Preparation and CO2 Adsorption Performance of Nitrogen-Doped Carbon Derived from Phenolic Resin

Carbon dioxide emissions, particularly from large point sources such as fossil-fuel power plants, represent a primary driver of global warming. Although various carbon-based adsorbents have been developed for carbon capture applications, most existing materials exhibit limited CO2 adsorption capacity at flue gas-relevant partial pressures and are susceptible to interference from impurity components. In this study, a series of nitrogen-doped carbons was prepared from commercial phenolic resin and melamine via a two-step carbonization–activation process. The effects of precursor-to-dopant ratio and thermal conditions on CO2 adsorption were systematically investigated. The results indicated that CO2 uptake was influenced by specific surface area, nitrogen content, micropore volume, and total pore volume, with a maximum adsorption capacity of 2.455 mmol·g−1 and selectivity over 28 at 25 °C and 1 bar. The series also exhibited excellent cycling stability (<1% loss after 5 cycles) and fast kinetics (>90% uptake within 3 min), suggesting its potential applicability in flue gas CO2 capture.