Enhanced selective catalytic reduction of NOx with NH3 over homoatomic dinuclear sites in defective α-Fe2O3

Abstract Catalytic reactions that require more than one active sites are popular, such as selective catalytic reduction of NOx with NH3 (NH3-SCR) for the elimination of NOx contaminant containing redox and acid dinuclear sites. Doping/supporting other elements is a general strategy for introduction of the one that catalysts lack. Herein, we prepared a highly defective α-Fe2O3 with enhanced acid (Lewis and Bronsted) and redox properties on homoatomic dinuclear sites comprising more positively charged Fe3+ and oxygen vacancy-coupled Fe2+ ions. The NH3-SCR activity is improved at lower temperature without adding another acid transition metal. Furthermore, the significant amounts of Bronsted acid provide precaution against the poisoning of H2O and SO2. This work greatly broadened applicability of the state of the art concept of dinuclear sites for NH3-SCR and open a new avenue to enhance activity via defective engineering for a single metal oxide.