Comparative study on catalytic reactivity of colloidal Ni(0)NPs and Pd(0)NPs towards semi-hydrogenation of alkynes

Abstract

In this study, nickel nanoparticles (Ni(0)NPs) and palladium nanoparticles (Pd(0)NPs) were prepared in neat glycerol under hydrogen pressure by the bottom-up approach. The formation of zero-valent metal nanospheres was evidenced by transmission electron microscopy (TEM) and powder X-ray diffraction (XRD) analyses. Regarding their catalytic behaviors, Ni(0)NPs permitted to obtain the corresponding (Z)-alkenes in the semi-hydrogenation of both internal and terminal alkynes. In contrast, over-hydrogenations of such alkynes towards the alkanes were observed over Pd(0)NPs after only 2 hours of reaction. Interestingly, the catalytic phase of Ni(0)NPs in glycerol could be recycled up to 5 times, preserving their catalytic activity and selectivity.