Study On The Catalytic Performance Of Cu-based Catalysts For Hydrogenolysis Of MIBK

Methyl isobutyl carbinol is a good medium boiling point solvent and an important chemical material which has widely use in the chamical field. For example, it was be use in pesticides, pharmaceuticals, adhesives, synthetic resins, and mineral processing. The demand of MIBC has been increasing with the rapid development of the automobile industry, chemical industry and pharmaceutical industry. So MIBC has a large market potential. Isopropylidene acetone (MO) was the intermediate product of produce of MIBK by acetone three-step,and MIBC was the by-products of MO hydrogenation.The preparation of MIBK from the hydrogenation of Mo was greatly affected and restricted by the development of the producing of MIBK by one-step hydrogenation of acetone. Direct hydrogenation of MIBK was the main method to produce MIBC due to the simple process. Therefore, it is a very important subject to research and development new hydrogenation catalysts which could improve the product quality, make the production costs lower, and reduce the pollution of the environment.Copper-based catalysts were widely used in hydrogenation reactions, dehydrogenation reactions and oxidation reactions, owning to the good performance of Low-temperature catalytic, and the cheap price, but the copper-based catalyst applied in the hydrogenation of MIBC has not been reported.The purpose of this thesis is to synthesis copper-based catalyst which have excellent catalytic activity in methyl isobutyl ketone (MIBK) hydrogenation reaction. We use different preparation methods to synthesize copper-based catalyst and evaluated in MIBK hydrogenation reaction, study the activity of these catalysts in the reaction in details.and the catalyst samples were characterized to examine its internal structure and surface properties, and we try to correlate the Characterization results and reaction results. Try to provide useful information and theoretical basis to better understand the law of carbonyl activation, mechanism of catalytic hydrogenation, and research of the selective hydrogenation catalyst of ketones. The main contents are as follows:1. A series of CuO-ZnO catalysts which has a good catalytic activity for the hydrogenation of MIBK were synthesized by co-precipitation methods, and we investigated the catalyst performance affected by the composition of catalyst, reaction conditions, synthesis conditions and other factors. It was found that the conversion of MIBK could reach 99.7%, and the selectivity of MIBC was more than 99% when the CuO-ZnO catalyst with the molar ratio of copper and zinc was 1:3 was used under the conditions of that the temperature was 220℃, the pressure was 4Mp, the space velocity 0.6 h-1, and the ratio of hydrogen and ester was 15. We alsor investigated that the catalytic properties was affected by the conditions of the preparation of the catalyst. The CuO-ZnO catalyst show a better Catalytic performance for the hydrogenation of MIBK under the conditions of that Cu(NO3)2 was used as precursor, Na2CO3 was used as precipitant, synthesis temperature was 80℃, calcination at 450℃under air, owing to that the miscibility between copper and zinc was strong Above on, we believe that the reasons for the catalyst have a good catalytic performance is that the smaller particle size of copper species, the higher dispersion of copper species,and better miscibility between the copper and zinc.2. The copper zinc aluminum zirconium catalyst systems were used for the hydrogenation of MIBK. We investigated that the effects of different copper content,the copper content was 40% show the best activity, And we also investigated that the effects of calcination temperature of the catalyst, the calcination temperature was 600℃and 700℃show the similar activity, but significantly higher than the calcination temperature was 400℃and500℃. Finally, we investigated that the effects of the dispersant add to the catalysts, when the dispersant was P123, the activity was better. Combination with the characterization of TPR and XRD, wo found that CuAl2O4 species has a great influence on the reaction performance, an appropriate amount of CuAl2O4 species exist in the catalyst sample, was benefit to the catalyst to show the best catalytic activity3. We applied two types of preparation methods to synthesis of copper silicon catalyst CuO/SiO2 and CuO/SBA-15, and applied in MIBK hydrogenation reaction. The CuO/SBA-15 catalysts show a better activity. The materials was Characterized by a series of characterization test, and evaluation results were associated with the activity of the MIBK Hydrogenation reaction. We found that the highly dispersed copper species was useful to improve the activity.And we also try to synthesize CuO/SBA-15 catalytic materials by one step hydrothermal synthesis, and the material was showed a high catalytic activity in MIBK hydrogenation reaction, the conversion of MIBK was significantly higher than the CuO/SBA-15 material synthesized by Ion exchange, by the characterization of FTIR, BET, XRD,we confirmed that the copper species were dmbed into the skeleton of silica, So copper species have stronger effect with the carrier, good dispersion,difficult to gather, and maintain the number of active centers and the surface area.