Oriented Au nanoplatelets on graphene promote Suzuki-Miyaura coupling with higher efficiency and different reactivity pattern than supported palladium

- Kinetic studies showed that the reactivity order is the result of the poisoning effect of halides for Au.
- The poisoning effect of Au is much higher for I− than Br− and much higher than for Cl−, due to adsorption.
- This strong iodide adsorption leading to Au catalyst deactivation was predicted by DFT calculations of Au clusters.
- Au‾/fl-G are about one order of magnitude more efficient than small Au nanoparticles (4-6 nm) obtained by the polyol method supported on graphene.
- Au‾/fl-G are about three orders of magnitude more efficient than Pd nanoparticles supported on graphene.

Facet 1 1 1 oriented Au nanoplatelets (20-40 nm wide, 3-4 nm height) grafted on graphene (Au‾/fl-G) are about three orders of magnitude more efficient than Pd nanoparticles supported on graphene to promote Suzuki-Miyaura coupling. In contrast to Pd catalysis, it is shown here that the product yields in Suzuki-Miyaura coupling catalyzed by Au nanoparticles follow the order chlorobenzene > bromobenzene > iodobenzene. Kinetic studies show that this reactivity order is the result of the poisoning effect of halides for Au that is much higher for I− than Br− and much higher than for Cl−, due to adsorption. This strong iodide adsorption leading to Au catalyst deactivation was predicted by DFT calculations of Au clusters. Au‾/fl-G are about one order of magnitude more efficient than small Au nanoparticles (4-6 nm) obtained by the polyol method supported on graphene. Our results can have impact in organic synthesis, showing the advantage of Au‾/fl-G as catalyst for Suzuki-Miyaura couplings.

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