A novel amorphous alloy Ru–La–B/ZrO2 catalyst with high activity and selectivity for benzene selective hydrogenation

A novel amorphous alloy Ru–La–B/ZrO2 catalyst with high activity and good selectivity to cyclohexene was prepared by a chemical reduction method. Various characterizations on the catalyst were carried out by means of XRD, TEM-SAED, XPS, ICP-AES, PSD and N2-physisorption. The performance of the catalysts was examined under pilot conditions. The results showed that the bulk composition of the catalyst was Ru18.14La0.08B18.86/ZrO2, that almost all ruthenium species existed in the elemental state, and that La existed in the La3+ state. The most probable pore diameter is about 32 nm, and the most probable particle size was ca. 5 μm. The performance and stability of the Ru–La–B/ZrO2 catalyst is superior to that of the Ru–B/ZrO2 due to the promoting effect of La. The slurry comprising zirconia and zinc sulfate is very important for benzene selective hydrogenation over the Ru–La–B/ZrO2 catalysts in order to obtain high yield to cyclohexene. Under the pilot conditions, the performance of the Ru–La–B/ZrO2 catalysts can be improved by changing the pH value of the slurry and by adding zirconia into the slurry.