CO and CO₂ Methanation Over Supported Cobalt Catalysts

Abstract

CO and CO₂ methanation was investigated over cobalt catalysts supported on different supports such as γ-Al₂O₃, SiO₂, TiO₂, CeO₂, and ZrO₂. Among them, the cobalt catalyst supported on the high-surface-area CeO₂ was determined to be the most active for both CO and CO₂ methanation. These catalytic activities increased with increasing surface area of CeO₂. To increase the specific catalytic activity for CO and CO₂ methanation, various Co–CeO₂ catalysts with different cobalt contents were prepared with co-precipitation method. The optimum cobalt content was determined for both reactions. The prepared catalysts were characterized with N₂ physisorption, temperature-programmed reduction with H₂, pulsed-chemisorption of CO₂, temperature-programmed desorption of CO₂, and X-ray diffraction. The high cobalt dispersion and strong CO₂ adsorption appeared to be responsible for the high catalytic activity for CO and CO₂ methanation, respectively. This Co–CeO₂ also showed the stable catalytic activity even after an exposure to high-temperature reaction conditions.