Importance of additional aliphatic structures generated from in-situ oxidation in development of extra pores in activation of spring jasmine wood

Aliphatic organics are reactive components of biomass in activation, playing important roles in pore development. They could be consumed with progress of activation while introducing external O 2 might create additional aliphatic structures via oxidation, probably facilitating generation of extra pores in resulting activated carbon (AC). This was investigated herein by activation of spring jasmine wood with ZnCl 2 or K 2 C 2 O 4 in presence of 11 % or 5 % O 2 at 550 or 700 °C. The results suggested that the oxygen added diminished yield of AC O 2 ZnCl 2 by 21.7 % and yield of AC O 2 K 2 C 2 O 4 by 29.0 %, resulting from partial oxidation of carbonaceous organics on nascent AC. Nonetheless, O 2 presence promoted pore development, increasing S BET from 1833.8 m 2 g -1 for AC N 2 -ZnCl 2 to 2018.2 m 2 g -1 for AC O 2 ZnCl 2 . The S BET of AC O 2 K 2 C 2 O 4 also increased by 35.6 % with presence of O 2 . Oxidization of nascent AC generated more oxygen-containing species that actively involved in polymerization with ZnCl 2 or cracking with K 2 C 2 O 4 to form more pores. Additionally, O 2 presence generated smaller pores in AC O 2 ZnCl 2 while larger ones in AC O 2 -K 2 C 2 O 4 , enhancing the latter AC for adsorption. Oxidation reactions could also form the AC with oxygen-rice surface and hydrophilic nature, which negatively affect aromatization and reduced interplanar spacing of carbon crystals in AC.