Abstract Ir (0) nanoparticles with 2.3±0.4 nm in diameter prepared by simple reduction of [Ir (cod) Cl] 2 in 1-n-butyl-3-methylimidazolium hexafluorophosphate ionic liquid constitute a simple, efficient and recyclable catalytic system for the solventless or biphasic hydrogenation of ketones under mild reaction conditions.
