Effect of Modified Metal Center in Ligand for CO2 Capture in Novel Zr-Based Porphyrinic Metal鈥揙rganic Frameworks: A Computational Investigation

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• 作者：Wenbin Xu ; Qiuyue Ding ; Pengpeng Sang ; Jing Xu ; Zemin Shi ; Lianming Zhao ; Yuhua Chi ; Wenyue Guo
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：September 24, 2015
• 年：2015
• 卷：119
• 期：38
• 页码：21943-21951
• 全文大小：639K
• ISSN：1932-7455

文摘

A combination of grand canonical Monte Carlo (GCMC) and density functional theory (DFT) simulations was used to investigate the effect of modified metal center in ligand for CO₂ capture in novel Zr-based porphyrinic metal鈥搊rganic frameworks (PCN-224-Ms, M = Mg, Fe, Co, Ni, Mn, and Zr). The results show that the MTCPP ligands (TCPP = tetrakis(4-carboxyphenyl)porphyrin) provide more favorable adsorption sites than the inorganic Zr₆ nodes for CO₂ molecules. The modification of metal center in MTCPP ligand has a remarkable effect on the single-component adsorption of CO₂ compared to CH₄ and thus enhances the adsorption of CO₂ and the selectivity of CO₂ over CH₄. Furthermore, Coulomb interaction between adsorbate and framework plays a dominant role compared with non-Coulomb interaction in the process of adsorption and separation. Among various modified metal centers, the Zr-MTCPP is found to be the best for enhancing the adsorption and selectivity of CO₂. In addition, a small amount of water has a negative effect on the selectivity of CO₂/CH₄, and its influence follows the order PCN-224-Zr > PCN-224-Mn > PCN-224-Ni, depending on the strength of Coulomb interaction between H₂O molecules and frameworks.