A Microporous MOF with Inorganic Nitrate Ions Immobilized on a Porous Surface Displaying Efficient C<sub>2</sub>H<sub>2</sub> Separation and Purification
Xiaoxia Gao, Haoyan Zhong, Yingying Zhang, Yongna Yao, De‐Li Chen, Yabing He
Abstract
A microporous MOF based on a heterotopic ligand was successfully synthesized under solvothermal conditions and fully characterized using single‐crystal and powder X‐ray diffraction, TGA, FTIR, and microanalyses. Single‐crystal X‐ray diffraction analyses showed that the title MOF contains rich inorganic nitrate ions decorating the channel surface that can serve as C 2 H 2 recognition sites. Its selective gas adsorption properties towards C 2 H 2 over CO 2 and CH 4 were evaluated by single‐component equilibrium adsorption measurements and IAST calculations, establishing its promising potential for C 2 H 2 separation and purification. At ambient conditions, the C 2 H 2 uptake capacity reaches 92.2 cm 3 (STP) g –1 , while the IAST‐predicted adsorption selectivities are up to 30.6 and 4.5 for the equimolar C 2 H 2 ‐CH 4 and C 2 H 2 ‐CO 2 binary gas mixtures, respectively. Furthermore, DFT computation studies revealed that the inorganic nitrate ion plays a very important role for preferential adsorption of C 2 H 2 over CO 2 and CH 4 .