N-doped porous carbons for CO₂ capture: Rational choice of N-containing polymer with high phenyl density as precursor

N-doped porous carbons (NPCs) are highly promising for CO₂ capture, but their preparation is severely hindered by two factors, namely, the high cost of N-containing polymer precursors and the low yield of carbon products. Here we report for the first time the fabrication of NPCs through the rational choice of the polymer NUT-4, with low cost and high phenyl density, as precursor. For the material NPC-600 obtained from carbonization at 600°C, the yield is as high as 52.1%. The adsorption capacity of CO₂ on NPC-600 reaches 6.9 mmol/g at 273 K and 1 bar, which is obviously higher than that on the benchmarks, including 13X zeolite (4.1 mmol/g) and activated carbon (2.8 mmol/g), as well as most reported carbon materials. Our results also demonstrate that the present NPCs can be completely regenerated under mild conditions. The abundant microporosity and “CO₂-philic” (N-doped) sites are responsible for the adsorption performance.