Lignin-regulated MOF@lignocellulose aerogels for enhanced selective carbon dioxide adsorption.

Metal-organic frameworks (MOFs) are widely used in gas adsorption due to their microporous structure and high performance. However, MOFs have limitations, including poor mechanical properties and difficulties with recovery. To address these limitations, we used a lignocellulose composite aerogel as a substrate to enhance the properties of MOFs. In this study, we focused on controlling the morphology, solidification, and size of MOFs through the addition of lignin to optimize their in situ growth. The aerogels were evaluated for selective CO2 adsorption. The addition of 30 wt% deep eutectic solvent-extracted lignin (DESL) to the MOF@CNFs/DESL30G aerogels increased the specific surface area to 379.43 m2/g, resulting in a 102.83 % improvement in CO2 adsorption capacity. The selective adsorption coefficient for CO2 over CH4 reached 7.5. After six adsorption cycles, the aerogels retained 70 % of its initial CO2 adsorption capacity.