Highly Water-Resistant Ce-Doped CuMnO_x Catalyst for Durable CO Oxidation by Inhibiting Byproducts

Abstract

Air pollution is a serious challenge in the rapid development of the iron and steel industries. The development of water resistance in the CO catalyst is the key prospect in sintering flue gas terminal treatment. In the work described in this paper, we introduced Ce into CuMnO x to regulate its water resistance, and a model was proposed to explore the mechanism of carbonate product elimination. A 7.5% Ce-doped sample showed the best activity, increasing the reaction rate by 8 times, with the CO conversion rate over 90% at 110 °C and over 80% after 100 h in a humid environment. The sample characterization analysis showed that Ce intercalation breaks the surface charge balance and promotes electronic migration and the binding of external protons. Proper Ce-doping to enhance the surface Lewis and Bronsted acidity could inhibit the adsorption and solidification of acidic gas CO 2 on catalysts. Meanwhile, a Ce−Mn charge-transfer interaction passivates the overly compact binding of Mn sites to carbonate intermediates, making the adsorption and desorption of hydration products reach a good balance and inhibiting the formation of carbonate complexes. This study provides insights for the mechanisms of water resistance to strengthen the application of CuMnO x catalysts in humid environments.