The use of microwave irradiation for the easy synthesis of graphene-supported transition metal nanoparticles in ionic liquids

Stable ruthenium or rhodium metal nanoparticles were supported on chemically derived graphene (CDG) surfaces with small and uniform particle sizes (Ru 2.2 ± 0.4 nm and Rh 2.8 ± 0.5 nm) by decomposition of their metal carbonyl precursors by rapid microwave irradiation in a suspension of CDG in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate. The graphene-supported hybrid nanoparticles were shown to be active and could be re-used at least 10 times as catalysts for the hydrogenation of cyclohexene and benzene under organic-solvent-free conditions with constant activities up to 1570 mol cyclohexane × (mol metal) −1 × h −1 at 4 bar and 75 °C.