Facile synthesis of three-dimensionally ordered macroporous LaFeO3-supported gold nanoparticle catalysts with high catalytic activity and stability for soot combustion

Abstract

A strategy for the facile synthesis of three-dimensionally ordered macroporous (3DOM) LaFeO3-supported gold nanoparticle catalysts is reported, namely in situ colloidal crystal template (CCT) method. The synthetic process involving in three steps are listed in detail, for example, the synthesis of monodisperse polymethyl methacrylate (PMMA) microspheres accompanied with polyelectrolyte brushes ([NH2]+·Cl−, PEBs), the preparation and assembling of CCT with spherical Au/PMMA compound, and the formation of 3DOM LaFeO3-supported gold catalysts via calcination to remove the CCT. All the catalysts have well-defined 3DOM structures, and gold nanoparticles are uniformly dispersed on the inner wall of 3DOM LaFeO3 support. 3DOM structure can improve the contact efficiency between soot particle and catalyst, and the strong metal (Au)-oxides (LaFeO3) interaction provides the active sites for activation of O2. 3DOM Aun/LaFeO3 catalysts obtained by in situ CCT method show high catalytic activity and stability for diesel soot oxidation. It suggests that 3DOM Aun/LaFeO3 catalysts are excellent systems for catalytic oxidation of solid soot particle, and the design concept and facile synthesis method of 3DOM oxide-supported Au nanoparticle catalysts can be extended to other metal/oxide compositions.