Plasma-mediated F-doped activated carbon embedded with N and S atoms for the effective removal of CO2 gas
Chaehun Lim, Seo Gyeong Jeong, Naeun Ha, Seongjae Myeong, Chung Gi Min, Yunhua Yu, Xiaoping Yang, Young‐Seak Lee
Abstract
In this work, we suggest NF 3 plasma-treated vacuum residue oil(VR)-based activated carbon(AC) as a highly effective CO 2 adsorbent. The VR was pyrolyzed and activated under various conditions to determine the optimal activation conditions. The VR800AC, which have highest specific surface area of 1792.2 m 2 /g was selected as optimal sample and then, the VR800AC was treated with NF 3 plasma. Effects of NF 3 plasma treatment on the porosity and functionality of the VR-based AC were evaluated. Surface etching from plasma discharge induced micropores in the AC and enlarged the specific surface area. Moreover, fluorine functional groups were introduced after NF 3 plasma treatment. Synergistic effect of the N and S groups embedded in VR, F-groups derived from NF 3 plasma treatment, and micropores generated from plasma etching enhanced the CO 2 adsorption capacity of the NF 3 plasma-treated AC. After 60 s of NF 3 plasma treatment, the plasma-treated AC showed 14.5 % increased specific surface area, 13 % of surface fluorine groups, and revealed to have a CO 2 adsorption capacity of 4.55 mmol/g at 298 K and 1 bar, which is superior to that of the other heteroatom-doped ACs. Moreover, the NF 3 plasma-treated VR-based AC has excellent CO 2 /N 2 adsorption selectivity and high CO 2 adsorption cyclability.