A ternary oxide catalyst composed of CuO-Co3O4-CeO2 (CCC) has great potential for automotive exhaust treatment due to its excellent CO oxidation activity and high resistance against hydrocarbon inhibition. However, current CCC catalyst exhibits significantly lower hydrocarbon oxidation activity comparing to CO oxidation, and deactivation occurs severely after hydrothermal aging. Here, we show that a Mn-doped CCC (CCCM) catalyst exhibits enhanced activity and durability for C3H6 oxidation, while maintaining the high activity for CO oxidation. The Mn-doping prevented sintering and phase separation of the Co3O4 phase even after hydrothermal aging at 750 degrees C for 25 h. The Mn was selectively doped into Co3O4 by substituting Co3+ octahedral sites in the Co3O4 spinel structure. The presence of Mn with a larger cation radius induced lattice expansion of the Co3O4 phase with more surface active oxygen. This strategy can provide a facile way to develop better non-PGM catalysts for emission control.