The Synergistic Character of Highly N-Doped Coconut-Shell Activated Carbon for Efficient CO2 Capture

The coconut shell-based activated carbon (AC) surface was effectively anchored with amine moieties with acid treatment followed by tetraethylenepentamine (TEPA) anchoring. The activated carbon surface enhanced with basicity is likely to increase the sorbent properties towards CO2 adsorption. The AC surface was modified by varying TEPA concentrations. After amine doping, significant loss in textural property indicates their occupation inside the pores and surfaces. Further, the samples were thermally activated to retrieve the textural properties. The physicochemical properties of modified carbon were characterized using BET, TPD, FT-IR, Raman spectroscopy and elemental composition. The amine-modified and thermally activated carbons were tested for CO2 adsorption up to 25 bar at 25 degrees C. The acid-base properties of N-doped carbons were evaluated using isopropanol as a model test reaction at atmospheric pressure. The IPA reaction products of acetone and propene were quantified for their acid-base nature and correlated to CO2 adsorption capacities. The CO2 adsorption capacity increases by tailoring synergistic properties between surface basicity and micropores. Hence, 20 % TEPA-derived nitrogen-enriched carbon reveals a higher yield of acetone 73 %, which in turn enhanced CO2 adsorption capacity of 9.9 mmol/g, and it is found to be a suitable applicant for CO2 capture.

Automated summary

The study focuses on modifying nitrogen-doped activated carbon with TEPA treatment and thermal activation to enhance CO2 adsorption capacity. Results show that tailoring synergistic properties between surface basicity and micropores can increase CO2 adsorption capacity.