In situ TEM study of the Ru-RuO_x/TiO₂ catalyst for low temperature methanation of carbondioxide

The Ru-RuO x /TiO 2 catalyst has been shown to be able to produce methane from hydrogen and carbon dioxide at room temperature and atmospheric pressure at reasonably high rates (TOF: 10 -6 at 25C and 10 -4 at 90C). The best results were obtained using the P25 support (Degussa 80% anatase and 20% rutile) in the 55-60 m 2 /g surface area range. The optimal loading for the metal is 3.8% Ru metal. We found that in the most active catalysts, the metal (>90%) is selectively loaded on the rutile crystallites. This distribution shows up clearly in a 500C reduced sample (fig.l) in which the size of the metal particles has increased.