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CO-SCR was considered as one of the most optimum technologies for synergistic removal of nitrogen oxides and carbon monoxide from flue gas. CuCe catalyst showed excellent NO x and CO catalytic activity in the range of 250–500 °C because of its unique physicochemical property. Herein, the mechanism of CuCe catalyst in the CO-SCR reaction at different temperature was studied via in situ DRIFTS characterization. The result indicated that the adsorbed CO species could react with gaseous NO molecules over CuCe catalyst at 150 ºC, implying that the E-R mechanism was obeyed at lower temperature. Moreover, the nitrate/nitrite species and adsorbed CO species could react with each other on the surface of CuCe catalyst at 350 ºC, indicating that the L-H mechanism was followed in the CO-SCR reaction at higher temperature. This work proposed the reaction mechanism of CuCe catalyst at different temperature for NO reduction by CO, which could provide a theoretical direction for the optimization of CuCe catalyst and promote its application in industrial production. [Display omitted] • CuCe catalyst exhibited outstanding catalytic performance for NO and CO. • CuCe catalyst had highest ratio of Cu+ and excellent redox capacity. • E-R mechanism was obeyed at 150 °C, while both E-R and L-H at 350 °C. • Mechanism model of CuCe catalyst for CO-SCR reaction was proposed. [ABSTRACT FROM AUTHOR]

The study of SCR catalysts for nitrogen oxides reduction with NH 3 had recently attracted much attention. As a typical heavy metal element, Pb was prone to seriously damage the denitrification performance of SCR catalysts in flue-gas environment. This work systematically reviewed the mechanisms of Pb poisoning and anti-deactivation measures reported these years for SCR catalysts. The mechanisms of Pb poisoning were summarized from both physical and chemical aspects, including the specific surface area, redox ability and surface acidity of the catalysts, and the corresponding reaction paths of the catalysts were also considered during the SCR process. In the meantime, this paper reviewed the anti-deactivation mechanisms and measures currently used to solve the problem of lead poisoning for SCR catalysts. The main methods included adding active substances to improve the redox ability and surface acidity of the catalysts, using ions or anti-poisoning sites to preferentially bind to Pb species, or using the structural characteristics of the carriers to prevent Pb from contacting with active substances. The concrete measures included the modification of catalysts with metal oxides and solid super acids, the change of carriers' structure, and the dual effect of carriers and active materials. Finally, a prospect of lead poisoning for further research on SCR catalysts was proposed. [Display omitted] • Physical and chemical mechanisms of Pb poisoning on SCR catalyst were reviewed. • Anti-inactivation mechanisms for SCR catalyst in the presence of Pb were clarified. • Recent advances in anti-Pb measures of SCR catalysts were summarized. • Challenges for Pb poisoning catalyst in industrial application were proposed. [ABSTRACT FROM AUTHOR]