Hydrogenolysis Of Glycerol On Bimetallic PdCu/solid-base Catalysts

The declining reserves of petroleum and natural gas and environmental problemscaused by their use have become two major bottlenecks of sustainable development ofthe society and economy.This two issues have in turn greatly promoted the researchand development of the renewable biomass resources. As a major byproduct ofbiodiesel production, glycerol is a kind of very ideal renewable biomass resource. Thehydrogenolysis of glycerol for the synthesis of propylene glycol and ethylene glycolto reuse the growing supply of glycerol can improve the economic efficiency andtherefore has great research value. The present thesis focuses on the development ofsolid-base catalyst in the production of valuable commodity chemicals frombio-glycerol through hydrogenolysis.The copper-based supported catalysts by different carriers were prepared, and theeffect of supports on the catalytic performance was investigated. The results showedthat alumina supported catalysts had a better catalytic activity. At the beginning of thework, we intended to prepare a Cucatalyst loaded on solid baseKF/Al2O3via thermaldecomposition of Cu-KF/γ-Al2O3, and this bifunctional catalyst was used in glycerolhydrogenolysis to1,2-propanediol (1,2-PDO). However, Cu-KF/γ-Al2O3exhibitedsuperior catalytic performances in glycerol conversion, the selectivity towards1,2-PDO is relatively too low.It was found that the addition small amount of Pd couldmake Cu-KF/γ-Al2O3catalyst more active in current reaction. The PdCu-KF/γ-Al2O3catalyst exhibited a catalytic selectivity to1,2-PDO of about98.3%with a glycerolconversion of nearly100%at200oC (2.5MPa initial H2pressure,20h) due tosuccessfully suppressing the cleavage of the C-C bonds in glycerol. The reusability ofthe catalyst was tested by conducting five runs with the same catalyst and it wasfound that the conversion and selectivity decreased slightly after five reuses.X-raydiffraction (XRD), transmission electron microscopy (TEM), X-Ray PhotoelectronSpectroscopy (XPS) and desorption of CO2/NH3(CO2/NH3-TPD) characterizationsthe properties of the catalysts.