Enhanced capacity in cellulose aerogel for carbon dioxide capture through modified by metal-organic framework

Microporous metal-organic frameworks (MOF) exhibit excellent carbon dioxide (CO₂) adsorption performance and selectivity for CO₂/N₂ separation. However, the challenges associate with the recycling and reuse of MOF powders hinder their practical applications. To address these limitations, a flexible and stable MOF-based composite material was designed by immobilizing UiO-66(Zr)-(OH)₂ onto cellulose nanofibers (CNFs) aerogels (MOF-CNFs), which featured high porosity. Experimental results showed that MOF-CNFs exhibited sensitivity to CO₂ adsorption at low pressure and achieved a CO₂ adsorption capacity of 1.8 mmol/g at 0.15 bar under the 298 K. This represented an 8.8 % improvement compared to the MOF. Ideal adsorbed solution theory (IAST) calculations indicated selectivity for CO₂/N₂ mixtures (molar ratio 15:85) as high as 66. After eight adsorption-desorption cycles, the CO₂ adsorption capacity retained 97 % of its initial value. These results highlighted the significant potential of MOF-CNFs as reusable and highly efficient CO₂ separation adsorbents for practical applications, such as flue gas capture.