Deactivation and regeneration of amorphous Ru-La-B/ZrO2 catalyst for selective hydrogenation of benzene to cyclohexene

The amorphous Ru-La-B/ZrO2 catalyst was prepared and used for the selective hydrogenation of benzene to cyclohexene in the pilot plant. Ru-La-B/ZrO2 showed satisfied activity, selectivity, stability, subside and separate performance. The deactivation reasons for the catalyst running for a long time in the pilot plant were investigated by measuring surface area, pore diameter distribution and ion content in the catalyst as well as in slurry. It was found that the catalyst deactivation was not caused by the plugging of catalyst micropores, decrease in surface area, crystalline grain growth or catalyst poisoning. It was just because that excess Zn2+ and Fe2+ from the reaction slurry were adsorbed on the catalyst. After washing with acid, the activity and selectivity of the catalyst were almost completely recovered. This acid-washing method prolongs the catalyst life and make the catalyst open up a very good prospect in industrialization.