Rhodium(0) nanoparticles supported on nanotitania as highly active catalyst in hydrogen generation from the hydrolysis of ammonia borane

Abstract

Rhodium(0) nanoparticles supported on the surface of titanium dioxide (Rh(0)@TiO₂) were in situ generated from the reduction of rhodium(III) ions impregnated on nanotitania during the hydrolysis of ammonia borane. They were isolated from the reaction solution by centrifugation and characterized by a combination of advanced analytical techniques. The results show that (i) highly dispersed rhodium(0) nanoparticles with sizes in the range 1.3–3.8 nm were formed on the surface of titanium dioxide, (ii) Rh(0)@TiO₂ shows high catalytic activity in hydrogen generation from the hydrolysis of ammonia borane with a turnover frequency value up to 260 min⁻¹ at 25.0 ± 0.1 °C, (iii) the results of kinetic studies on the hydrogen generation from the hydrolysis of ammonia borane were also reported including the activation energy of 65.5 ± 2 kJ mol⁻¹ for this reaction.