Fischer-Tropsch Synthesis, Ru nanoparticles, organometallic approach, hydrogenation of CO
The development of more active and/or selective catalysts for industrial application of the Fischer Tropsch Synthesis (FTS) process is still an ongoing field of research.In this context, Ru nanoparticles that are expected to provide more efficient and selective catalytic performance appear as a system of choice to investigate surface chemistry studies. With the aim to apprehend the influence of the metal core size and of the surface ligand of NPs in model FTS, we prepared a set of organometallic RuNPs namely Ru-PVP(1.3 nm), Ru-dppb (1.9 nm) and Ru-heptanol-dppb(3.1 nm)and studied their surface reactivity by following the hydrogenation of CO into hydrocarbons (olefins and paraffins) using a combination of techniques like gas phase and solid state NMR, MS and IR. The obtained results evidence that the size increase of the metal core does not affect significantly the catalytic properties of the RuNPs in a FTS model reaction (comparable conversion and selectivity are obtained) but that ligand has a crucial role in directing the catalytic reaction. The major result is the evidencing of the high influence of the surface modification of RuNPs by introducing a ligand, namely a diphosphine in the present case (dppb).