Influence of Fe addition on the performance of Pt/Co/BaO/Al2O3 catalyst in the presence of SO2: Kinetics and in-situ DRIFT study

In order to improve NOx storage and reduction (NSR) kinetics over Pt/Co/Ba/Al2O3 catalyst in the presence of SO2, Fe was added as a promoter to inhibit sulfation. A NOx analyzer was used to measure the NOx concentration of the gas phase and in-situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy was dedicated to analyze the interaction between the adsorbed reactive species from the gas phase and solid catalyst surface. NSR results showed that the addition of Fe to Pt/Co/BaO/Al2O3 increased the NOx uptake. The presence of Fe inside catalyst contributed to enhancing the ability of resistance to SO2 exposure. In situ DRIFT study confirmed that Fe played a role as an active inhibitor to sulfation based on the decreased intensity of band at 1120 cm−1. An isothermal temperature reduction (ITR) experiment at 300 °C showed that Fe would work to improve the reduction ability of stored NOx in the lean cycle and catalyst regeneration during the rich cycle.