Nitrogen doped porous carbons play appreciable roles as materials in various fields such as energy storage, oxygen reduction and gas adsorption. In relation to carbon dioxide (CO2) capture, the presence of doped nitrogen enhances adsorption of acidic CO2 molecules, whereas the volume of accessible ultra-micropores (pore diameter &lt;0.7nm) in the material determines its CO2 sorption capacity. In-situ activation of carbons with the presence of incorporated Potassium based organic salts, has become a growing interest due to single-step carbonization/activation, facileness and efficiency. This study elaborates a one-pot synthesis strategy to produce nitrogen doped carbon spheres with high ultra-microporosity, with the aim to achieve high CO2 uptake. Nitrogen doping was performed by co-polymerizing ethylenediamine and polypyrrole with resorcinol and formaldehyde primary precursors. Microporosity in the three series of carbon spheres was tuned by varying the amount of potassium citrate in the synthesis mixture, followed by carbonization of the resulting polymer spheres under N2 at 700 oC. All the in-situ carbon spheres possessed narrow pore size distributions below 1nm and unprecedented CO2 uptake of 7.35 mmol g-1 at 0 oC and 1 bar pressure was achieved for CS-Py-K100 sample, which possessed a high ultra-micropore volume of 0.42 cm3 g-1. This uptake was further tuned up to 7.60 mmol g-1 busing activated polypyrrole carbon spheres.

Dual optimization of microporosity in carbon spheres for superior CO2 capture

256th National Meeting (2018)

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