Study Of Catalytic Performance CO Oxidation On Au Supported On Three-dimensionally Ordered Macroporous CeO₂ Catalysts

Three-dimensionally ordered macroporous(3DOM)materials have attracted the attention of many researchers in the field of catalysis due to their regular pores and ordered periodic structure.A commonly used method for preparing three-dimensionally ordered macroporous materials is polymethyl methacrylate(PMMA)template method.It mainly includes four steps:The monodisperse microspheres are synthesized by heating reaction of methyl methacrylate(MMA),and the microspheres are arranged in an orderly manner by heating and evaporation to obtain the template;the template is completely soaked in the precursor solution of the desired target product to make the precursor fully fill in the gap of the template;remove excess precursor and dry;remove the template to get the desired 3DOM product.Cerium oxide is an important oxide in heterogeneous catalysis,because of its oxygen deficiency,storage and release of oxygen.The strong ability and easy realization of trivalent cerium and tetravalent cerium conversion make it have important application prospects in the field of industrial catalysts.Moreover,cerium oxide itself is active,and oxygen vacancies on the surface will also promote the catalytic oxidation of CO[1].The precious metals that catalyze the oxidation of CO are mainly Au,Ag Pd,Pt,etc.The morphology of cerium oxide as a carrier supporting precious metals for carbon monoxide oxidation reactions also shows significant catalytic effects.The three-dimensionally ordered macroporous material has high specific surface area and the reactant molecules are easy to mass transfer,and have high thermal stability and chemical stability.The three-dimensional ordered macroporous cerium material supported precious metal catalyst is expected to show excellent catalytic performance for the CO oxidation reaction.In this paper,PMMA was used as the template,and Ce(NO3)3·6H2O and Zr OCl2·8H2O were used as precursors to prepare three-dimensionally ordered macroporous cerium oxide(3DOMCeO2)and three-dimensionally ordered macroporous ceria-zirconia solid solutions(3DOMCeZrO2).Cerium oxide nanorod(CeO2rod)was prepared by hydrothermal method.Finally,gold catalysts were supported by the same volume impregnation method:Au/3DOMCeO2,Au/CeO2rod,Au/3DOMCeZrO2.The catalyst was characterized by XRD,BET,SEM,TEM,H2-TPR,XPS,Raman and other methods,and its catalytic activity for CO oxidation of atmospheric pollutants was evaluated.Compared with the catalyst Au/CeO2rod,Au/3DOMCeO2 have the most Ce3+and Au+ content on the surface and exhibits better activity.Compared with Au/3DOMCeO2,Au/3DOMCeZrO2 catalyst has higher thermal stability and catalytic activity.