CO2 removal potential of carbons prepared by co-pyrolysis of sugar and nitrogen containing compounds

The nitrogen enrichment of active carbons is reported to be effective in enhancing the specific adsorbate-adsorbent interactions for CO2. In this work, nitrogen-enriched carbons were prepared by co-pyrolysis of sugar and a series of nitrogen compounds with different nitrogen functionalities. The results show that although the amount of nitrogen incorporated to the final adsorbent is important, the N-functionality seems to be more relevant for increasing CO2 uptake. Thus, the adsorbent obtained from urea co-pyrolysis presents the highest nitrogen content but the lowest CO2 adsorption capacity. However, the adsorbent obtained from carbazole co-pyrolysis, despite the lower amount of N incorporated, shows high CO2 uptake, up to 9 wt.%, probably because the presence of more basic functionalities as determined by XPS analysis.