Applied Surface Science, Vol.487, 1307-1315, 2019
Stabilization of palladium nanoparticles on chitosan derived N-doped carbon for hydrogenation of various functional groups
We report the synthesis of uniformly dispersed and stable palladium nanoparticles (Pd NPs) on N-doped graphitic carbon (N-C) derived from benign chitosan. The Pd@N-C nanocatalyst was synthesized by carbonization of Pd-chitosan complex at 800 degrees C under a nitrogen atmosphere, wherein chitosan obtained from fishery bio-waste served as carbon and nitrogen source. The as-synthesized nanocatalyst was characterized by several techniques; the elemental mapping by SEM and TEM analysis confirmed the uniform distribution of the Pd nanoparticles on the surface of N-doped carbon with an average size in the range of 2-6 nm. Temperature programmed chemisorption studies showed 32.27% Pd metal surface area available for reaction. This catalyst with low loading of active palladium metal was used for the hydrogenation of various reducible groups including > C = C < , > C C < , -NO2, -CHO and epoxides at room temperature (30 degrees C) and moderate H-2 pressure (5 bar). The catalyst offered nearly complete conversion with > 99% selectivity towards desired product. The excellent performance of the catalyst may be attributed to the dual role of N-rich carbon source which acts as a stabilization platform for palladium nanoparticles and also provides a basic environment. Furthermore, the catalyst can be easily recovered and recycled for five cycles without any significant loss in catalytic activity and selectivity.
Keywords:Heterogeneous catalyst;Palladium nanoparticles;Chitosan;N-doped graphitic carbon;Hydrogenation