The preparation and activity of nickel-molybdenum coal hydrogenation catalysts

Imperial Users onl

Hydrogenation of benzene to cyclohexene on an unsupported ruthenium catalyst: Effect of poisons

The influence of poisoning of ruthenium catalysing the selective hydrogenation of benzene to cyclohexene has been studied. Both the yield of cyclohexene and the rate of hydrogenation are greatly affected by the degree of poisoning (e.g. FeSO4, FeCl3, TiCl3 and oxygen), and may also be optimised. A reproducible catalyst has been prepared by precipitating the catalyst precursor, as the hydroxide, in a glass vessel at 353 K without influence of corrosion products from the reactor material. The influence of the hydrogen pressure on activity has also been investigated. An optimum pressure for maximum yield of cyclohexene was obtained and a rate expression was formulated which could account for reaction orders varying with hydrogen pressure