(14d) Effects of Surface Species and Dispersion of CeO2 Supported Transition Metal Oxide Catalysts for NO Reduction By CO Reaction
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Applied Environmental Catalysis
Sunday, October 28, 2018 - 4:20pm to 4:35pm
In this study, series of CeO2 supported CoOx, FeOx, or NiOx catalysts were prepared by incipient wetness impregnation method for NO reduction by CO. Catalytic activity and catalyst physicochemical property were investigated by FTIR, BET, and Raman spectroscopy. No diffraction peaks due to crystalline CoO or Co3O4 were observed in XRD patterns under to 10 wt%, while nanocrystaline Co3O4 peaks at ~610cm-1 was observed in the Raman spectra with 5 wt% sample, indicating that 5-6 wt% CoOx/CeO2 contains monolayer coverage. Similarly, 1 wt% NiOx/CeO2 and 10 wt% FeOx/CeO2 also showed monolayer coverage. It was observed that both surface species and dispersion are closely related to the catalytic activity in NO reduction by CO. For example, for CoOx/CeO2 catalysts, monolayer and above monolayer coverage catalysts showed 80~90% CO and NO conversion at 300~400oC with high N2 selectivity (>90%), whereas sub-monolayer coverage catalysts had significantly low activity.