New, innovative methods for the large scale preparation of nanosized metal catalysts and their use in selective hydrogenations

Nanomaterials are very important today because they are employed in a great number of different industrial sectors. In particular, nanostructured metal catalysts have attracted an intense interest because they allow a crucial improvement of the catalytic performances. In this field, many synthetic methods have been reported, but all these present several drawbacks that limit their application on industrial scale. Now we have patented a simple and cheap process for the large scale preparation of nanosized metal catalysts working in a low boiling alcohol. The prepared nanocatalysts are characterized by TEM, SEM, elemental analysis, FT-IR spectroscopy and XPS. This method has been successfully adopted for the preparation of gold, palladium and ruthenium nanocatalysts. This process enables to reach a good control of the metal particles dimensions and morphology with an absolute reproducibility. The ruthenium nanocatalysts are particularly efficient in different chemoselective reactions, such as the hydrogenations of benzene to cyclohexene and of phenol to cyclohexanone. On the other hand, palladium nanocatalysts were tested in the hydrogenation of cyclohexene as well as of benzaldehyde to benzyl alcohol, showing excellent performances in terms of activity and selectivity, good reproducibility, recyclability and thermal stability.