Synthesis of a nitrogen-doped porous carbon monolith and its use for CO₂ capture

Monolithic nitrogen-doped porous carbon was synthesized by the copolymerization of resorcinol and formaldehyde in the presence of L-lysine as the catalyst at the ambient conditions. The carbon is designated RFL. In order to increase the active nitrogen content, nitrogen-rich melamine was added, and the resulting material (RFLM) has more nitrogen-containing functional groups, and a higher specific surface area and pore volume than the original RFL. Glutamic acid was used to control the rate of polymerization, resulting in a porous carbon (RFLMG) with optimized texture properties. However, samples of RFLM and RFLMG show lower CO₂ adsorption capacities than do the RFL series, indicating that there is no explicit linear relationship between the nitrogen content and CO₂ adsorption capacity. This may be directly caused by the different form of the nitrogen-containing functional groups.