Research Of Preparation And Stability Of Highly-dispersed Supported Metal Catalyst In Biomass Catalytic Reaction

Biomass reactions are usually be carried out under harsh reaction conditions such as strong acid/alkaline media,high temperature and pressure,and high water-content,which brings challenges to the design of related catalysts.Highly-dispersed supported catalysts have been a hot research direction in the field of catalysis in recent years,and it is of great significance to understand their deactivation and the mechanism of deactivation under what conditions.This topic focuses on the preparation,characterization and stability test of highly-dispersed supported catalysts.(1)The atomic-dispersed platinum catalysts Pt-DPTZ/CeO2 supported by porous cerium oxide and cerium oxide nanorods were synthesized by the metal-ligand self-assembly method,and it was proved that the method is suitable for both cerium oxide supports.The loading amount is related to the amount of ligand added;the mesoporous alumina-supported platinum catalyst Pt/m-Al2O3 was synthesized by the sol-gel method,and it was proved that the metal loading has a significant effect on the dispersion of the active components.When the loading is 0.2 wt%,a highly-dispersed platinum catalyst with an average diameter of 2 nm was obtained;(2)The possibility of different preparation methods to achieve a highly-dispersed platinum on commercial silicon carbide nanowire supports was explored,and ultrasonic dispersion-assisted wet impregnation was selected.The two synthetic methods,ultrasonic-assisted wet impregnation and equal volume impregnation,can achieve a highly-dispersed platinum catalyst with a diameter of about 3 nm when the loading amounts are 1 wt%and 0.2 wt%respectively;(3)High-temperature hydrothermal and high-temperature steam environment are simulated in a Teflon-lined autoclave.PtDPTZ/CeO2 catalyst which is with good hydrothermal stability was screened out,and GC-MS analysis proved that the catalyst can maintain excellent reaction performance before and after hydrothermal treatment,achieving nearly 100%conversion rate in muconic acid hydrogenation reaction.