Research development of hydrogenation of benzene to cyclohexene

The research and development of catalysts for the partial hydrogenation of benzene to cyclohexene is very important. In this paper, the various zinc-containing ruthenium catalysts for this reaction, the preparation of the catalysts and effects of supports are reviewed in detail. Modified catalysts containing salt of alk - earth hydroxides or transition - metal sulfates exhibit excellent high cyclohexene selectivity and yield. Water, organic compounds such as phenylcarbinol or 1,4 - butanediol and other additives are beneficial to this reaction. The methods of regeneration and preventing deactivation of catalysts are reviewed briefly. The influence of temperature, hydrogen pressure and contents of active component in catalysts are discussed.