Study on Ceria-based and Cobalt-based Hybrid Structures Controlled Synthesis and Their Catalytic Performance

Author:Wang Shu Ping

Supervisor:yang yan zuo


Degree Year:2019





An important research direction in nanoparticles synthesis is the expansion from singlecomponent nanoparticles to multicomponent hybrid nanostructures with discrete domains of different materials arranged in a controlled fashion.The advantages of multicomponent structures lie in three aspects.The first is to realize multifunctionality;different functionalities can be combined in one single nanoparticles.The second advantage is in providing novel functions not available in single-component materials or structures.The third advantage is in achieving enhanced properties due to the couplings between the different components.In fact,because many physical and chemical properties have critical length scales on the order of nanometres,the intimate contact between the nanocomponents in hybrid nanoparticles should allow strong interactions between these components and a possible rational modulation of the physical and chemical properties of each individual component.Eventually,the hybrid stuctures may have potential applications in diverse fields,such as medical diagnostics and treatment,optical and electronic applications,energy storage and so on.The detailed information of the paper is summarized as follows:1.We have developed a one-pot strategy towards the synthesis of core-satellite structures based on the fractional precipitation rule.Benefiting from the multiple active contacts between the "core" and "satellite" materials,these structures show high catalytic activity in CO oxidation reaction.This general synthetic method provides an alternative in design of hybrid suprastructures2.Two-dimensional(2D)materials enabled the creation of hybrid heterostructures with a variety of properties.Here,inspired by the "core-shell" structures,we report the synthesis of a hierarchical structure based on the growth of 2D Mn/Ni(OH)x sheets on the CeO2 spheres,so called sheet-on-sphere heterostructures.The supported 2D sheets serve as robust support for the immobilization of metal nanoparticles.The as-formed hetero structures offer a robust catalyst system and display excellent catalytic performances toward the 4-nitrophenol reduction in liquid-phase and CO oxidation in gas phase.Moreover,the present catalyst exhibits excellent durability and reusability attributed to the compartmentalized active species against sintering.3.We have developed a seeded strategy for preparing two kinds of cobalt/nickel carbonate hydroxides complex hierarchical heterostructures:plates-on-rods and rods-on-plates structures.The electrocatalytic properties of these two structures were evaluated.CO and NO are the main pollutants of automobile exhaust gas,and the above-mentioned multicomponent hybrid structures without noble metal is used in the 2CO+2NO→2CO2+N2 reaction.We can fabricate a suitable and inexpensive catalyst by taking advantage of multifunctional multicomponent hybrid structures.