Steam reforming of methanol over cobalt catalysts: Effect of cobalt oxidation state

Temperature-programmed reduction (TPR) employing hydrogen and methanol as reducing agents and in-situ X-ray diffraction have been employed to investigate the oxidation state of Co-Mn catalysts prepared by oxidative or pyrolytic treatment of fumarate precursors and correlate observations with catalyst activity in methanol reforming. Pyrolytic treatment leads to almost fully reduced catalysts, while catalysts prepared by oxidation are of the spinel structure and get reduced in a stepwise fashion. Both hydrogen and methanol are efficient reducing agents. Interaction of methanol with the catalyst surface occurs more readily with the reduced catalysts.