Application of magnetically separable silica aerogel-supported palladium catalyst in the hydrogenation of aromatic nitro compounds

Palladium nanocatalyst has been prepared via sonication-induced reductive deposition for the hydrogenation of nitro groups, tested in the two industrially most significant nitro compound hydrogenation processes: nitrobenzene hydrogenation to aniline and 2,4-dinitrotoluene to 2,4-toluene diamine. The main feature of the catalyst beside the fact that it is well usable for both reactions with high efficiency (~ 99% at 60 °C and 20 bar with 192 substrate-to-palladium ratio), the paramagnetic properties owing to the presence of magnetite (20.9 wt%), which enables separation via magnetic field (5.7 A m 2 k g −1 ). This feature provides further alternative possibility for both laboratory and industrial applications. Furthermore, the use of AEROSIL 200 (fumed amorphous silica) with a straightforward magnetite preparation method provides a cost-efficient support with advantageous properties for a promising catalyst.