The selective reduction of NO by C3H(8) and the sensitivity to H2O and SO2 have been studied over monolithic cordierite-based Fe/Al2O3 catalysts, which were prepared by the sol-gel and impregnation method. The catalysts were investigated by N-2 adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. Results showed that NO reduction was more than 90% in the absence of oxygen at 500 degrees C and in the presence of oxygen at 600 degrees C respectively. In a continues test of 12 h at 600 degrees C, 0.02% of SO2 caused an irrecoverable decrease of NO conversion from 94% to 85% and 2.5% of H2O caused a drop of NO conversion from 86% to 56%, while NO conversion totally recovered when H2O was removed. The catalysts lost 15% of the initial activity after a hydrothermal treatment due to the agglomeration of iron oxide nanorods. Sulphidation treatment caused about a loss of 30% of the initial activity because of the deposited SO species. In situ study by DRIFTS indicated that coexisting H2O influenced the formation NO2 adspecies and unidentate nitrate, while SO2 slightly inhibited the formation of NO2/NO3 species, but promoted the formation of acetate/formate species during NO reduction by C3H8. Based on the results, a preliminary mechanism was proposed and discussed. The results may help understand the fundamental performance of monolithic cordierite-based Fe/Al2O3 catalysts and provide some reference for SCR-HC catalyst design. (C) 2016 Elsevier Ltd. All rights reserved.