Surfactant‐Stabilized Aqueous Iridium(0) Colloidal Suspension: An Efficient Reusable Catalyst for Hydrogenation of Arenes in Biphasic Media

Aqueous suspensions of iridium nanoparticles produced by the chemical reduction of IrCl 3 assisted by sonication, in the presence of N , N ‐dimethyl ‐N ‐cetyl‐ N ‐(2‐hydroxyethyl)ammonium chloride salt as surfactant, have shown an efficient activity for the catalytic hydrogenation of various aromatic derivatives in biphasic media under mild conditions. These nanocatalysts can be reused for further runs with a total conservation of activity and provided significant catalytic lifetime for anisole hydrogenation in pure water with 3000 total turn‐over (TTO).