Preparation of Amino Acid-Functionalized Carbon Nanotubes and Study of Their Carbon Dioxide Capture Performance

In postcombustion capture technology, the amine absorption approach is currently the most economical and widely applied method. However, the desorption process still requires a large amount of energy. Therefore, we have prepared a solid acid catalyst, Arg-MWCNTs, aiming to achieve less energy consumption and a higher CO2 desorption rate. At 87 °C in a 30 wt % MEA solution, as opposed to the condition without a catalyst, 0.3 g of Arg-MWCNTs showed the best catalytic performance, with the CO2 desorption amount increasing by 40.82% and the relative heat duty decreasing by 42.14%. After 50 absorption-desorption cyclic experiments, this catalyst exhibited excellent stability. Arg-MWCNTs were characterized by XRD, BET, FT-IR, NH3-TPD, XPS, and CO2-TPD techniques. The results showed that the increase in the number of surface acidic sites could promote proton transfer and accelerate the release of CO2. This study proposes a high-performance and low-cost solid acid catalyst, providing new ideas for CO2 capture technology.