Influence of different supports on the physicochemical properties and denitration performance of the supported MnCe-based catalysts for NH₃-SCR

A series of supported Mn-Ce-based catalysts were prepared using TiO₂, SAPO-34, and Al₂O₃ as supports. The physicochemical properties of the obtained catalysts, such as structure, specific surface area, reduction properties, surface elements and acidity were characterized with XRD, BET, H₂-TPR, XPS and Py-FTIR. The results showed that MnCeO_x/SAPO-34 catalyst exhibited a larger specific surface area (439.87 m²/g), medium amount of Lewis acid sites and the weakest reduction property. In the MnCeO_x/Al₂O₃ catalyst, the concentration of Mn⁴⁺ and Ce³⁺ was relatively high, and the amount of acid sites is the lowest. However, TiO₂ as the catalyst support could enhance the reduction property, and increase the amount of Lewis acid sites and the concentration of Mn and Ce. NH₃-SCR performances of the catalysts were evaluated using a flow type fixed bed reactor. The results showed that MnCeO_x/TiO₂ catalyst presented the best catalytic performance, over which near 100% NO conversion was reached at 280 ℃ under a gas hourly space velocity of 42000 h^-1. The combination of characterization and reaction results indicated that the good reduction behavior and large amount of Lewis acid sites were beneficial to the enhancement of the catalytic performance for low-temperature NH₃-SCR reaction.