Efficient CO2-regeneration of Ni/Y2O3La2O3ZrO2 systems used in the ethanol steam reforming for hydrogen production

This paper reports the study of substoichiometric ethanol steam reforming (ESR) (H2O/ethanol = 1.6 mol ratio) for hydrogen production over new Ni/Y2O3La2O3ZrO2 catalysts. ZrO2-based supports containing Y2O3 and/or La2O3 were prepared by precipitation using active carbon as the templating agent and the Ni-catalysts were then prepared by impregnation. CO2 was used as regenerating agent and its effect was analysed as a function of the characteristics of the catalysts. The CO2 treatment proved to be a powerful tool for regenerating deactivated Ni catalysts through mild oxidation of carbon deposits; this phenomenon is related to the basic characteristics of the catalysts. For Ni/12Zr29Y13La, a high H2 yield and the smallest amount of poorly ordered carbon deposits were determined; full ethanol conversion was achieved during the last 50 h of a long-term (280 h) experiment with periodic CO2 treatments.