Developing highly efficient and robust catalysts for low-temperature CO oxidation is essential for CO abatement in sintering flue gas.CuO-Co3O4 catalysts incorporated with transition metal oxides (TMOs) of CeO2, ZrO2, NiO or Fe2O3 were synthesized using the sol-gel method.The crystalline structure, morphol., electronic structure, surface active sites and redox properties of the composite catalysts were characterized by X-ray diffraction (XRD), field-emission SEM (FESEM), energy-dispersive X-ray spectroscopy (EDX), XPS, CO temperature-programmed desorption (CO-TPD), H2 temperature-programmed reduction (H2-TPR), and O2 temperature-programmed oxidation (O2-TPO).The influence of incorporating TMO on CO oxidation performance of the composite catalysts was thoroughly investigated.Results indicated that incorporating CeO2 and ZrO2 enhanced the CO oxidation activity of CuO-Co3O4 significantly, achieving notably low T100 temperatures of 134 °C and 150°C.The desired CuO-Co3O4-CeO2 and CuO-Co3O4-ZrO2 composite catalysts also showed outstanding CO oxidation kinetics performance with low activation energies of 25.36 and 26.41 kJ/mol, and remarkable time-onstream stability, sustaining a near 100 % CO conversion rate for up to 25 h.The superior CO oxidation performance was associated with the smaller crystallite sizes, uniformly dispersed active sites, abundant oxygen vacancies, and enhanced redox properties, all of which stemmed from the strengthened interfacial interactions among the metal oxides upon CeO2 and ZrO2 incorporation.These findings offer valuable insights into the structure-property-activity relationships of the CuO-Co3O4-TMO composite catalysts, positioning the CuO-Co3O4-CeO2 and CuO-Co3O4-ZrO2 samples as promising candidates for low-temperature CO oxidation in sintering flue gas treatment.