Enhanced CO₂ Adsorption Capacity in Highly Porous Carbon Materials Derived from Melamine-Formaldehyde Resin

Abstract

The present study explores the synthesis of N-doped carbon materials with large surface porosity using commercial melamine-formaldehyde resin as the precursor and KOH as the activator. The resin was carbonized first and then activated by KOH with varying KOH amount and activation temperature. Notably, the as-obtained sorbents display advanced porosity with the highest surface area and pore volume of 1591 m2/g and 0.74 cm3/g, respectively, along with high N content ranging from 6.43 to 18.34 wt %. Remarkably, maximum CO2 capture amounts of 5.42 and 3.52 mmol/g were accomplished at 0 and 25 °C, 1 bar for as-synthesized carbons. Systematic studies point out that narrow microporosity is the major factor determining the CO2 uptake of these carbons under ambient pressure. Furthermore, these sorbents display notable CO2 selectivity, rapid adsorption kinetics, moderate heat of adsorption, substantial dynamic CO2 capture capacity, and stable recyclability. These results underscore the potential of melamine-formaldehyde resin-derived N-doped porous carbon as an efficient and versatile adsorbent for CO2 capture.