High‐Performance Activated Carbons Synthesized from Nanocellulose for CO2 Capture and Extremely Selective Removal of Volatile Organic Compounds. (27th December 2017) - Xu, Chao
Abstract: A series of sustainable activated carbons (ACs) with large surface areas and tunable pore sizes is synthesized from Cladophora cellulose and its chemically modified derivatives in a one‐step physical carbonization/activation process. The molecular structure of the cellulose precursors and the carbonization/activation atmosphere (N2 or CO2 ) significantly influence the pore structure of the ACs. When using oxidized cellulose and its further cross‐linkages as the precursor, the ACs have a large volume of ultramicropores (pore diameter< 0.8 nm). Activation in CO2 results in ACs with surface areas up to 1241 m 2 g −1 . These ACs have a high CO2 uptake capacity (2.29 mmol g −1 at 0.15 bar, 5.52 mmol g −1 at 1 bar; 273 K) and a high CO2 –over–N2 selectivity (42 at 273 K). In addition, the capacity of the ACs to adsorb vapors of volatile organic compounds (VOCs) is remarkable, with values up to 0.97 mmol g −1 at very low VOC concentrations (200 ppmv). The ACs have ultrahigh VOCs–over–N2 selectivity up to 9.35× 10 3 at 293 K for 0.02 vol%/99.8 vol% of benzene/N2 mixture. It is anticipated that these ACs will be useful as sorbents for the postcombustion capture of CO2 and for indoor removal and direct air capture of various VOCs. Abstract : A facile approach to prepare ultramicroporous activated carbons is developed by one‐step carbonization/activation of Cladophora cellulose and its chemically modified derivatives. The rich ultramicropores result in activated carbons with a high efficiency for CO2 separation and volatile organic compounds removal.