Synthesis And Properties Of Efficient Nano Cobalt-based And Copper-based Catalyst In The Hydrogenation Of Diol Reaction

1,2-propanediol(1,2-PDO), used as high value-added specialty chemical intermediate, widely used as solvent, hygroscopic agent, lubricant and antifreeze in pharmaceuticals, food and cosmetics manufacturing. At present,1,2-PDO is mainly produced from the hydration of corresponding epoxy alkanes, which are commonly derived from the petrochemical approach. This approach is costly and will contaminate the environment. As crude oil resource shrinks and derivatives prices soaring, much attention has been devoted to convert bio-renewable feedstock to bio-materials, since it is sustainable, renewable and carbon-neutral process. Large amount of glycerol was obtained from biomass via transformation of oils, thus synthesis of 1,2-PDO from bio-glycerol attracts more and more interest. In this work catalytic hydrogeolysis of glycerol to diols on CoAl alloy catalyst under mild conditions has been studied in details. we have demonstrated that a facile and efficient one pot catalytic process of glycerol to value added 1,2-PDO and EG. Through characterizations, the reason of stability of the alloy catalyst was also investigated.Ethylene glycerol (EG), was an important chemical widely used in manufacture of plastic, rubber, adhesive, polyester fiber, antifreeze, polyester resin, nonionic surfactant, cosmetics and explosive. Traditionally, EG was synthesized from ethylene oxide which is excessively dependent on the petroleum resource. Therefore, exploitation of resourceful coal and natural gas and develop Cl chemical have great strategic and economic importance. Indirect synthesis of EG from syngas via the coupling of CO to obtain oxalates and then the oxalates was hydrogenation to EG, the key step was the latter. Mesoporous materials possess large pore, high surface area and high thermo-stability, was widely used as support in catalytic reactions. Mesoporous materials could improve the distribution and stability of active sites, result in enhanced catalytic activity and selectivity to the target products. In this paper B modified mesoporous materials to support Cu catalyst was used at high LHSV with decent catalytic performance.Hydrogenolysis of glycerol over CoAl alloy catalyst to diols (1,2-PDO and EG) as well as hydrogenation of DMO on the Fe modified Cu catalyst was fully studied. The effects of synthesis method of the catalyst and reaction conditions on the catalytic performance was focused in this paper. Highly stable CoAl alloy catalyst was first used in the hydrogenolysis of glycerol,100% glycerol conversion and 66.5% selectivity to the liquid products could be obtained over the alloy catalyst without any pretreatment.90.6% conversion of glycerol with 51.9% selectivity to liquid products maintained when the catalyst was reused five times. Characterization of the alloy before and after reaction showed that the surface area of the catalyst was greatly enhanced from 14 cm2/g to 80 m2/g because of Al was leached from the alloy and only a small amount of Co2Al9 crystalline of the alloy was maintained after the reaction. Whereas Al2O3 was formed from Al leached from the alloy, which can serve as a support to disperse active Co. And the acid site of the Al2O3 could make the dehydrogenation of glycerol to acetol more easily. With a smart device in the autoclave liquid products could separated from the solid catalyst automatically, thus much energy could be saved, Further improvements can be expected which offered excellent prospects for a fully integrated process, even opened a route to practical applications.The influence of iron introduction on the performance of 10 wt.% Cu/SiO2 catalysts for the catalytic hydrogenation of dimethyloxalate was systematically investigated. It is shown that the iron loading and iron source have great effect on the catalytic behaviors of the catalyst. Characterization methods including X-ray diffraction, H2-temperature-programmed reduction, and X-ray photoelectron spectroscopy were carried out to elucidate the structure evolution of the catalyst with the introduction of iron. Experimental results showed that the Fe2O3-modified catalyst prepared via the ammonia-evaporation-induced synthesis method exhibited the highest conversion and ethylene glycol selectivity because of the higher metallic copper surface area and copper dispersion. The optimum Fe/Si mole ratio, which strongly affects the surface composition of the catalyst, was found to be 1/3.100% DMO conversion and 92% EG selectivity could be obtained over the Cu/c-Fe2O3/SiO2(1/3) catalyst under 1.5 h-1 liquid hour space velocity, which is great enhanced compared with catalyst without Fe introduction.