Fabrication of vertical structure type bimetallic MOF@ biomass aerogels for efficient CO2 capture and separation

Abstract

Effectively capturing carbon dioxide (CO₂) is crucial for environmental protection. In this research, we synthesized a composite aerogel (CSA-n) by integrating a bimetallic metal-organic framework (Mg/Co-MOF-74) with biomass materials (cellulose/chitosan) using an in situ mineralization approach. This composite aerogel exhibited enhanced CO₂ adsorption capabilities than pure biomass aerogel. At 298 K and 100 KPa, the CO₂ adsorption capacity of CSA-3 reached 6.4 mmol/g, an increase of 16.4 % compared to pure MOF. The significant improvement of CO₂ uptakes could be attributed to the more complex pore structure of the composite aerogel compared to pure MOF. Additionally, simulations based on the ideal adsorption solution theory (IAST) showed that the separation factors of CSA-3 for CO₂/N₂ and CO₂/CH₄ gas mixtures were 594.3 and 43.4, respectively. Furthermore, the composite aerogel exhibited excellent cyclic stability. After 10 cycles, the CO₂ adsorption capacity of CSA-3 remained at 96.8 %. The results suggest that this bimetallic metal-organic framework @biomass hybrid aerogel holds great potential for CO₂ adsorption and separation applications.