Experimental and mechanism investigation on CO catalytic oxidation performance based on CuMn2O4 catalysts

Abstract

To reduce the carbon monoxide (CO) emissions in sintering flue gas, this study employed a catalytic oxidation approach to convert CO into carbon dioxide (CO₂) at low temperatures. The Cu-Mn catalysts were synthesized using co-precipitation methods. The effects of various reaction conditions, such as the Cu/Mn ratio and reaction temperatures, on CO catalytic efficiency was investigated. The results indicated that when the Cu/Mn ratio was 1:2, the catalytic efficiency was 98.34 % at approximately 105 °C. Furthermore, the catalysts remained stable after continuous testing. Based on density functional theory (DFT), a model for the adsorption of CO molecules was established. The adsorption characteristics between CuMn₂O₄ and CO, as well as the changes in surface charge distribution before and after adsorption, were systematically investigated. The research results indicated that the adsorption of CO on the surface of CuMn₂O₄ is a chemical adsorption process. Among the various adsorption sites, CO exhibits a greater affinity for the Mn-top site, with an adsorption energy of − 1.18 eV. During the adsorption process, some electrons from CO are transferred to the surface of the catalyst, resulting in orbital hybridization. Additionally, this paper investigated the reaction pathways involved in the CO oxidation process. These findings provide new insights for the optimization and screening of catalysts, which are significant for the fields of industrial flue gas purification and catalytic science.