MnOx-decorated VOx/CeO2 catalysts with preferentially exposed {110} facets for selective catalytic reduction of NOx by NH3

Highly dispersed MnOx-decorated VOx/CeO2 catalysts with preferentially exposed {110} facets were chosen to improve the low-temperature (200 - 250 degrees C) NH3-SCR activity. In this work, the catalytic data on NH3-SCR performance indicated that the improved catalytic activity were achieved when both VO X and MnOx were presented on the {110} facet of CeO2 nanorods. It could be deduced that the highly dispersed surface monomeric vanadium species were the reason for the high NH3-SCR activity from V-51-Nuclear Magnetic Resonance (NMR), Raman, X-ray diffraction (XRD) and Transmission electron microscopy (TEM). It was also suggested that CeO2{110} facet and surface oxygen vacancy defects had significant effects on the promotion of NH3-SCR performance. Furthermore, the redox cycle of V5+/V4+ and the quantities of NH3(L) species and bridging nitrate species were increased by the introduction of Mn. The Langmuir-Hinshelwood mechanism is possible because abundant surface NH3(L), NH4+(B) and bridging nitrate species were produced as intermediates studied via in situ DRIFTs.