Role of Hydrogen Peroxide Preoxidizing on CO2 Adsorption of Nitrogen-Doped Carbons Produced from Coconut Shell

In this work, the coconut shell was preoxidized by hydrogen peroxide, before it was treated by the ammoxidation process and potassium hydroxide activation to synthesize nitrogen-doped porous carbons. The resulting sorbents exhibit significantly higher nitrogen content and narrow microporosity than the control sample without H2O2 pretreatment. Consequently, these sorbents are found to demonstrate high carbon dioxide uptake at 1 bar, such as 4.47 mmol g–1 at 25 °C and 6.79 mmol g–1 at 0 °C. In addition, these sorbents possess high CO2/N2 selectivity, stable reusability, high initial heat of CO2 adsorption, and high dynamic CO2 capture capacity under simulated flue gas conditions. These superior CO2 adsorption properties make them highly competitive among all the carbonaceous adsorbents for CO2 capture.