Single site Ni(II) anchored tetraethylene pentamine for enhancing CO2 kinetic adsorption rate and long-term cyclic stability
Single site Ni(II) anchored tetraethylene pentamine for enhancing CO2 kinetic adsorption rate and long-term cyclic stability
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DOI：
10.1016/j.cej.2022.135211
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发表时间：
2022-02
影响因子：
15.1
通讯作者：
Shi-Lun Zhang;Wenbin Chen;J. Mu;Jianyu Han;Chaofeng Zhang;Zhuyan Gao;Jian Zhang;Yehong Wang;Feng Wang
中科院分区：
文献类型：
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作者：
Shi-Lun Zhang;Wenbin Chen;J. Mu;Jianyu Han;Chaofeng Zhang;Zhuyan Gao;Jian Zhang;Yehong Wang;Feng Wang
快速动力学吸附和长期循环稳定性是固体胺吸附剂工业化的两个主要障碍。有机胺在载体孔结构中的形态和分布对CO2的吸附速率和稳定性有很大影响。在这项工作中，我们提出了一种策略，通过锚定四乙烯五胺（TEPA）与单网站镍（II）在商业介孔硅胶（SG）的孔增强分散和稳定性。通过分子动力学模拟，探讨了吸附剂制备过程中TEPA分子的微观形态和动力学行为，证明TEPA在多孔结构中的锚定作用得到改善，从而增强了传质，提高了动力学吸附速率。在TEPA负载量为30wt%时，锚定Ni-TEPA/SG吸附剂的动态吸附速率比TEPA/SG吸附剂快37.5%，达到最大吸附容量90%所需的时间缩短了6倍。此外，优化后的Ni-TEPA/SG吸附剂在20次循环后对CO2的吸附性能基本保持不变，进一步证实了该方法在提高固体胺吸附剂的动力学吸附速率和循环稳定性以及促进其工业化方面的潜力。
Rapid kinetic adsorption and long-term cyclic stability are two of the major obstacles to the industrialization of solid amine adsorbents. The morphology and dispersibility of the organic amine in the pore structure of the support can strongly affect the adsorption rate and stability of CO2. In this work, we propose a strategy that enhances the dispersion and stability of tetraethylene pentamine (TEPA) via anchoring TEPA with single site Ni(II) in the pore of the commercial mesoporous silica gel (SG). The microscopic morphology and dynamic behavior of TEPA molecules in the adsorbents preparation process were explored by molecular dynamics simulation, which proved that the dispersibility of anchored TEPA in the porous structure has been improved, resulting in enhanced mass transfer and increased kinetic adsorption rate. The anchored Ni-TEPA/SG adsorbents exhibit a 37.5% faster kinetic adsorption rate than TEPA/SG adsorbents at 30 wt% TEPA loading, and the time required to reach 90% of maximum adsorption capacity is shortened by 6 times. Besides, the CO2adsorption performance of the optimized Ni-TEPA/SG adsorbent remains unchanged after 20 cycles, consolidating the potential of our proposed strategy in improving the kinetic adsorption rate and cyclic stability of solid amine adsorbents as well as promoting its industrialization.