Studies On The Catalytic Hydrogenation Of Cyclohexanone And Research On The Preparation Method Of The Catalysts

The reduction of aldehydes and ketones to corresponding methylene compoundsis one of the most important organic transformations which is widely applied inenergy industries, pharmaceutical industries, fine chemical industries and so on.Wolff-Kishner-Huang Reaction and Clemmensen Reduction are the traditionalmethod in industry. However, there is some defects in both of them. So, a reduction ofcyclohexanone as the template of aliphatic ketones via catalytic hydrogenation wasgiven with the purpose of establishing a green process for the reduction of thealiphatic ketones.1. A series of catalysts were examined. As a result, Ni/H-ZSM-5-γ-Al2O3waspicked out for the high activity. The conversion is as much as97.3%and theselectivity of the cyclohexane is86.3%which illustrates that the addition of the binderagent do affect the reduction. The optimum reaction conditions are: reactiontemperature is160℃，the H2pressure is2.0MPa, the flow rate is0.20Ml/min(10wt%,1,4-dioxane). The running life of the catalyst is over100h.2. The preparation method of the catalysts was studied with the comparison ofimpregnation and co-precipitation-kneading methods. A sharply acidic and texturalchange was observed on the catalysts prepared by different method, while the metalactive phase structure was almost the same.3. Alkaline treatment of the support could dramatically improve the performanceof this catalyst, while conversion of cyclcohexanone and the selectivity towardscyclohexane reached to99.8%and99.0%respectively with a2h of alkaline treatment.A structure of mesoporous was detected by TEM which illustrates the increasing ofthe activity of the catalyst.