Hydrogen production by iso-octane steam reforming over Cu catalysts supported on rare earth oxides (REOs)

The present work aims to investigate the steam reforming (SR) of liquid hydrocarbons toward hydrogen production, employing iso-octane as gasoline surrogate, over Cu catalysts supported on rare earth oxides (REOs). An extensive characterization study, involving X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction (TPR), is undertaken to correlate the structural, morphological and surface properties of catalysts with their reforming performance. Several parameters related to the effect of operation temperature (600–800 °C), steam/carbon ratio (1–3) and Cu loading (0–25 wt%) on the catalytic performance are investigated. The results reveal that the best performance is obtained over the Cu/CeO₂ catalysts at a steam/carbon ratio of 3; H₂ yields as high as ∼55% are obtained at the expense of CH₄ and higher hydrocarbons. Concerning the influence of oxide carries on reforming efficiency the following order, in terms of H₂ yield, is recorded: CeO₂ ? Nd₂O₃ > Gd₂O₃ > Sm₂O₃ ≈ Pr₆O₁₁ ≈ La₂O₃. However, a notable deterioration of Cu/CeO₂ catalyst is observed in long term stability tests, ascribed to carbon deposition and catalyst sintering.