One-Step Synthesis of Cellulosed-Based Nitrogen-Doped Carbon Aerogel and Its CO₂ Adsorption Performance

Abstract

CO 2 capture and storage (CCS) from point sources is an important part of CO 2 emission reduction technologies. In particular, adsorbents with high capacity and selectivity are needed to reduce the cost of CCS technologies. Herein, we report the controlled synthesis of N-doped carbon materials, which exhibit high CO 2 /N 2 selectivity and CO 2 adsorption capacity. Specifically, cellulose-based nitrogen-doped carbon aerogels (CNCAs) were prepared using cellulose as a precursor and dissolving it in the mixed solution of NaOH and urea, followed by hydrothermal polymerization, freeze-drying, carbonization and activation. During the experiment, the effects of NaOH and urea on the formation and microstructure of carbon aerogels (CAs) were tested, and the impacts of carbonization/activation temperature on the pore structure, nitrogen content, microcrystalline structure and CO 2 adsorption performance were further investigated. Impressively, for a simulated flue gas with a composition of 15% vol of CO 2 and 85% vol of N 2 , the CNCA-750 adsorbent prepared in this work showed excellent adsorption and separation performance for CO 2 . The adsorption capacity can reach 3.65 mmol CO 2 /g and that selectivity can reach 19.69. Compared with other absorbents, it has excellent water resistance, high chemical stability, low cost and lower adsorption heat. Comprehensively, CNCAs have great prospects in the ultralow emission of industrial flue gas.