Transformation of doped Fe in pitch sphere in carbonization and activationprocesses

Ferrocene was added into the starting pitch in order to produce the pitch-b ased spherical activated carbon with mesopore (PSAC-M) forms of doped Fe in different stages-stabilization, carbonization, and activation-during the p reparation process of the PSAC-M being analyzed using Mossbauer spectroscop y (MES), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) . Ferrocene was oxidized into alpha -Fe2O3 at the stabilization step. The m ajor portion of alpha -Fe2O3 was reduced into alpha -Fe during carbonizatio n at 900 degreesC, which was subsequently transformed into Fe3C by 1200 deg reesC. No obvious sintering or agglomeration of iron particles occurred dur ing carbonization process even when the carbonization temperature was as hi gh as 1200 degreesC. The activation re-oxidized alpha -Fe into gamma -Fe2O3 , which aggregated and grew up along with the activation time and iron cont ent. (C) 2000 Elsevier Science Ltd. All rights reserved.