In order to gain insight into the cobalt-support interactions for designing a better supported cobalt catalyst system for hydrogen production via ethanol steam reforming, the catalytic properties of an unsupported active component, bulk cobalt oxides, were investigated. The phase transformation of cobalt oxides and the corresponding catalytic activity in ethanol steam reforming was studied. Through in-situ XRD and DRIFTS studies, it was discovered for the first time that two metallic phases (hcp and fcc cobalt) exist in cobalt under the reforming conditions and possess different activity for hydrogen production. Furthermore, the addition of CeO₂ to cobalt was shown to hinder the sintering and the phase transformation in the hcp cobalt nanoparticles. Another promoting effect of CeO₂ was found to divert the reaction pathways toward an increase of hydrogen selectivity. Thus, the hcp cobalt promoted by CeO₂ shows a much higher catalytic activity for hydrogen production than an unpromoted cobalt catalyst.

In a separate work, a novel supported cobalt catalyst system for ethanol steam reforming was further studied. CeO₂-ZrO₂ support was chosen for cobalt to study a possible synergistic effect of CeO₂ and ZrO₂ toward the reforming reaction. This synergistic effect promotes the catalytic activity of Co/CeO₂-ZrO₂ catalyst by suppressing methanation favored on ZrO₂ supports, as well as by stabilizing the surface area which of CeO₂ supported is much smaller due to sintering.

In addition, a study regarding how various synthesis techniques as well as the pre-reduction process influence the catalytic properties of Co/CeO ₂-ZrO₂ catalyst for ethanol steam reforming is presented. The supported catalysts were synthesized by incipient wetness impregnation and coprecipitation followed by detailed characterizations using nitrogen adsorption, TEM-EDX, XRD, H₂-TPR, and CO chemisorption techniques. Metal-support interaction is shown during the pre-reduction of the impregnated catalyst and plays a crucial role in the enhancement of catalytic activity, which was not observed in the less active coprecipitated catalysts.

Finally, the formation of the water-induced cobalt oxides by re-oxidizing the metallic cobalt in the pre-reduced Co/CeO₂-ZrO₂ catalyst was verified through in-situ TPR and in-situ XPS studies in water-assisted ethanol decomposition and ethanol steam reforming. The presence of these cobalt oxides in the catalyst is shown to be associated with the catalyst pre-reduction and the feed stream conditions in the reaction.