Hydrogen production through alcohol steamreforming on Cu/ZnO-based catalysts

Hydrogen production by steam reforming of methanol and ethanol is studied over a series of Cu/ZnO/Al2O3 catalysts prepared by different coprecipitation procedures and modified with the introduction of Ni and Co. The catalysts are characterized using N2 physisorption, X-ray diffraction (XRD), temperature programmed reduction (TPR) techniques, N2O decomposition, high resolution transmission electron microscopy (HR-TEM) and thermogravimetric analysis (TGA). Despite the influence of the preparation method on the texture and structure of Cu/ZnO/Al2O3 catalysts, their catalytic behavior appears not significantly affected. While Cu/ZnO/Al2O3 shows poor H2 selectivity in the ethanol steam reforming reaction, the presence of a second metal (Ni or Co) significantly improves the reforming reaction. Although coke deposition remains a drawback for these systems, formation of an alloy between Ni and Cu appreciably reduces carbon deposition with respect to the Co/Cu-based system

The identification of the structural phases of CexZr1-xO2 by Eu(III) luminescence studies

Despite the wide application of ceria-zirconia based materials in Three Way Catalysts (TWCs), Solid Oxides Fuel Cells (SOFCs), and H2 production and purification reactions, an active debate is still open on the correlation between their structure and redox/catalytic performances. Existing reports support the need of either (i) a homogeneous solid solution or (ii) materials with nanoscale heterogeneity to obtain high activity and stability. Here we report on a simple and inexpensive approach to solve this problem taking advantage of the luminescence properties of Eu(III), used as a structural probe introduced either in the bulk or on the surface of the samples. In this way, the real structure of ceria-zirconia materials can be revealed even for amorphous high surface area samples. Formation of small domains is observed in catalytically important metastable samples which appear homogeneous by conventional XRD