Unveiling the Temperature Influence on the Sorptive Behaviour of ZIF-8 Composite Materials Impregnated with [CnMIM][B(CN)4] Ionic Liquids

Processes

Isabel A. A. C. Esteves¹  Laura M. Esteves¹  Tiago J. Ferreira¹  José M. S. S. Esperança¹ 

[1] LAQV/REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Almada, Portugal;

关键词: CO₂ separation;    gas adsorption;    ionic liquids (ILs);    metal-organic frameworks (MOFs);    composite porous materials;   

DOI  :  10.3390/pr10020247

来源: DOAJ

【 摘 要 】

Composite sorbent materials (IL@MOF) with a metal-organic framework (MOF) ZIF-8 and [B(CN)₄]⁻-based ionic liquids (ILs) were produced for the first time. Characterization results indicate the successful IL impregnation and conservation of the ZIF-8 crystalline structure and morphology. The data collected from the nitrogen (N₂) physisorption at 77 K suggest that these IL@ZIF-8 materials are nonporous as their textural properties, such as BET specific surface area and total pore volume, are negligible. However, CO₂, CH_4, and N₂ adsorption/desorption measurements in the IL@ZIF-8 composites at 303 and 273 K contradict the N₂ data at 77 K, given that the obtained isotherms are Type I, typical of (micro)porous materials. Their gas adsorption capacity and ultramicroporous volume are in the same order of magnitude as the pristine microporous ZIF-8. The case study [C₆MIM][B(CN)₄] IL revealed a high affinity to both CO₂ and CH₄. This compromised the selectivity performance of its respective composite when compared with pristine ZIF-8. This work highlights the importance of accurate experimental gas adsorption/desorption equilibrium measurements to characterize the adsorption uptake and the porous nature of adsorbent materials.

【 授权许可】

Unknown