Preparation, characterization, and properties of monolithic Fe/Al2O3/cordierite catalysts for NO reduction with C2H6

Monolithic cordierite-based Fe/Al2O3 catalysts were prepared using a sol-gel and impregnation method and characterized by N-2 adsorption, XRD, SEM, XPS, H-2-TPR, and an activity test for the reduction of NO with C2H6. The results indicated that the textural properties, surface morphology, nanorod size, crystallinity, reducibility, and NO reduction activity of the catalysts were correlated with the iron loading. The order of the C2H6-SCR activity was as follows: 5.5Fe/Al2O3/CM > 3.5Fe/Al2O3/CM > 8Fe/Al2O3/CM > 2Fe/Al2O3/CM. High activity (97% NO conversion) was observed with 5.5 wt.% iron at 600 degrees C in the presence of oxygen. The results indicate that the iron oxide nanorods distributed on the surface of the Al2O3 layer may act as the SCR active site. Based on in situ DRIFTS spectral analysis, O-2 can act as a promoter for the formation of the NO2/NO3- species. However, the formation of -NCO species does not appear to be accelerated by O-2. (C) 2015 Elsevier B.V. All rights reserved.