Er-modified MnOx for selective catalytic reduction of NOx with NH3 at low temperature: Promoting effect of erbium on catalytic performance

Abstract

Various Er modified MnOx catalysts were synthesized using co-precipitation approach and tested in the selective catalytic reduction of NOx by ammonia (NH3-SCR). Catalysts were analyzed with various characterization techniques, and it is found that the doping of Er can enormously enhance the catalytic performance of MnOx catalyst. MnEr0.1 demonstrates advantageous catalytic performance in the NH3-SCR reaction owing to rich surface acidic sites, high surface content of Mn4+, superior redox capacity, and enhanced surface-adsorbed oxygen. From diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) analysis, it is suggested that the MnEr0.1 catalyst follows mainly Eley-Rideal mechanism while MnOx is dominated by Langmuir–Hinshelwood mechanism.