Cobalt Modification for Improving Potassium Resistance of Mn/Ce‐ZrO₂ in Selective Catalytic Reduction

Abstract

The three catalysts Mn/Ce-ZrO 2 , MnCo/Ce-ZrO 2 , and Mn/Co-Ce-ZrO 2 were applied to remove NO in simulated flue gas. Their selective catalytic reduction (SCR) activity and potassium resistance were studied. Catalysts with Co as a modifier of the support exhibited the best SCR activity. The catalyst Mn/Co-Ce-ZrO 2 had a larger surface area, higher dispersion of active components, larger amount of surface acid, and better redox characteristics than the other two catalysts, leading to a better SCR activity. X-ray photoelectron spectroscopy results proved the higher surface Mn 4+ concentration of K 0.3 Mn/Co-Ce-ZrO 2 . Pyridine adsorption analysis suggested that there was still a large amount of Lewis acid in Mn/Co-Ce-ZrO 2 even after potassium poisoning, demonstrating the higher resistance of this catalyst to potassium. Mn/Co-Ce-ZrO 2 with potassium addition had a relatively stable SCR activity in the presence of H 2 O and SO 2 .

Comparative study on K‐tolerance performance of Fe/ZrO2 and Fe/ZrO2‐W catalysts for NH3‐SCR of NOx

“…Previous research has shown that the introduction of suitable metals, such as copper (Cu), niobium (Nb), Ce and cobalt (Co), could promote the redox cycle of active species, and prevent the irreversible binding of active centers to K-species. 10,[23][24][25][26] Yao et al treated a cerium oxide/titania (CeO 2 -TiO 2 )/P25 catalyst with sulfuric acid to improve K-tolerance. It was shown that acid treatment could promote NH 3 adsorption by increasing the acidity of the catalyst surface, ensuring that abundant acid sites remained on catalyst surface after K-deposition.…”

“…At present, some strategies have been explored to alleviate the K‐poisoning of catalysts. Previous research has shown that the introduction of suitable metals, such as copper (Cu), niobium (Nb), Ce and cobalt (Co), could promote the redox cycle of active species, and prevent the irreversible binding of active centers to K‐species 10,23‐26 . Yao et al .…”