Porous carbon frameworks with high CO2 capture capacity derived from hierarchical polyimide/zeolitic imidazolate frameworks composite aerogels
Porous carbon frameworks with high CO2 capture capacity derived from hierarchical polyimide/zeolitic imidazolate frameworks composite aerogels
复制标题
具有高 CO2 捕获能力的多孔碳框架源自分级聚酰亚胺/沸石咪唑酯框架复合气凝胶
DOI：
10.1016/j.cej.2020.124927
复制
发表时间：
2020
影响因子：
15.1
通讯作者：
Zhang Qinghua
中科院分区：
文献类型：
--
作者：
Wu Tingting;Dong Jie;De France Kevin;Zhang Peiyan;Zhao Xin;Zhang Qinghua
咪唑类沸石骨架材料（ZIF）具有高比表面积和有序的孔道结构，被广泛认为是一种很有前途的CO2捕集和封存材料。然而，ZIF被制造成细粉末，因此将其有效地加工成用于实际应用的功能材料通常具有挑战性。因此，本研究的目的是采用直接混合、超临界CO2干燥和碳化的方法制备一种基于聚酰亚胺/ZIF（PI/ZIF）复合气凝胶的新型多孔炭材料。结果表明，由于聚酰胺酸链上的羧基与金属离子之间的强烈络合作用，有机金属骨架在与聚酰胺酸（PAA）溶液混合时不稳定并会发生坍塌，这对PI/ZIF复合气凝胶的微孔结构有很大影响.因此，所得碳气凝胶显示出复杂的分层多孔结构，可以通过ZIF负载量（高达20wt%）和所使用的ZIF类型来改变。尽管直接加入ZIF后，所制备的PI气凝胶的CO2捕获性能没有显著提高，但随后的碳化导致ZIF浓度高于10重量%时的显著增强，达到50 cm 3/g（2.23 mmol/g，298 K）。总体而言，我们报告了一个直接的生产过程，用于制备分级PI气凝胶，可以进一步增强CO2捕获性能，证明其实际功能的CO2吸附。
Zeolitic imidazolate frameworks (ZIF) are widely regarded as promising materials for CO2capture and storage because of their high specific surface areas and ordered pore structures. However, ZIF are manufactured as a fine powder, and as a result it is often challenging to process them efficiently into functional materials for practical application. Therefore, the objective of this work is to demonstrate a facile direct mixing, supercritical CO2drying, and carbonization process for preparing a novel porous carbon materials based on polyimide/ZIF (PI/ZIF) composite aerogels. An interesting finding is that the organometallic frameworks are unstable and can collapse as mixing with the polyamic acid (PAA) solution due to the strong complexation between carboxyl group in polyamic acid chains and metal ions, which shows a great effect on the microporous structure of PI/ZIF composite aerogels. Accordingly, the resultant carbon aerogels displayed a complex hierarchical porous structure, which can be alteredviaZIF loading amount (up to 20 wt%) and type of ZIF used. Although the CO2capture performance of as-prepared PI aerogels was not significantly improvedviathe direct addition of ZIF, subsequent carbonization resulted in dramatic enhancements at concentrations above 10 wt% of ZIF, reaching up to 50 cm3/g (2.23 mmol/g, 298 K). Overall, we report a direct production process for preparing hierarchical PI aerogels which can be further carbonized for enhanced CO2capture performance, demonstrating their practical functionality for CO2adsorption.