A New Approach to the Preparation of Stable Oxide-Composite Cobalt-Samarium Catalysts for the Production of Hydrogen by Dry Re-Forming of Methane

Abstract

A new approach to preparing a series of Co/Sm2O3 catalysts for hydrogen production by dry re-forming of methane (DRM) is developed. The catalysts precursors are synthesized by a simple method, including evaporation of aqueous solutions of cobalt and samarium nitrates, followed by a short-term calcination of the resulting material. The as-prepared and spent catalysts are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature-programmed reduction (H2-TPR), and thermogravimetric analysis (TGA). It is shown that the content of cobalt in the synthesized materials affects their phase composition and carbonization resistance in the DRM reaction. It is demonstrated that preheating under N2 affords catalysts providing stable hydrogen and CO yields of 94-98 % for at least 50 h at 900°C. These yields are among the highest ones currently available for DRM catalysts derived from Co-Sm complex oxides. It is found that reduction in the amount of cobalt in the catalyst and its preheating to an operating temperature of 900°C in a nitrogen flow con-tribute to preventing catalyst carbonization and metal particles sintering.