Three-dimensionally ordered macroporous MnSmOx composite oxides for propane combustion: Modification effect of Sm dopant

Abstract Three-dimensionally macroporous (3DOM) MnSmOx composite oxides were prepared via a hard-template method and utilized as catalytic materials for propane combustion. The modification effect of samarium dopant on both their physicochemical and catalytic properties were systematically investigated by means of characterization techniques and experimental approaches. Characterization results revealed that the increasing addition of samarium into MnOx favored the formation of 3DOM structure, and the doping of samarium induced the crystalline phase transformation of Mn2O3 into Mn3O4, concurrently leading to the remarkable improvement of redox ability and surface oxygen mobility as well as higher abundance of surface labile oxygen species. All above-mentioned properties were demonstrated to be the major determinants for boosting the propane combustion performances of Sm-doped catalysts. Among all, the 3DOM Mn0.85Sm0.15Ox (denoted as M0.85S0.15) exhibited the optimum catalytic activity and good regeneration capacity under humid conditions. Additionally, the comparative in situ DRIFTs analysis over M0.85S0.15 and the bulk counterpart (denoted as B-M0.85S0.15) emphasized the superiority of 3DOM architecture on promoting the surface adsorption and oxidation of propane molecules.