Facet-Dependent Mn Doping on Shaped Co3O4 Crystals for Catalytic Oxidation

Doping other metals is known as a facile strategy to improve the catalytic activity of metal oxide catalysts. However, the doping behavior heavily depends on the surface structure of the host metal oxide, possibly leading to different catalytic properties. Here, Mn was doped onto Co3O4 cubes or octahedra with different facets of (100) and (111), respectively. Mn could be successfully doped into (100) facets, whereas it was excessively accumulated on (111) facets, not incorporating into the lattice. For the simultaneous oxidation of CO, C3H6, and C3H8 with water vapor, Mn-doped Co3O4 cubes showed superior activity because the Mn doping could improve the amount of surface-adsorbed oxygen and the transfer of surface oxygen species. The elaborated Mn doping on Co3O4 cubes could minimize the metal oxide sintering, inducing superior durability. This non-precious-metal oxide catalyst can provide an efficient solution for low-cost automobile exhaust treatment.