Preparation and Modifiable Character of a Novel Amorphous Catalyst Ru-Fe-B/ZrO_2 for the Selective Hydrogenation of Benzene to Cyclohexene

A novel nano-amorphous Ru-Fe-B/ZrO_2 catalyst was prepared by the chemical reduction method and showed high activity and selectivity in the selective hydrogenation of benzene to cyclohexene.The catalyst was characterized by transmission electron microscopy,selected-area electron diffraction,X-ray diffraction,and N2 adsorption.The modifiable character of the activity and selectivity of the catalyst and the effects of NaBH4 concentration and pH of the filtrate on the catalyst performance were investigated.The results showed that over this catalyst the selectivity for cyclohexene reached 80% at 54% of benzene conversion.Moreover,the selectivity decreased slowly with the increase of benzene conversion.The activity and selectivity of the catalyst could be adjusted through adding acid or alkali to the reaction system.The catalyst preparation and properties could be repeated.It was concluded that the nanometer scale and amorphous structure of the catalyst were the main factors for its high activity and selectivity for the selective hydrogenation of benzene to cyclohexene.