Sonochemical One-Pot Synthesis of Carbon Nanotube-Supported Rhodium Nanoparticles for Room-Temperature Hydrogenation of Arenes

Fine rhodium (Rh) nanoparticles with an average diameter of 2.5 +/- 0.7 nm can be deposited uniformly on surfaces of carboxylate functionalized multiwalled carbon nanotubes (MWNTs) by a simple one-step sonochemical method in an ethanol solution containing RhCl3 and an organic reducing agent borane morpholine complex (C4H12BNO). The carbon nanotube (CNT)-supported Rh nanoparticles are highly active and reusable catalysts for hydrogenation of benzene and its derivatives at room temperature. Complete ring saturation of polycyclic aromatic hydrocarbons (PAHs) can be achieved under mild hydrogenation conditions using the Rh/MWNT catalyst that can not be done by commercially available Rh nanocatalysts. This one-pot synthesis technique provides a simple and rapid way of making highly active and recyclable CNT-supported nanocatalysts for low-temperature hydrogenation reactions.