Characterization of new Co and Ru on α-WC catalysts for Fischer-Tropsch reaction. Influence of the carbide surface state.

Anne Griboval (1) , Jean-Marc Giraudon (1) , Ivan Twagishema (1) , Ginette Leclercq (1) , Maria Elena Rivas (2) , Juan Alvarez (2) , Josefina Perez-Zurita (2) , Mireya Goldwasser (2)

1 UCCS - Unité de Catalyse et Chimie du Solide - UMR 8181
2 CENTRO DE CATALYSIS - Petroleo y petrochimica, Escuela de chimica

An investigation of the performances in Fischer-Tropsch reaction of 1wt% M/WC(X) (M = Co, Ru; X = A, B), where A is a tungsten carbide protected by free carbon and B is a clean tungsten carbide, was carried out. Supported catalysts performances were compared to those of the parent tungsten carbides at 473 K and 20 bar. It was found that WC(A) produces mainly hydrocarbons but also 20-40% alcohols, whereas WC(B) activity is only towards linear alkanes. Before catalytic test, a reduction in pure hydrogen allows obtaining Co0 and Ru0 dispersed on layers of free carbon covering the WC core for the WC(A), and on a surface free of oxygen for WC(B). Co as Ru dispersions are improved on WC(B) compared to WC(A). A direct consequence is that Co/WC(B) has a better activity than Co/WC(A). Ru-W alloy formation could be responsible of the inobservance of a better activity for Ru/WC(B). On contrary, addition of Ru on WC(A) highly increases the activity and the production of heavy hydrocarbons. This beneficial effect, not observed with cobalt, could be attributed to a better dispersion of ruthenium on a carbon polymeric surface of WC.

Mots clés: CO Hydrogenation; Tungsten Carbide; Cobalt; Ruthenium

Domaines: Catalyse

Anne Griboval, Jean-Marc Giraudon, Ivan Twagishema, Ginette Leclercq, Maria Elena Rivas, et al.. Characterization of new Co and Ru on α-WC catalysts for Fischer-Tropsch reaction. Influence of the carbide surface state.. Journal of Molecular Catalysis, 2006, 259, pp.187-196. ⟨hal-00093728⟩