Behavior and structure tuning of (Mn&Fe)AlOx-based catalysts for superior denitrification performance

Abstract

Generally, using transition metal oxides as catalysts is the typical method for ammonia-selective catalytic reduction (NH3-SCR) under the medium temperature zone (150–400 °C). The controllable structure and uniformly distributed active sites of (Fe&Mn)AlOx-based catalysts via a facilely operative and green prepared method were employed for high NO catalyzed efficiency and selectivity. Among them, the Mn1.2Al0.8Ox sample exhibited excellent low-temperature activity, and Fe1.2Al0.8Ox exhibited excellent N2 selectivity, which could be ascribed to the unique surface feature (more redox sites on Mn1.2Al0.8Ox and more acid sites on Fe1.2Al0.8Ox). This creative work has directly demonstrated the importance of coordination between the adsorption of species and electron transportation that emerged on active sites. Meanwhile, the reaction process has been clearly presented in in-situ DRIFTS, declaring the synergetic mechanism (Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism) in the systems. The Eley-Rideal mechanism could be the dominant one due to its rapid reaction rate. The predictable insights are beneficial for profoundly understanding the dual-sites synergetic interaction for controllable conversion rate and high selectivity in the medium temperature SCR process.