Preparation And Analyst Of Bifunctional Copper Catalysts For Transfer Dehydrogenation Of Primary Aliphatic Alcohols And Study Of Basic Catalysis

The oxidation of alcohols to carbonyl compounds is an essential functional group transformation in organic synthesis. An interesting alternative to aerobic conditions is to introduce a readily available and unsaturated organic molecule as the hydrogen acceptor instead of using oxygen, thus overcoming safety concerns linked with flammable solvents. Cu catalysts showed high activities in transfer dehydrogenation of secondary aliphatic alcohols using styrene as the hydrogen acceptor. Hydrotalcite-supported Cu particles effectively catalyzed oxidant-free dehydrogenation of secondary aliphatic and benzylic alcohols. Basic metal oxides supported copper catalysts were demonstrated remarkably activities in alcohol dehydrogenation. Even though countless efforts had been made for improving dehydrogenated primary aliphatic alcohols, it is still an appealing challenge to advance it.A serise of catalysts for the transfor dehydrogenation of primary aliphatic alcohols has been developed. These composites have been obtained by coprecipitating Mg(NO3)2·6H2O, Al(NO3)3·9H2O and Ca(NO3)2·4H2O (in chapter Ⅲ) Mg(NO3)2·6H2O, Al(NO3)3·9H2O and La(NO3)3·6H2O (in chapter Ⅳ) to form hydrotalcite-like precursors which were then calcined to made mixed oxides catalysts supports. Copper was loaded through impregnation. The typical patterns of XRD of Layered hydroxides shows that target projects have been successfully synthesized. The basic properties of the target projects were evaluated qualitatively using CO2in situ FTIR and quantitatively by TPD of CO2. Both techniques indicated the presence of strong basic sites. The transfer dehydrogenation of primary aliphatic alcohols reaction under liquid phrases (423K, N2atmosphere), which is known to involve strong basic sites, was used to evaluate the catalytic activity and selectivity of the target projects supported catalysts. Copper in the size of around11-12nm was more active in conversion. Yields of aldehydes increase with density and variety of strong basic sites of the catalyst.