Exfoliated vermiculite nanosheets supporting tetraethylenepentamine for CO2 capture

• Published in: Results in materials Vol. 7; p. 100102
• Main Authors: Zhang, Yi, Chen, Mingkun, Li, Guanchu, Shi, Changrui, Wang, Bohao, Ling, Zheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2020; Elsevier
• Subjects: Clay; CO2 capture; Composites; Exfoliation; Two-dimensional materials; Two-dimensional materials; Clay; Composites; CO2 capture; Exfoliation
• ISSN: 2590-048X; 2590-048X
• DOI: 10.1016/j.rinma.2020.100102

CO2 capture is a critical process to reduce CO2 emission into the atmosphere. Here we report a novel and inexpensive composite adsorbent for capturing CO2. The composite was prepared by supporting tetraethylenepentamine (TEPA) onto exfoliated vermiculite (E-VER) nanosheets using wet-impregnation and freeze-drying methods. Vermiculite, as a cheap and natural abundant clay, was delaminated into ultrathin nanosheets via liquid-phase exfoliation. The negatively charged E-VER has exposed surfaces and a large surface area, which is ideal for supporting TEPA with the desired loading. It was found out that the TEPA loading has a crucial impact on the pore structures, surface areas, and the CO2 adsorption capacities. E-VER-TEPA-2% with a TEPA loading of 2% demonstrates the optimal performance for CO2 capture, showing a CO2 adsorption capacity of 29.5 ​mmol/g at 45 ​bar and 25 ​°C and 22.6 ​mmol/g at 40 ​bar and 75 ​°C. The E-VER/TEPA composites are compressible, a volumetric capacity of 29.93 ​mmol/cm3 was obtained for E-VER-TEPA-2% at 45 ​bar and 25 ​°C after being compressed at 20 ​MPa. Furthermore, E-VER/TEPA composites exhibited excellent cyclic stability over six cycles and long-time heat-treatment.