Steam Reforming of Bio-Ethanol to Produce Hydrogen over Co/CeO2 Catalysts Derived from Ce1-xCoxO2-y Precursors

A series of Ce1 ́xCoxO2 ́y precursors were prepared by homogeneous precipitation using urea as a precipitant. The Co/CeO2 catalysts obtained from the Ce1 ́xCoxO2 ́y precursors were used for the steam reforming of ethanol to produce hydrogen. Co ions could enter the CeO2 lattices to form Ce1 ́xCoxO2 ́y mixed oxides at x ď 0.2 using the homogeneous precipitation (hp) method. CeO2 was an excellent support for Co metal in the steam reforming of ethanol because a strong interaction between support and metal (SISM) exists in the Co/CeO2 catalysts. Because Co/CeO2 (hp) prepared by homogeneous precipitation possessed a high BET surface area and small Co metal particles, Co/CeO2 (hp) showed a higher ethanol conversion than the Co/CeO2 catalysts prepared using the co-precipitation (cp) method and the impregnation (im) method. The selectivity of CO2 over Co/CeO2 (hp) increased with increasing reaction temperature at from 573 to 673 K, and decreased with increasing reaction temperature above 673 K due to the increase of CO formation. The carbonaceous deposits formed on the catalyst surface during the reaction caused a slow deactivation in the steam reforming of ethanol over Co/CeO2 (hp). The catalytic activity of the used catalysts could be regenerated by an oxidation-reduction treatment, calcined in air at 723 K and then reduced by H2 at 673 K.