H2-production from CO2-assisted ethanol steam reforming: The regeneration of Ni-based catalysts

Al2O3-, MgO-, Y2O3-, La2O3- and ZrO2-supported Ni catalysts were prepared using supports obtained by precipitation in the presence of active carbon as a templating agent. The effect of CO2 introduction as reactant on the ethanol steam reforming (ESR) was analysed as a function of the characteristics of the catalysts using H2O/ethanol = 1.6. The catalysts were characterized before and after their use in the CO2-assisted ethanol steam reforming (CDESR, ethanol/H2O/CO2 = 1/1.6/1.6 mol ratio). For Ni/La2O3 poorer structured carbon deposits were found after CDESR. Moreover, for Ni/Y2O3 and Ni/La2O3 the regeneration by CO2-treatment during ESR was studied. The CO2 treatment partially restored their catalytic performance, CO2 can act as a mild oxidant removing part of the carbonaceous deposits; this behaviour is related with the basic characteristics of the catalysts.