Study On The Catalytic Activity Of Ruthenium, Nickel And Copper With Skeletal Structure

A solid knowledge on the preparation, modification and application of skeletal metal catalysts has been accumulated since it was invented in 1925. So far, several kind of skeletal catalysts especially Ni, Cu and Co, have been widely applied in industrial processes like hydrogenation, dehydrogenation and hydration. This thesis studies new synthesis and catalytic application of skeletal Ru, Ni and Cu, which is composed of three parts.The first part is about the study of hydrogenation activity of skeletal Ru(R-Ru). Metal Ru is well known to be very stable with very high melting point. Metal alloy of Ru-Al and M-Ru-Al were prepared by high frequency induction melting furnace and argon arc melting furnace, respectively. The surface morphology and structural characteristics of the alloys were investigated by X-ray diffraction and Scanning Electron Microscope(SEM). Hydrogenations of several compounds were used as probe reactions to test the activity of skeletal Ru. R-Ru was confirmed to be the best catalyst for the hydrogenation of MDA. The reaction mechanism was proved to be a first order consecutive reaction. The reaction factors including temperature, pressure, time, concentration of substrate, solution and water amount as well as the lifetime of the catalysts were investigated. Under the optimal conditions, the conversion of reactant and the yield of H₁2MDA are both as high as 100% with content of trans-trans isomer being lower than 10%. High stereoselectivity is a very important feature of the R-Ru catalyst.The second part is about the study of modified skeletal Ni. Though R-Ni has been widely used in commercial hydrogenation process. It is still urgent to develop more active R-Ni catalyst. Skeletal Ni was found to be able to meet the special requirements of several hydrogenation reaction by controlling the modification components of alloy precursor as well as by optimizing reaction parameters. The hydrogenation of biphenyl to cyclohexylbenzene over modified skeletal Ni was studied. We obtained the yield of 99.4% by one-step reaction, which was the highest result in the scope of our literature study. The mild reaction conditions, low production cost and extremely high valued product indicate great potential for further industrial application.The last part is about the study of skeletal Cu in hydration of ethylene oxide . Skeletal Cu was known to be active for hydration of nitrile compounds (especailly acrylonitrile) to form corresponding amide. We found skeletal Cu is a good catalyst for selective hydration of ethylene oxide to produce glycol under temperature of 90¹10℃ and molar ratio ofwater to ethylene oxide of 8-13. The selectivity of ethylene glycol is between 87%-90% under this conditions. This research is significant and meaningful from the point of theory and practice. The research will go on in our lab.