Ethanol Steam Reforming on Ni-Based Catalysts: Effect of Cu and Fe Addition on the Catalytic Activity and Resistance to Deactivation

Ethanol steam reforming (ESR) on a group of multifunctional xFeyCulONi-Beta catalysts was studied using in Xray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), temperature programmed reduction in hydrogen (H-2-TPR), temperature-programmed oxidation (TPO), and X-ray absorption fine structure (XAFS) techniques with a focus on the structural characterization of the active sites, the effect of different amounts of Cu and Fe phases and understanding the reaction pathway for the catalysts. The 1.5Fe1.5Cu10Ni-Beta catalyst exhibited very good catalytic performance for the ESR, including high activity, high H-2 selectivity, and low undesired products, because of the synergistic catalysis of Ni, Cu, and Fe phases. The Cu site preferentially facilitates the dehydrogenation of ethanol at the initial reaction step, and with subsequent Ni metal catalyzes dissociation of the C-C bond in acetaldehyde to form CO and CH4. The Fe phase, which has a tendency to be enriched on the alloy particle surface, is suitable for acetaldehyde and CH4 reforming above 350 degrees C. Moreover, the effect of the Cu-Ni(Fe) alloy could further to enhance the catalytic performance of the ESR reaction. The analyses of deactivated catalyst by means of several techniques suggest that the synergistic effect among Ni, Cu, and Fe phases on the spent catalysts proved to be highly resistant to coking, compared to the monometallic Ni catalysts, and the multifunctional catalyst exhibited very good antisintering ability.