Synthesis of nitrogen-containing microporous carbon with a highly ordered structure and effect of nitrogen doping on H₂O adsorption

A nitrogen-containing microporous carbon with a highly ordered structure was synthesized by using zeolite Y as a template. The filling of carbon into zeolite channels was performed by the impregnation of furfuryl alcohol and subsequent chemical vapor deposition (CVD) of acetonitrile. The template was then removed by HF washing. The two-step carbon filling process (the impregnation and the CVD) was found to be essential for obtaining both high microporosity and ordering. This carbon is characterized by its very large surface area (3310 m²/g) and very narrow micropore size distribution (1.0-1.5 nm), and it contains nitrogen of 6 wt %, most of which is quaternary nitrogen. The distribution of nitrogen atoms in the carbon was examined by the detailed analysis of the carbon deposit at each carbon-filling step. The effect of nitrogen doping on the affinity to H₂O molecules was elucidated from the comparison of the H₂O adsorption behavior between this carbon and a nitrogen-free ordered porous carbon with a very similar pore structure. It was found that the nitrogen-containing carbon has a higher affinity to H₂O molecules than the nitrogen-free carbon.