Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (09): 2047-2055.doi: 10.3866/PKU.WHXB201306211

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Effect of Surface Promoters-Modifying on Catalytic Performance of Cu/ZnO/Al2O3 Methanol Synthesis Catalyst

HAO Ai-Xiang, YU Yang, CHEN Hai-Bo, MAO Chun-Peng, WEI Shi-Xin, YIN Yu-Sheng   

  1. Research Institute of Nanjing Chemical Industry Group, Nanjing 210048, P. R. China
  • Received:2013-04-08 Revised:2013-06-18 Published:2013-08-28
  • Contact: HAO Ai-Xiang E-mail:haoax.nhgs@sinopec.com
  • Supported by:

    The project was supported by the China Petroleum& Chemical Corporation on the Manufacture of Catalyst for Methanol Synthesis from Coal-derived Syngas (HX-KA12F001202).

Abstract:

Surface promoters-modified Cu/ZnO/Al2O3 (CZA) catalysts were prepared by a coprecipitationpost impregnation method and evaluated in methanol synthesis fromsyngas. The effects of Zr, Ba, and Mn as promoters, the reaction temperature and run time over CZA and Zr-promoted CZA catalysts on catalytic performance were investigated, respectively. The catalysts were characterized by X-ray diffraction (XRD), N2-sorption, reactive N2O sorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of H2 (H2-TPD), scanning electron microscopy (SEM), and high-resolution transmittance electron microscopy (HR-TEM). The results showed that the space-time yield (STY) of methanol can be increased noticeably over the Zr-or Ba-promoted CZA catalyst before and after the heating treatment of the catalysts. The introduction of Mn as a promoter onto the CZA catalyst led to a decrease in the STY of methanol before heating treatment. The introduction of Zr as a promoter onto the CZA catalyst can decrease the temperature at which the STY of methanol reached the highest value and also improve the catalytic stability. A hydrogen molecule can be adsorbed and then activated over Cu0 and ZnO. The strong interaction between Cu0 and ZnO is favorable for improving the catalytic performance of the CZA catalyst. The decrease in catalytic performance after heating treatment of the CZA catalysts is attributed to a growth of Cu0 crystallites. Based on the results of catalytic performance and characterization, a possible "bidirectional but synchronous catalytic reaction course" in methanol synthesis from syngas over a CZA catalyst is proposed.

Key words: Promoter, Zirconium, Barium, Cu/ZnO/Al2O3 catalyst, Methanol synthesis, Reaction course

MSC2000: 

  • O643