Effect of Mn/Cu Molar Ratios on CO Oxidation Activity of Mn-Cu Bimetallic Catalysts

The steel manufacturing industry is a major source of global air pollution, with sintering processes contributing over 70% of emissions, primarily carbon monoxide (CO), a significant uncontrolled pollutant. This study explores Mn-Cu bimetallic catalysts as a cost-effective and environmentally friendly alternative to noble metal-based systems, addressing the urgent need for efficient CO oxidation catalysts. Mn-Cu catalysts with different Mn/Cu molar ratios were synthesized via hydrothermal methods and systematically characterized using XRD, XPS, BET, H2-TPR, etc., to assess their physicochemical properties and catalytic performance. The Mn4Cu1 catalyst demonstrated the highest CO oxidation activity, achieving complete conversion at 175 °C. This performance is attributed to its optimal Mn/Cu molar ratio, high specific surface area, abundant oxygen vacancies, and superior redox properties. The catalyst’s enhanced performance is further supported by its low reduction temperature and high Mn3+ and Cu+ content, which promote efficient electron transfer and oxygen activation. These findings highlight the crucial role of Mn/Cu molar ratios in optimizing catalytic performance and offer valuable insights for designing high-efficiency, low-cost catalysts to reduce CO emissions in industrial applications.