Effect of precursor preoxidation on the structure of phenolic resin-based activated carbon spheres

Activated carbon spheres with 3D hierarchical porous structure were prepared from phenol–formaldehyde resins with oxidation treatment in air and physical activation in an inert atmosphere. Based on the results of thermogravimetric analysis, infrared spectrometer (IR), scanning electron microscopy (SEM) and nitrogen adsorption/desorption, the effect of preoxidation on the morphology and structure of activated carbon spheres was investigated. The results show that decomposition and crosslinking reactions occur during the preoxidation and the structural changes of precursor generated by the preoxidation lead to differences in the pore structure of activated carbon spheres. The carbon spheres exhibit the unique 3D hierarchical porous structure, high specific surface area of 1897 m2/g and high pore volume of 2.22 cm3/g.