Cu/Mn co-doped Co3O4 with enhanced oxygen activation for low-temperature CO oxidation

Abstract

The low-temperature catalytic oxidation activity of cobalt oxide (Co₃O₄) is effectively enhanced by metal doping. A series of Cu/Mn co-doped Co₃O₄ catalysts with controlled doping ratios were synthesized via co-precipitation and subsequently evaluated for carbon monoxide (CO) oxidation. The optimal low-temperature activity was achieved at a Cu/Mn ratio of 0.35/0.65, with the catalyst also demonstrating robust stability. Combined characterization results (XRD, FT-IR, XPS, H₂-TPR, and O₂-TPD) reveal that Cu/Mn co-doping weakens Co–O bonding and enhances low-temperature reducibility and oxygen mobility, thereby generating abundant surface oxygen defects. These defects facilitate the activation of molecular oxygen (O₂), thereby increasing CO conversion at low temperatures. This research provides valuable insights into the development of highly efficient catalysts for CO oxidation.