Microspherical MnO2-CeO2-Al2O3 mixed oxide for monolithic honeycomb catalyst and application in selective catalytic reduction of NOx with NH3 at 50–150 °C

Abstract

MnOx-CeO2-Al2O3 microspheres (MSs) were successfully designed and synthesized via spray drying (SD) and easily used for monolithic honeycomb catalyst (MHC). The as-obtained MnOx-CeO2-Al2O3 (SD) catalyst exhibited a great BET surface area of 201.4 m2/g, a pore volume of 0.29 cm3/g, and an average pore diameter of 5.8 nm. Furthermore, the MnOx-CeO2-Al2O3 (SD) MSs delivered much more Olatt sits resulting in enhanced catalytic activity at low temperature. The MnOx-CeO2-Al2O3 (SD) performed excellent NOx conversion of 97.4% and N2 selectivity of 94.5% at 150 °C with a gas hourly space velocity (GHSV) of 15,000 h−1, and NOx concentration of 500 ppm. Even at 50 °C and 100 °C, the titled product still exhibited great N2 selectivity of 95.5% and 96.1%, respectively, corresponding to the NOx conversion of 55% and 98.0%, respectively. The MnOx-CeO2-Al2O3 (SD) monolithic honeycomb catalyst (MHC) was prepared by vacuum-impregnation method. The MnOx-CeO2-Al2O3 (SD-MHC) delivered NOx conversion of 93% at 150 °C with a GHSV of 2000 h−1, and NOx concentration of 500 ppm. Even at 50 °C and 100 °C, the titled product still performed NOx conversion of 55% and 83%, respectively. The MnOx-CeO2-Al2O3 (MHC) performed great catalytic activity in the low temperature arrange from 50 to 150 °C and presented potential application in stationary industrial installations.