Cobalt-nickel bimetallic Fischer-Tropsch catalysts: A combined theoretical and experimental approach

The low temperature Fischer-Tropsch (FT) synthesis reaction is commercially performed on either Fe- or Co-based systems, while Ni-based systems are not considered due to a poor selectivity profile. This study focuses on alternative bimetallic catalytic materials for FT in which both Co and Ni are present. Co-Ni based alloys have been identified as a possible FT synthesis catalyst through a separate, DFT based computational chemistry screening approach of various bimetallic alloys based on the similarity of their underlying calculated electronic structures to that of Co. Based on this screening result and a cost filtering, several supported catalysts have been prepared with varying Co:Ni ratios. These catalysts have been characterised with various techniques (TPR, EDS, EELS, Magnetic measurements) to assess whether these catalysts indeed show Co-Ni alloy formation. These materials were also tested for FT synthesis activity, showing that the selectivities of the Co-Ni alloys are similar to that of pure Co up to a nickel content of 25%. It was also concluded that the computational screening approach can be used to execute predictive metal screening.