Ru-based catalysts promoted with Mn and Zn were prepared by a co-precipitation method.In liquid-phase hydrogenation of benzene,the Ru-Mn-Zn catalysts exhibited superior catalytic performance to the catalysts promoted with Zn or Mn alone.The optimum Mn/Zn molar ratio was determined to be 0.3.With the addition of 0.5 g NaOH,the Ru-Mn-Zn-0.3 catalyst,which was reduced at 150℃,afforded a cyclohexene selectivity of 81.1%at a benzene conversion of 60.2%at 5 min and a maximum cyclohexene yield of 59.9%at 20 min.Based on characterizations,the excellent performance of Ru-Mn-Zn catalyst was ascribed to the suitable pore structure,the appropriate reducibility and the homogenous chemical environment of the catalyst.