Excellent low-temperature catalytic performance of nanosheet Co-Mn oxides for total benzene oxidation

Abstract A series of Co a Mn b O x oxides (a/b = 1:1∼7:1) at 500 °C and Co 2 Mn 1 O x at a temperature range of 300–700 °C were prepared by an oxalate co-precipitation method and evaluated of catalytic performance for benzene total oxidation. It is found that Co 2 Mn 1 O x catalyst displays the best activity among all the Co a Mn b O x oxides. The typical uniform nanosheet morphology plays a vital role in achieving the relatively high activity of Co 2 Mn 1 O x . A detailed characterization has illustrated that the calcination temperature is also an important factor to influence the structure, physico-chemical properties and thus catalytic performance of Co 2 Mn 1 O x . Co 2 Mn 1 O x calcinated at 300 °C (CM300) presents pretty thin nanosheet and small particle size of 6.6 nm. It displays a better low-temperature catalytic activity than those obtained at temperatures of >300 °C: under the conditions of 20,000 mL g −1  h −1 and 1500 ppm of benzene, the temperature at 90% conversion of benzene oxidation is 191 °C, which is lower than that of some related reports in the literatures. Furthermore, CM300 performed excellent long-term stability. It is concluded that the superior catalytic performance of CM300 is associated with its relatively large specific surface area, good low-temperature redox property, abundant active oxygen species and active components (Co 2+ and Mn 4+ ). Co-Mn oxides will be the potential alternative of precious metals for the removal of volatile organic compounds in the industrial field.