CO2 Capture Performance and Mechanism of an Amino-Functionalized Acetamide–1-Amino-2-propanol Deep Eutectic Solvent

Abstract A low-cost, low-viscosity, easily synthesized, and environmentally friendly deep eutectic solvent (DES) was fabricated using acetamide (AA) and 1-amino-2-propanol (MIPA) as materials. Performance studies demonstrated that when the molar ratio of AA to MIPA was 1:5, the system exhibited a CO2 adsorption capacity of 0.2198 gCO2/gDES at 303.15 K, at which condition the viscosity and density were measured to be 19.05 mPa·s and 0.9650 g·cm–3. Furthermore, the desorption efficiency remained at 94% after 5 adsorption–desorption cycles, indicating excellent cyclic stability. Through infrared spectroscopy, nuclear magnetic resonance hydrogen spectrum, and quantum chemical calculations, it was found that the DES was primarily stabilized by a hydrogen-bonded network between AA and MIPA molecules, with the amino groups in MIPA serving as the main active sites for the CO2 reaction. The absorption process exhibited a synergistic mechanism combining chemical adsorption (formation of carbamate) and physical adsorption. This study provides theoretical and experimental foundations for the development of efficient and recyclable CO2 capture materials.