Enhanced selective CO2 adsorption on polyamine/MIL-101(Cr) composites
Enhanced selective CO2 adsorption on polyamine/MIL-101(Cr) composites
复制标题
增强聚胺/MIL-101(Cr) 复合材料上的选择性 CO2 吸附
DOI：
10.1039/c4ta01174k
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发表时间：
2014-01-01
影响因子：
11.9
通讯作者：
Chen, Liang
中科院分区：
文献类型：
--
作者：
Lin, Yichao;Lin, Hao;Chen, Liang
温室气体引起的全球气候变化促使人们积极研究如何制定有效的战略来减缓CO2的排放。在本研究中，我们制备了一系列的多胺/金属有机框架（MOF）复合材料作为高选择性的CO2吸附剂从CO2/N-2的混合物，这是相关的烟气中的CO2捕获。我们发现，负载到MIL 101（铬）框架聚乙烯亚胺（PEI）可以显着提高在低压和室温下的选择性CO2吸附容量。此外，比较研究表明，MOF的粒径和PEI的分子量对CO2捕获能力都起着重要作用。关于粒度，较小的MIL-101（Cr）颗粒可以促进PEI加载到内孔中并导致较低的表面积/孔体积。因此，所得PEI/MIL-101（Cr）复合材料具有较低的CO2吸附容量，但通过CO2相对于N-2的较高选择性来补偿。另一方面，低分子量的线性PEI可以很容易地扩散到内孔中，并有效地阻止N-2吸附。因此，本工作中制备的A-PEI-300样品在0.15 bar和25 ℃下表现出3.6 mmol g（-1）的优异CO2吸收率和100% CO2/N-2选择性。相比之下，较高分子量的支化PEI在升高的温度下是有利的，因为由于大量的伯胺基团，复合材料可以保持高的CO2吸附能力。总体而言，聚胺/MOF复合材料被证明是从烟道气中捕获CO2的良好候选吸附剂。为了实现最佳的CO2捕集能力，应该进行多胺和MOF结构的综合优化。
The global climate change induced by greenhouse gases has stimulated active research for developing efficient strategies to mitigate CO2 emission. In the present study, we prepared a series of polyamine/ metal-organic framework (MOF) composites as highly selective CO2 adsorbents from a CO2/N-2 mixture, which is relevant to CO2 capture in flue gas. We show that loading polyethyleneimine (PEI) into MIL101( Cr) frameworks can significantly enhance the selective CO2 adsorption capacity at low pressure and ambient temperature. Further, the comparative study reveals that both the particle size of the MOF and the molecular-weight of PEI play an important role in the CO2 capture ability. Regarding the particle size, smaller MIL-101(Cr) particles can facilitate the loading of PEI into the inner pores and result in lower surface area/pore volume. Thus, the resulting PEI/MIL-101(Cr) composites possess lower CO2 adsorption capacity, but are compensated by higher selectivity of CO2 over N-2. On the other hand, lower molecular-weight linear PEI could readily diffuse into the inner pores and effectively block the N-2 adsorption. As a result, the as-prepared A-PEI-300 sample in this work exhibits an excellent CO2 uptake of 3.6 mmol g(-1) and ultrahigh CO2/N-2 selectivity at 0.15 bar and 25 degrees C. In contrast, the higher molecular-weight branched PEI is advantageous at elevated temperature, since the composites can retain high CO2 adsorption capacity owing to the large amount of primary amine groups. Overall, polyamine/MOF composites are shown to be good candidate adsorbents for CO2 capture from flue gas. To achieve the optimal CO2 capture ability, comprehensive optimization of the polyamine and MOF structures should be performed.