Bimetallic modification of MnFeOx nanobelts with Nb and Nd for enhanced low-temperature de-NOx performance and SO2 tolerance. (1st January 2023) - Song, Kunli
Graphical abstract: Highlights: MnFeO x nanobelts are bimetallically modified with Nb and Nd for the first time. The MnFeNb0.2 Nd0.1 O x achieves an improved NO x conversion and an enhanced tolerance of SO2 . The rational design of Nb and Nd enhances the adsorption of NH3 and NO and reduces the adsorption of SO2 . The de-NO x reaction over MnFeNb0.2 Nd0.1 O x follows both E-R and L-H mechanisms. Abstract: Nitrogen oxide (NO x ) is one of the key factors contributing to air pollution, and selective catalytic reduction with ammonia (NH3 -SCR) is widely used for denitrification (de-NO x ). To effectively deal with the NO x pollution, it is urgent to develop efficient catalyst working at below 300 °C with a wide operating temperature window. Herein, a series of ferromanganese oxides (MnFeO x ) nanobelts are bimetallically modified with niobium (Nb) and neodymium (Nd) for the first time via electrospinning method. The resultant MnFeNbNdO x catalysts present improved low-temperature de-NO x performance and sulfur dioxide (SO2 ) tolerance, particularly MnFeNb0.2 Nd0.1 O x who achieves a NO x conversion up to over 90 % during the range of 120–330 °C and an enhanced tolerance of water (H2 O) and SO2 . Experimental and theoretical calculations confirm that strong adsorption of nitric oxide (NO) and ammonia (NH3 ) and weak adsorption of SO2 with the synergy of Nd, Nb and Mn enable MnFeNb0.2 Nd0.1 O x excellent SCR activity and good SO2 tolerance. In-situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) further reveal that the de-NO x reaction over MnFeNb0.2 Nd0.1 O x follows both Eley-Rideal (E-R) and Langmuir-Hinshel-wood (L-H) mechanisms. This study will inspire the further design and study of the synergy of transition metals and rare earth elements for de-NO x .