Anionic NbO-type copper organic framework decorated with carboxylate groups for light hydrocarbons separation under ambient conditions

• Published in: Journal of materials science 2018-06, Vol.53 (12), p.8866-8877
• Main Authors: Liu, Xiuping, Li, Xue, Li, Jing, Li, Guixia, Guo, Sheng, Zhu, Houyu, Zhao, Lianming, Hao, Chunlian, Guo, Wenyue
• Format: Article
• Language: English
• Subjects: Adsorption; Characterization and Evaluation of Materials; Chemical Routes to Materials; Chemistry and Materials Science; Classical Mechanics; Computer simulation; Copper; Crystallography and Scattering Methods; Fine chemicals; First principles; Hydrocarbons; Materials Science; Metal-organic frameworks; Methane; Monte Carlo methods; Natural gas; Niobium oxides; Organic chemistry; Polymer Sciences; Raw materials; Separation; Solid Mechanics; Surface active agents
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-018-2155-1

Light hydrocarbons are important raw materials for industrial products and fine chemicals. The storage and separation of C 1 –C 3 hydrocarbons are vital to their practical use. Here, we report efficient C 1 –C 3 hydrocarbon adsorption and separation with a NbO-type anionic copper metal–organic framework with uncoordinated –COO − groups ([Cu 2 ( L )·(H 2 O) 2 ]·2H 2 O·3DMA·(CH 3 ) 2 NH 2 ) ( 1 ). Complex 1 exhibited large C 2 H 2 (190 cm 3 g −1 ), C 2 H 4 (147 cm 3 g −1 ), C 2 H 6 (156 cm 3 g −1 ), C 3 H 6 (170 cm 3 g −1 ), and C 3 H 8 (173 cm 3 g −1 ) uptakes and high selectivities for C 2 H 2 /CH 4 (32.3), C 3 H 6 /CH 4 (152), and C 3 H 8 /CH 4 (127) under ambient conditions. The excellent cycling performance of the material was reflected by only 9.2 and 10.9% losses of the C 2 H 2 and C 3 H 6 storage capacities even after ten cycles of adsorption–desorption tests. First-principles calculations and Grand canonical Monte Carlo simulations further revealed that not only the open metal sites but also the –COO − groups played a key role in the high C 2 –C 3 hydrocarbon uptakes. The results obtained in this study suggest that anionic 1 is a promising candidate for light hydrocarbon adsorption and natural gas purification at room temperature.