Guo Yangyang, Xu Li, Zheng Jia-Jia, Geng Na, Wang Yaofeng, Yao Mingshui, Zhu Tingyu
CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Innovation Academy for Green Manufacture, State Key Laboratory of Mesoscience and Engineering, Chinese Academy of Sciences, Beijing 100190, China.
Laboratory of Theoretical and Computational Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, China.
Environ Sci Technol. 2024 Dec 17;58(50):22456-22465. doi: 10.1021/acs.est.4c08500. Epub 2024 Dec 9.
Reducing carbon dioxide (CO) emissions has become increasingly urgent for China, particularly in the industrial sector. Striking a balance between a high CO adsorption capacity and long-term stability under practical conditions is crucial for effectively capturing CO from flue gas. In this study, a series of functionalized MFM-136 adsorbents were synthesized in which -NO and -NH groups were grafted onto the kagome lattice of MFM-136. Modifications with -NH groups were found to be highly effective for CO adsorption, specifically, the CO adsorption capacity peaked at 4.35 mmol/g for NH-MFM-136, representing a 55% enhancement more than MFM-136. Concurrently, the CO/N selectivity for NH-MFM-136 was increased 1.57 times. Verification of novel adsorption sites introduced by NH-HL was conducted by using DRIFT analysis and DFT calculations. It turns out that NH-HL modification can effectively mitigate the chemical deposition from the impurity gases and significantly improve the adsorbent's hydrophobicity and its tolerance to impurity gases. Remarkably, the reduction in the CO absorption capacity for NH-MFM-136 was 34% less than that for MFM-136 after 24 h of exposure to simulated flue gas, making NH-MFM-136 a promising candidate for the potential application of stable and selective CO capture under industrial flue gas conditions.
减少二氧化碳（CO）排放对中国而言已变得愈发紧迫，尤其是在工业领域。在实际条件下，实现高CO吸附容量与长期稳定性之间的平衡对于从烟气中有效捕集CO至关重要。在本研究中，合成了一系列功能化的MFM-136吸附剂，其中-NO和-NH基团被接枝到MFM-136的笼目晶格上。发现用-NH基团进行改性对CO吸附非常有效，具体而言，NH-MFM-136的CO吸附容量峰值为4.35 mmol/g，比MFM-136提高了55%。同时，NH-MFM-136的CO/N选择性提高了1.57倍。通过漫反射红外傅里叶变换光谱（DRIFT）分析和密度泛函理论（DFT）计算对NH-HL引入的新吸附位点进行了验证。结果表明，NH-HL改性可以有效减轻杂质气体的化学沉积，并显著提高吸附剂的疏水性及其对杂质气体的耐受性。值得注意的是，在暴露于模拟烟气24小时后，NH-MFM-136的CO吸收容量下降比MFM-136少34%，这使得NH-MFM-136成为在工业烟气条件下稳定且选择性地捕集CO潜在应用的有前景的候选材料。
