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

• Published in: Journal of environmental chemical engineering 2021-10, Vol.9 (5), p.106153, Article 106153
• Main Authors: Bie, Xuan, Wu, Kai, Jiao, Kunling, Zhao, Kun, Chen, Xiangyang, Ma, Suangchen
• Format: Article
• Language: English
• Subjects: Citric acid induced synthesis; Coordination mechanism; Electron transportation; SCR mechanism; Target N2 generation
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2021.106153

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. [Display omitted] (Mn&Fe)AlOx-based Catalysts with different surface features were fabricated by an environment-friendly method. The structure-activity relationship of the catalyst surface was systematically illustrated. Meanwhile, the evolution process and mechanism were discussed by in-situ DRIFTS. These are beneficial for profoundly understanding the dual-sites synergetic interaction for controllable conversion rate and high selectivity in the medium temperature SCR process. •(Mn&Fe)AlOx-based catalysts were fabricated with green and facile method.•Unique surface features for catalysts contributing to performance are discussed.•Matching electron transport ability and adsorption ability enhances SCR reaction.•In-situ DRIFTS results reveal both E–R and L–H mechanisms occur on the surfaces.