560 / 2019-01-16 22:42:19

Preparation of Core-Shell Structure Fe3O4@SiO2@CuZnAl-O Magnetic Catalyst and Study on Catalytic Liquefaction in Supercritical Methanol

Core-shell structure; Magnetism; Fe3O4@SiO2@CuZnAl-O; Lignin; Catalytic liquefaction

全体主题 > 节能、联产、热泵

The Fe3O4@SiO2@CuZnAl-LDH catalyst precursor with different mole ratio Cu2+/Zn2+ were prepared through co-precipitation method. The magnetic core-shell Cu-Zn-Al complex oxide Fe3O4@SiO2@CuZnAl-O catalyst was obtained by calcining the precursor at 500℃ in nitrogen atmosphere and the catalyst was used to catalyze liquefaction of lignin in supercritical methanol. The structure and magnetic properties of the prepared Fe3O4@SiO2@CuZnAl-O catalyst were characterized by X-ray diffraction(XRD)，scanning electron microscopy (SEM),transmission electron microscopy(TEM)，N2 adsorption/desorption, specific surface area analysis(BET) and magnetic performance analysis. The effect of catalyst on lignin liquefaction products in supercritical methanol with different time and temperature was investigated. The results showed that the catalyst structured the nanometer microspheres and formed the core-shell structure, covering a layer of Cu-Zn-Al-O on the surface of the microspheres. The saturated magnetization of the catalyst was 36.1emu/g. When the molar ratio is Cu/Zn=1.2/4.8, the specific surface area of the catalyst was 142.8m2/g, and the liquefaction conversion was the highest(66.5%) in the process. Lignin liquefaction products contained phenols, ketones, hydrocarbons, and benzene. The increasing reaction time and reaction temperature will make the products more complex, and the phenolic substances showed a decreasing tendency, the ketones accounted for more than 50%.