Performance study for NH3-SCR at low temperature based on different methods of Mnx/SEP catalyst

Abstract

Abstract In the quest for highly efficient low-temperature ammonia selective catalytic reduction (NH3-SCR) catalysts, the preparation of a series of catalysts (Mnx/SEP) in which manganese oxide is supported in sepiolite (SEP) is described for the first time. Three different methods are used, i.e., in situ deposition, impregnation, and precipitation, and the effect of the preparation method on the performance of the catalysts for the NH3-SCR reaction is evaluated. The catalysts are fully characterized by SEM, BET, TEM, XRD, XPS, and NH3-TPD. The results herein presented suggest that the Mn8/SEP catalyst prepared by in situ deposition method exhibits the highest catalytic activity in the temperature range of 100–300\u202f°C, with a high apparent turnover frequency of around 3.1\u202f×\u202f10−4\u202fs−1. Furthermore, the in situ deposition method affords the catalyst with the highest specific surface area and with more acidic sites, which is beneficial for the catalytic reaction. This improves the NH3 adsorption performance of the catalyst and the denitration activity.