Preparation of HKUST-1/PEI mixed-matrix membranes: Adsorption-diffusion coupling control of small gas molecules

• DOI: 10.1016/j.memsci.2021.120070
• Publication Date: 2021-11-13T17:39:44Z
• Authors: Yanjiao Wang; Ge Yang; Hailing Guo; Xianglong Meng; Guodong Kong; Zixi Kang; Rémy Guillet-Nicolas; Svetlana Mintova
• Keywords: capping agent; [CHIM] Chemical Sciences; [CHIM]Chemical Sciences; 02 engineering and technology; HKUST-1 nanocrystals; 540; interfacial defects; gas separation; 0210 nano-technology; mixed-matrix membrane

HKUST-1 nanocrystals (50-80 nm) were homogeneously dispersed in a polyetherimide (PEI) polymer matrix. The use of a capping agent (sodium formate) 2 prevented the agglomeration of HKUST-1 nanocrystals in the casting solution. The highly dispersed HKUST-1 nanocrystals were found to strengthen the interactions with the PEI and minimize the interfacial holes by providing more accessible Cu unsaturated metal sites for the C=O bonds on the five-membered rings of the PEI matrix. The PEI membrane loaded with 30 wt. % HKUST-1 nanocrystals (30-N-HKUST-1/PEI) showed a high H 2 permeability (193.3 Barrer at 25 °C under 1.5 bar) and good ideal H 2 /CH 4 and H 2 /CO 2 selectivity factor of 101.7 and 20.6 in a single gas test, respectively. In the gas mixture test, it also showed a good separation performance, i.e., a H 2 /CH 4 and H 2 /CO 2 selectivity factor of 82.4 and 16.5 was measured, respectively. The 30-N-HKUST/PEI membrane was tested in a gas mixture at different temperatures (25-100 °C), different pressures (0-3 bar) and various time (5-72 h) to study the performance in more realistic conditions thus to be further considered in the separation of syngas.