(639e) Amine-Functionalized Graphene Oxide Applied to Temperature-Programmed Carbon Dioxide Adsorption and Desorption

An excellent amine-functionalized carbon-based material (referred as N-FGO), with superior thermal stability (can withstand up to 500°C), was synthesized from graphene oxide (GO). Functionalization was performed in supercritical conditions using grafting technique. Aqueous ammonia was utilized as an amine source. Successful amine-functionalization was confirmed by X-ray photoelectron spectroscopy (XPS) showing approximately 9% increase in nitrogen content. Evaluation of pore characteristics revealed a decrease in surface area compared to the as-prepared GO. The CO₂ adsorption performances of GO and N-FGO were evaluated using a temperature-programmed adsorption. N-FGO exhibited a 130% increase in adsorption capacity than GO despite the decrease in surface area. This can be attributed to the nitrogen content of the N-FGO. Significantly, the adsorption capacity of the N-FGO is 140 times higher than results of other related pioneering studies involving amine-functionalized carbon materials. Moreover, the optimum temperature required for adsorption using the N-FGO is 80°C, which is higher than the conventional adsorption temperature of 25°C. This is an advantage, as less energy will be required to cool down flue gases prior to adsorption. Furthermore, the regenerability of the N-FGO after adsorption was investigated by repeated temperature-programmed adsorption/desorption (TPA/TPD) process. N-FGO exhibited high stability and regenerability indicated by slow degradation rate and reusability. Desorption study showed the easy removal of CO₂ from N-FGO after adsorption requiring only up to 200áµ’C at an N₂ environment.