Effect of Ba on the catalytic performance of Co-Ru/Al2O3 catalyst for Fischer-Tropsch synthesis.

[Display omitted] • The synergistic effect between Ba and Ru was reported at the first time. • An improved CO conversion and excellent selectivity to high C 5 + selectivity was obtained. • The introduction of Ba induced both site poisoning and electronic effects. • The synergistic effect between Ba and Ru was responsible for the enhanced CO dissociation ability. • Other alkali earth metal promoters had a similar influence on the Co-0.1Ru/Al 2 O 3 catalysts for the FTS reaction. Alkali earth metals and Ru are famous selectivity promoters in cobalt-based Fischer-Tropsch synthesis. Ba has displayed as an effective selectivity promoter, however, the presence of Ba leads to a dropped CO conversion yield. To combine the advantages of Ba and Ru in promoting selectivity, Ba-modified alumina was fabricated and used as the supports for Co and Co-Ru catalysts. Promotion of Co/Al 2 O 3 by a combination of Ru and Ba achieved an increase of CO conversion and a low CH 4 selectivity due to the enhanced CO dissociation than unmodified and a single additive modified catalyst. The influences of other alkali earth metal additives were also investigated, which had a similar impact that of Ba on the Co-Ru catalysts for promoting FTS reaction. [ABSTRACT FROM AUTHOR]