The superior performance of CoMnOx catalyst with ball-flowerlike structure for low-temperature selective catalytic reduction of NOx by NH3

A novel ball-flowerlike catalyst (CoMnOx-BF) was developed by hydrothermal method for the selective catalytic reduction (SCR) of NOx by NH3. Besides, a counterpart sample (CoMnOx) was prepared by coprecipitation way for comparison. The activity test results demonstrated that CoMnOx-BF catalyst exhibited admirable SCR performance and N-2 selectivity in a broad temperature range of 150-350 degrees C, along with an excellent resistance to SO2 and high durability. Based on characterization experiments, it could be found that the superior surface area resulted from suppressed crystallization, the enrichment of surface labile oxygen and Mn4+, the stronger surface acidity and redox ability were all beneficial to the NH3-SCR performance of CoMnOx-BF catalyst. Additionally, the enhanced NO oxidation and more activated ad-reactants on catalyst surface could also conduce to the outstanding SCR activity of CoMnOx-BF at low temperature.