Acta Phys. -Chim. Sin. ›› 2002, Vol. 18 ›› Issue (04): 340-345.doi: 10.3866/PKU.WHXB20020411

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Synthesis and Activation Mechanism of Coke Based Super Activated Carbons

Xing Wei;Zhang Ming-Jie;Yan Zi-Feng   

  1. State Key Laboratory for Heavy Oil Process,The Key Laboratory of Catalysis,CNPC,University of Petroleum,Dongying 257061
  • Received:2001-08-22 Revised:2001-11-02 Published:2002-04-15
  • Contact: Yan Zi-Feng E-mail:zfyancat@mail.hdpu.edu.cn

Abstract: Coke based super activated carbons (SAC) with higher surface area were synthesized by means of KOH thermoactivation.The structure and properties of SAC samples were extensively investigated by TGDTA and N2 adsorption techniques.Simultaneously,insitu TDDTA and quick activation quenching techniques were designed to investigate the activation mechanism of SAC samples.A twostep activation mechanism,which includes radial activation at moderate temperature and transverse activation at higher temperature,respectively,was tentatively postulated.It indicated that K2O,-O-K+ and -CO-2K+ might be the active sites of radial activation at moderate temperature and fused K+O- and K+ might be the active centers of transverse activation at higher temperature.Of special is that radial activation at moderate temperature may result in the formation of micropores and that this might be the effective way to improve the micropore distribution of SAC samples.In contrary,the transverse activation at higher temperature would lead to the formation of macropore.The formation of super activated carbons was resulted from the radial activation at moderate temperature and subsequent transverse activation at higher temperature.

Key words: Super activated carbons, Activation mechanism, KOH, Radial activation, Transverse activation