbon structure with the two-dimensional slit-like ultramicropore structure is formed, and the C2H4/C2H6permselectivity is obviously enhanced. The CMS membranes derived from the novel precursor of PEK-C exhibit high C2H4permeability with superior C2H4/C2H6selectivity, which have surpassed the trade-off bounds of both polymeric membrane and CMS membrane, and reveal a great potential in the industrial applications of C2H4/C2H6separation.