Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (04): 799-805.doi: 10.3866/PKU.WHXB201302052

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Fe3O4 Modified Alumina Supported Ruthenium Catalyst for Novel In-situ Liquid Phase Catalytic Hydrogenation

CHEN Ao-Ang, XU Xiang-Sheng, HUA Yan-Xiang, GU Hui-Zi, YAN Xin-Huan   

  1. State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China
  • Received:2012-12-18 Revised:2013-01-30 Published:2013-03-25
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20676124, 21076197), Natural Science Foundation of Zhejiang Province, China (Y4090440), and Qianjiang Talent Program of Zhejiang Province, China (2010R10038).

Abstract:

Ru-Fe3O4/γ-Al2O3 was synthesized by stepwise impregnation method and applied to the in-situ liquid phase selective hydrogenation of 3,4-dichloronitrobenzene (3,4-DCNB). The nanoparticle size and distribution, metallic crystalline constitution, surface structure parameters, and adsorption species were systematically characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, N2 adsorption-desorption (BET), and X-ray photoelectron spectroscopy (XPS). The Ru-Fe3O4/γ-Al2O3 catalyst was investigated using the in-situ liquid phase hydrogenation of 3,4-DCNB as probe reaction, the effect of different reaction conditions and different synthetic factors on the catalytic properties was studied. Experimental results showed that the catalytic properties of the Ru-Fe3O4/γ-Al2O3 catalyst were significantly influenced by its Fe3O4 content, under the optimum condition of 473 K, 3.0 MPa, 2% (w) 3,4-DCNB concentration with 75% ethanol and 25% water, the Ru-Fe3O4/γ-Al2O3 catalyst with Ru and Fe mass fractions of 2% and 6% exhibited the highest activity and stability, with 100% conversion of 3,4-DCNB, 96.4% selectivity of 3,4-dichloroaniline (3,4-DCAN), and this catalyst could be stabilized for more than 200 h. The main reason for the deactivation of the catalyst is CO coverage on active centers, and the poisoning-deactivated catalysts were regenerated by water-gasshift (WGS) reaction and Fischer-Tropsch synthesis (FTS), which employ Fe3O4 modified Ru/Al2O3 as catalyst due to its high efficiency of CO transformation. Carbon deposition on the catalyst surface is the reason second only to carbon monoxide poisoning, and this could be removed through calcination. Crystalline phase change and nanoparticles aggregation may cause partial deactivation, and investigation of the mechanism and catalyst regeneration are in progress.

Key words: Ruthenium, Iron oxide, Catalytic stability, 3,4-Dichloronitrobenzene, In-situ liquid phase hydrogenation, CO poisoning deactivation

MSC2000: 

  • O643