The impact of ruthenium, lanthanum and activation conditions on the methanation activity of alumina-supported cobalt catalysts

The influence of catalyst activation conditions and the presence of promoters (La, Ru) on the performance of γ-alumina-supported Co catalysts for the methanation reaction has been investigated. Physicochemical properties, Co crystallite size and the extent of Co3O4 reduction to metallic Co for both the monometallic and promoted catalysts were evaluated. Combined La and Ru addition produced the greatest activity improvement for converting carbon monoxide (CO) and hydrogen (H2) to methane. Reduction conditions used to activate the catalyst were also found to have a direct influence on methanation activity. Maintaining the catalyst at 400 °C for 10 h during reduction enhanced catalyst activity, as well as increasing the H2 concentration in the reducing gas stream. Characterisation of the reduced catalysts demonstrated that the extent of Co-oxide reduction to Co metal was the key to the improved methanation activity.