The Preparation Of The Cu/ZrO₂ Catalyst For Dehydrogenation Of Cyclohexanol And Research Of The Reactivities

Cyclohexanone is a basilic fine chemical material,which is used as the key intermediate for synthesis of caprolactam,adipic acid and some other kinds of pharmaceuticals.Besides,cyclohexanone is also widely used as the solvent of oil paint, nitrocellulose and so on,because of its admirable property of diffluence and low volatility. It plays an important role in the fine chemical and petrochemical industries.There are two methods to make cyclohexanone from cyclohexanol.Frist,chromic acid catalytic oxygenizes cyclohexanol to create cyclohexanone.Second,use the way of catalytic dehydrogenation to transform cyclohexanol to cyclohexanone.The process of catalytic dehydrogenation for cyclohexanol to cyclohexanone has many advantages such as fewer side reaction,easier operation,higher yield and more safe.Therefore,it is very common to use the method of dehydrogenation of cyclohexanol to cyclohexanone in industrial production.However,to empolder a serials of dehydrogenation catalyst with high efficiency and economical value is the pivotal technique.A new type of catalyst Cu/ZrO₂ in the paper was prepared from the solution of Cu(NO₃)₂,ZrOCl₂·3H₂O by using NaOH as the precipitant through co-precipitation method.On the basis of it,we have detected the influence of catalyst's preparation condition on the dehydrogenation activity of cyclohexanol.Through orthogonal experiment combined with single factor experiment,we have got the optimized preparation condition for the catalyst[n(Zr):n(Cu)=2:1,the initial C(Zr)=0.2mol·L^-1, roasting time=5h,roasting temperature=500℃and the end point of titration pH=12.5]. The results show that,using the catalyst prepared at the optimized condition in the high pressure reaction kettle with reduction temperature 240℃,the yield of cyclohexanone can be reached to 76%and the selectivity is nearly 100%.The reaction process for dehydrogenation of cyclohexanol was studied,to detecting the influence of reaction temperature,reaction time and material composing on the yield and selectivity of the dehydrogenation.Under the same experimental condition,the new catalyst was compared with the DH₀₂₁ catalyst which is already used in industry.It can be concluded that the new cuprum catalyst is much more better than the industrial used catalyst in production yield and selectivity.Combined with TG,TPR,BET,XRD,SEM etc.catalyst token means,the two kinds of catalysts were also compared.