(253e) Hierarchichal N-Rich Nanoporous Carbon Derived from Polybenzoxazine Via Sol-Gel Process and Its Application As the CO2 Adsorbent

Nanoporous carbons which have micro-mesopores structure, high surface area, and nitrogen active sites were synthesized via a sol-gel  process by using polybenzoxazine as a polymer precursor. The silica colloidal particles with specific diameter were incorporated as hard templates. The resulting polybenzoxazine gel was dried at ambient pressure before pyrolysis in an inert atmosphere, and underwent the activation process under CO₂ at 900°C for 3 h. The morphology of carbons at different silica loading concentration was investigated by FE-SEM. The effect of pyrolysis temperature was varied to obtain nitrogen-rich nanoporous carbon and confirmed by using XPS and elemental analyzers. The Autosorp 1-MP was carried out to determine the surface area, particle size and pore volume of the resulting nanoporous carbon. It was found that using 40% wt. of silica as a template, nanoporous carbon with the highest surface area of 945 m2/g and average pore size of 15.44 nm was obtained. These results imply that silican can be used to inprove the specific surface arean and total pore volume by adding in a proper concentration. From the adsorption results, the resulting activated carbon using 40%wt. silica colloidal template exhibited the highest CO₂ uptake (1.233 mmol/g at 30ºC, 1 bar). The adsorption of CO₂ was increased because the pyridine and pyridone types of nitrogen reacted with CO₂ gas as shown by the XPS spectra, as well as the physical adsorption of the micro-meso porous structure. The effects of temperature and pressure on the efficiency of this adsorbent will be further investigated.