Bimetallic iron–copper and iron–nickel nano-catalysts over ceria support for medium temperature shift reaction

Abstract

Iron/ceria catalysts promoted by copper or nickel, were studied in medium temperature shift (MTS) reaction for hydrogen production and purification. Samples were characterized by X-Ray Diffraction (XRD), N2 adsorption-desorption (BET), temperature programmed reduction (TPR), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), and transmission electron microscope (TEM) analysis. Among xFe/CeO2 (x = 2, 5, 8, 10 wt%) samples, 8Fe/CeO2 showed the best performance, due to appropriate amount and good dispersion of active phase on the support (45% CO conversion at 390 °C). Then, to enhance the CO conversion, 2% of Ni or Cu were added to the catalyst. However CO conversion using Cu promoter was lower than Ni containing one, (25 and 45%, at 300 °C, respectively.), but due to better reducibility and lack of methane production, copper was selected as promoter. Eventually, the effect of Cu loading (2, 4, 8, 12 wt %) was also investigated, and 8Fe–8Cu/CeO2, with >80% CO conversion at 390 °C, showed the best performance with appropriate stability.