Process for the preparation of a mixture of cyclohexanone and cyclohexanol

A process for the preparation of mixtures of cyclohexanone and cyclohexanol in predetermined ratios to one another in the range from 30:70 to 98:2 by hydrogenation of phenol with hydrogen in the gas phase at 150 to 250.degree. C. under 0.8 to 8 bar over a supported palladium catalyst, wherein, for initial activation and for regeneration after use, the catalyst is subjected to an oxygen pretreatment, if appropriate, and then a hydrogen treatment in each case under 0.8 to 8 bar, the following time/temperature conditions being applied to establish the predetermined ratio:

• a) Cyclohexanone:
• cyclohexanol=85.15 to 98.2
• a1) for initial activation, no O.sub.2 pretreatment and H.sub.2 treatment for 50-10 hours at 300.degree.-500.degree. C.;
• a2) for regeneration, O.sub.2 pretreatment for 30-0.5 hours at 220.degree.-380.degree. C. and H.sub.2 treatment for 2-6 hours at 150.degree.-250.degree. C.;
• b) Cyclohexanone:cyclohexanol=30:70 to below 85:15
• b1) for initial activation, O.sub.2 pretreatment for 40-3 hours at 250.degree.-500.degree. C. and H.sub.2 treatment for 2-6 hours at 150.degree.-250.degree. C.;
• b2) for regeneration, O.sub.2 pretreatment for 30-0.5 hours at 380.degree.-600.degree. C. and H.sub.2 treatment for 2-6 hours at 150.degree.-250.degree. C.