Herein, Co₃O₄ decorated manganese oxide octahedral molecular sieve (OMS-2) catalysts with cactus-like nanorod morphology are in situ constructed on industrial cordierite monoliths for soot combustion. The specific structure of the catalysts provides sufficient macroporous space to improve the soot-catalyst contact efficiency. Compared with traditional powder-coated catalysts, the consumption of the as-synthesized catalyst is saved by ∼13 times with the same thickness, and the contact area is enlarged by ∼4 times with the same weight. Our findings show that the interface interaction between Co₃O₄ and OMS-2 promotes the generation of oxygen vacancies. The isotopic ¹⁸O₂ results reveal that the number of active sites for soot combustion on the Co₃O₄ modified catalyst is 3 times larger than that on OMS-2 alone. Additionally, this interaction accelerates the activation of gaseous oxygen, and especially enhances the intrinsic activity, as well. The above advantages improve the apparent soot oxidation activity by ∼11 times.