Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (08): 1964-1970.doi: 10.3866/PKU.WHXB201205213

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Structure and Performance of Cu-Fe Bimodal Support for Higher Alcohol Syntheses

LIU Jian-Guo1,2, DING Ming-Yue1, WANG Tie-Jun1, MA Long-Long1   

  1. 1. Key Laboratory of Renewable Energy and Natural Gas Hydrate, Chinese Academy of Science, Guangzhou 510640,P.R. China;
    2. Graduate School of Chinese Academy of Science, Beijing 100049, P.R.China
  • Received:2012-03-13 Revised:2012-05-18 Published:2012-07-10
  • Contact: WANG Tie-Jun E-mail:wangtj@ms.giec.ac.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51161140331, 51036006) and Special Funds for Major State Basic Research Projects (2011BAD22B06).

Abstract:

Copper-iron modified bimodal support (M) with different mass fractions of Cu and Fe elements were prepared by an ultrasonic impregnation method. The catalytic performance for higher alcohol syntheses (HAS) was investigated in a fixed-bed flow reactor. Several techniques, including N2 physical adsorption, temperature-programmed reduction/desorption of hydrogen, (H2-TPR/TPD) and X-ray diffraction (XRD) were used to characterize the catalysts. The results indicated that the bimodal pore support was formed by the addition of small-pore silica sol into the macroporous silica gel. Increased amounts of small pore silica sol caused a decrease in pore size in the bimodal carrier. An increase in the Fe/Cu molar ratio facilitated the dispersion of CuO, promoted the reduction of CuO and Fe2O3 on the surface layers, and enhanced the interaction between the copper and iron species as well as the bimodal support inside the large pores. The copper was well-dispersed on the catalyst and the amount of iron carbides formed was high in catalysts with a high Fe/Cu molar ratio. Increasing the Fe/Cu mass ratio promoted the catalytic activity and thus facilitated the synthesis of higher alcohols. When the Fe/Cu molar ratio was increased to 30/20, the CO conversion and the yield of higher alcohols increased to 46% and 0.21 g·mL-1·h-1, respectively. At the same time, the mass ratio of C2+OH/CH3OH reached 1.96.

Key words: Higher alcohols synthesis, Cu-Fe based catalyst, Bimodal pore support, Space-time yield, Selectivity of C2+OH

MSC2000: 

  • O643