Preparation of highly active heterogeneous Au@Pd bimetallic catalyst using plant tannin grafted collagen fiber as the matrix

Au@Pd bimetallic nanoparticles (NPs) catalysts were synthesized by a seeding growth method using bayberry tannin grafted collagen fiber (BT-CF) as the matrix. In this method, Au3+ was first reductively adsorbed onto BT-CF to form Au NPs, and then they serve as the seeds for the over growth of Pd shell. The morphology of BT-CF-Au@Pd catalyst was observed by TEM and SEM, and the core-shell structure of the Au@Pd was confirmed by EDS and XRD. It was found that the as-prepared BT-CF-Au-9@Pd-3 catalyst showed excellent synergy effect in liquid-phase hydrogenation of cyclohexene, whose reaction time was three times faster than that catalyzed by BT-CF-Pd catalyst under the same conditions. Meanwhile, the BT-CF-Au-9@Pd-3 catalyst could be re-used four times without significant loss of activity. In the fourth run, the substrate conversion was still as high as 92.70%, much better than that by using commercial Pd/C catalyst (42.60%). Additionally, BT-CF-Au-9@Pd-3 catalyst exhibited high hydrogenation activity to various alkenes and nitro-compounds. For example, the TOF of allyl alcohol, styrene and nitrobenzene hydrogenations reached 10,980, 14,732 and 1379mol mol(-1) h(-1), respectively. (c) 2012 Published by Elsevier B.V.