An efficient defect engineering strategy to enhance catalytic performances of Co₃O₄ nanorods for CO oxidation

Catalytic oxidation of CO at ambient temperature is an important reaction for many environmental applications. Here, we employed a defect engineering strategy to design an extraordinarily effective Sn-doped Co₃O₄ nanorods (NRs) catalyst for CO oxidation. Our combined theoretical and experimental data demonstrated that Co²⁺ in the lattice of Co₃O₄ were substituted by Sn⁴⁺. Based on a variety of characterizations and kinetic studies, this catalyst was found to combine the advantages of the nanorod-like morphology for largely exposing catalytically active Co³⁺ sites and the promotional effect of Sn dopant for adjusting the textural/redox properties. Additionally, the Sn-substituted Co₃O₄ NRs can be further activated via heat treatment to achieve low-temperature CO oxidation (T₁₀₀ ∼ -100 °C) with excellent stability at ambient temperature. This study reveals the importance of Sn-substitution of inactive Co²⁺ in Co₃O₄ and provides an ultra-efficient catalyst for CO oxidation, making this robust material one of the most powerful catalysts available up to now.