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.