Nitrile hydration to amide in water: Palladium-based nanoparticles vsmolecular catalyst

The catalytic performance of small Pd-nanoparticles (NPs) (2.0 nm), partially covered bychemisorbed oxygen atoms, and of Pd-acetate, both stabilized by 2,2-bipyridine-end functional-ized poly(ethyleneglycol) monomethylether was compared in the selective hydration of nitriles toamide in water under mild reaction conditions (353 K). Regardless of the nitrile substrate employed,the Pd-NP-based catalyst showed much higher normalized TON-values (i.e. refereeing to the amount ofsurface Pd atoms) compared to the Pd(II) macrocomplex, as far as the first catalytic run was considered.Deactivation of the Pd-NP-based catalyst was significant due to the formation of a hydroxide-waterlayer on the NPs' surface.