Effect of K‑Modified Blue Coke-Based Activated Carbon on Low Temperature Catalytic Performance of Supported Mn–Ce/Activated Carbon

• Published in: ACS omega Vol. 7; no. 10; pp. 8798 - 8807
• Main Authors: Shen, Zhenghua, Xing, Xiangdong, Wang, Sunxuan, Lv, Ming, Li, Jinke, Li, Tao
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 15-03-2022
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.1c07076

To clarify the K modified effects over activated carbon (AC) supported Mn–Ce oxide catalysts, several Mn–Ce/AC and xK–Mn–Ce/AC mixed oxide catalysts prepared via an impregnation method supported on AC were investigated for low-temperature selective catalytic reduction (SCR) of NO with NH3 in the simulated sintering flue gas. The Mn–Ce/AC catalyst with a K loading of 8% showed the highest catalytic activity, corresponding to 92.1% NO conversion and 92.5% N2 selectivity at 225 °C with a space velocity of 12,000 h–1. Furthermore, the 0.08K–Mn–Ce/AC catalyst exhibited better resistance to SO2 and H2O than Mn–Ce/AC, which could convert 72.3% and 74.1% of NO at the presence of 5% SO2 and H2O, respectively. After K modification, the relative ratios of Mn4+/Mn n+ as well as Ce3+/Ce n+ and surface adsorbed oxygen increased. Additionally, the reduction performance of the catalyst was improved obviously, and both acid strength and quantity of acid sites increased significantly after the K species were introduced in Mn–Ce/AC. Especially, the NO adsorption capacity of the catalyst was enhanced, which remarkably promoted the denitration efficiency and SO2 resistance. The SCR of NO with NH3 on K–Mn–Ce/AC catalysts followed the L-H mechanism.