Researchers reported the O2-selective reversibleadsorption on mixed-ligand metal-organic frameworks
Author： Time：2022-11-07 Click：
Metal-organic frameworks (MOFs), a new class of materials with highly crystalline and tunable pore properties, have great potential in gas separation and storage. Currently, many MOF materials with coordinatively unsaturated metal sites can bind O2and show high O2selectivities in O2/N2separation. However, most of these MOFs cannot be fully regenerated due to their strong ability to bind O2, which greatly limits their applications in the field of O2/N2separation.
Recently, research group DNL205reported and synthesized two mixed-ligand MOFs containing different coordinatively unsaturated metal sites.These two MOFsexhibited special O2-selective adsorption properties and relatively high O2/N2selectivities, as well as excellent stability and regeneration ability at ambient temperature.
Schematic illustration of the adsorption process onmixed-ligand MOFs and the results of theoretical calculations(Image by LIUHanbang)
The researchers prepared two mixed-ligand metal-organic framework adsorbents M-AIP-BPY with coordinatively unsaturated Co(II) and Ni(II) sites to study their O2/N2separation properties.The results of static adsorption and dynamic breakthrough experiments showed that thesetwo MOFs can not only selectively adsorb O2at ambient temperature, but also achievecompletely regenerate without heating in the desorption process. In addition, they havegood structural and chemical stability in organic solvents and aqueous solutions with different pH values (pH=2~12), which have great potential in practical application. The DFT theoretical calculations were performed to investigate the O2-selective adsorption and regeneration mechanism of these MOFs,and the results showed that the interactions between these materials and O2are stronger than those with N2but relatively moderate, resulting in excellent O2-selective adsorption and regeneration performances at ambient temperature.This work provides inspirations for searching for metal-organic frameworks that can selectively adsorb O2at ambient temperature.
This work, published inChemical Engineering Journal,（https://doi.org/10.1016/j.cej.2022.138214）was supported by the Talent Program for Revitalization of Liaoning Province (XLYC1905017). (Text/Picture LIUHanbangand XU Yunpeng)
Mixed-ligand metal-organic frameworks with coordinatively un-saturated Co(II) and Ni(II) sites for regenerable O2-selective adsorption over N2.HanbangLiu, LipingYang DanhuaYuan, GuangyeLiu, JiachengXing, YunpengXu*, ZhongminLiu, Chemical Engineering Journal,450(2):138214, 2022.
