Palladium‐Percolated Networks Enabled by Low Loadings of Branched Nanorods for Enhanced H2 Separations
Palladium‐Percolated Networks Enabled by Low Loadings of Branched Nanorods for Enhanced H2 Separations
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通过低负载支化纳米棒实现钯渗透网络以增强 H2 分离
DOI：
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Haiqing Lin
中科院分区：
文献类型：
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作者：
Leiqing Hu;Kaiwen Chen;Wonmoo Lee;K. Kisslinger;C. Rumsey;Shouhong Fan;Vinh Bui;Narjes Esmaeili;Thien N. Tran;Yifu Ding;Martin Trebbin;C. Nam;M. Swihart;Haiqing Lin
高负载量的纳米颗粒（NP）通常用于混合基质膜（MMM）中以改善气体分离性能，但它们可能导致阻碍膜制造的缺陷和差的可加工性。在此，证明了具有受控纵横比的支化纳米棒（NR）可以显著降低所需的负载以实现上级气体分离性能，同时保持优异的可加工性，如钯（Pd）NR在聚苯并咪唑中的分散体用于H2/CO2分离所证明的。将纳米颗粒的纵横比从1增加到NR的40，将逾渗阈值体积分数降低了30倍，从0.35降低到0.011。当在200 °C下用模拟合成气挑战时，具有由体积分数为0.039的Pd NR形成的网状结构的MMM表现出110 Barrer的H2渗透性和31的H2/CO2选择性，超过了Robeson的上限。这项工作突出了NR相对于NP和纳米线的优势，并表明MMM中正确尺寸的纳米填料对于以最小负载构建高度筛分的路径至关重要。这项工作为将这种一般特性应用于各种化学分离的材料系统铺平了道路。
Nanoparticles (NPs) at high loadings are often used in mixed matrix membranes (MMMs) to improve gas separation properties, but they can lead to defects and poor processability that impede membrane fabrication. Herein, it is demonstrated that branched nanorods (NRs) with controlled aspect ratios can significantly reduce the required loading to achieve superior gas separation properties while maintaining excellent processability, as demonstrated by the dispersion of palladium (Pd) NRs in polybenzimidazole for H2/CO2 separation. Increasing the aspect ratio from 1 for NPs to 40 for NRs decreases the percolation threshold volume fraction by a factor of 30, from 0.35 to 0.011. An MMM with percolated networks formed by Pd NRs at a volume fraction of 0.039 exhibits H2 permeability of 110 Barrer and H2/CO2 selectivity of 31 when challenged with simulated syngas at 200 °C, surpassing Robeson's upper bound. This work highlights the advantage of NRs over NPs and nanowires and shows that right‐sizing nanofillers in MMMs is critical to construct highly sieving pathways at minimal loadings. This work paves the way for this general feature to be applied across materials systems for a variety of chemical separations.