Morphology-controlled Pd nanocrystals as catalysts in tandem dehydrogenation-hydrogenation reactions

A facile synthetic protocol was used to prepare morphology controlled Pd nanocrystals with spherical and cubic shapes of different sizes. Carbon-supported catalysts were prepared from the as-synthesised nanocrystals and their catalytic ability in a tandem dehydrogenation/hydrogenation reaction composed by the dehydrogenation of ammonia borane, serving as a hydrogen source, and the subsequent hydrogenation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) was assessed. The catalytic performance was strongly dependent on the nanocrystals morphology and the spherical nanoparticles with an average size of 5.5 nm displayed the best performance among investigated. Synopsis: Colloidal synthesis was used to prepare morphology-controlled Pd nanocrystals with spherical and cubic shapes and different sizes. They were loaded on a carbon support and tested in a tandem dehydrogenation/hydrogenation reaction based on the hydrogen production from and hydrogenation of 4-nitrophenol. The catalytic activity was dependent on the nanocrystal morphology.