Promoting N2 Selectivity of CeMnOx Catalyst by Supporting TiO2 in NH3-SCR Reaction

CeMnOx catalyst was synthesized by the combustion method, and the supported Ti/CeMnOx catalyst was subsequently prepared by wetness impregnation. Ti/CeMnOx catalyst exhibited higher N2 selectivity than CeMnOx catalyst in the selective catalytic reduction of NO by NH3 (NH3-SCR), and the generation of side products including in N2O and NO2 were discussed. N2 adsorption/desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (TPR), NH3 temperature-programmed desorption (TPD), and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) were carried out to reveal the promotion effect of TiO2 on the N2 selectivity of CeMnOx catalyst. Results indicated that loading TiO2 weakened the redox ability and enhanced the NH3 adsorption ability of CeMnOx catalyst, and thus inhibited NO/NH3 oxidation and facilitated the Eley–Rideal reaction pathways even at higher temperature.