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.