Selective Hydrogenation of Benzene to Cyclohexene over the Nano-Sized Ru-Zn Catalyst Modified by Arabic Gum

A nano-sized Ru-Zn catalyst was prepared by a co-precipitation method and the effect of arabic gum modification on the performance of Ru-Zn catalysts was investigated. The catalysts were characterized by X-ray diffraction (XRD), transimission electron microscopy (TEM), N-2 physisorption, X-ray photoelectron spectroscopy (XPS), and X-ray fluorescence (XRF). It was found that the dosage of arabic gum could tune the particle size of the Ru-Zn catalysts. The maximum cyclohexene yield showed a volcanic-type variation tendency with the particle size of Ru-Zn catalysts increasing. When the mass ratio of arabic gum to RuCl3 center dot xH(2)O was 0.033, a Ru-Zn catalyst with a optimum particle size of 4.0 nm was obtained, and a maximum cyclohexene yield of 59.6% was achieved. Moreover, the catalyst exhibited the excellent reusability.