Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (07): 1730-1736.doi: 10.3866/PKU.WHXB20110719

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Catalytic Activities for the Complete Oxidation of Ethylene over Au-Cu/Co3O4 Catalysts

XUE Wen-Juan1, ZHANG Xin-Yan1, LI Peng1, LIU Zhao-Tie2, HAO Zheng-Ping1, MA Chun-Yan1   

  1. 1. Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P. R. China;
    2. Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi′an 710062, P. R. China
  • Received:2011-04-07 Revised:2011-05-13 Published:2011-06-28
  • Contact: HAO Zheng-Ping, MA Chun-Yan E-mail:zpinghao@rcees.ac.cn. cyma@rcees.ac.cn

Abstract:

A series of Au-Cu/Co3O4 catalysts with different mass fractions of Cu were synthesized by a two-step method that consists of depositing gold and copper onto a Co3O4 support, which was synthesized by coprecipitation. The effect of copper on the catalytic activity of Au-Cu/Co3O4 was evaluated for the complete oxidation of ethylene at different temperatures and the prepared catalysts were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), H2 temperature- programmed reduction (H2-TPR), and O2 temperature-programmed desorption (O2-TPD). The results show that Au-Cu/Co3O4 bimetal catalysts exhibit higher catalytic activities than the Au/Co3O4 catalyst. At a gold loading amount of 4% (w, mass fraction) the AuCu3/Co3O4 catalyst gives higher catalytic activity compared to catalysts AuCu/Co3O4 and Au3Cu/Co3O4. Ethylene conversion was 15.3% for AuCu3/Co3O4 even at 0 ℃ whereas at 120 ℃ the full conversion of ethylene was obtained. The results of XRD and HRTEM indicate the formation of an Au-Cu alloy in AuCu3/Co3O4. However, we have found that the majority of Cu is present in the form of Cu2O in Au3Cu/Co3O4. The interaction between Au and Cu on the surface of the catalysts decreases the particle size of the gold and, therefore, it is much easier to activate ethylene. H2-TPR and O2-TPD results show that the high reduction ability and the high intensity of surface oxygen active species contribute to the excellent catalytic activity of the AuCu3/Co3O4 catalyst.

Key words: Nano-gold catalyst, Au-Cu/Co3O4, Ethylene, Catalytic oxidation, Au-Cu alloy

MSC2000: 

  • O643