Highly stable Pt nanoparticle catalyst supported by polyphenol-grafted collagen fiber and its catalytic application in the hydrogenation of olefins

BACKGROUND: Collagen fiber (CF) is a potential biopolymer support for preparing Pt nanoparticle catalyst. Previous work has shown that the interaction between CIF and platinum group metals is not strong enough to fully immobilize these metals. Therefore, epigallocatechin-3-gallate (EGCG), which contains multiple orthophenolic hydroxyls, was grafted onto the surface of CF in order to enhance the immobilization of Pt nanoparticles on CF. The methods of preparing EGCG-grafted CF (EGCG-CF) and EGCG-CF supported Pt nanoparticle catalyst (Pt-EGCG-CF) were optimized. The catalytic activity and selectivity of Pt-EGCG-CF for hydrogenation of typical olefins were investigated. RESULTS: Scanning electron microscopy displayed the ordered fibrous morphology of Pt-EGCG-CF. The presence of EGCG grafted on the CF surface and the coordinate interaction of EGCG and Pt were confirmed by X-ray photoelectron spectroscopy analysis. X-ray diffraction and transmission electron microscopy analyses showed that Pt nanoparticles with diameter 1-3 nm were uniformly dispersed on the outer surface of CF. Hydrogenation of olefins catalyzed by Pt-EGCG-CF was conducted under mild conditions. This heterogeneous catalyst exhibited outstanding activity and nearly 100% selectivity for the hydrogenation of C=C double bonds. Moreover, this catalyst presented satisfactory reusability and storage stability in air. CONCLUSION: An efficient method has been established to prepare a highly active, selective and stable Pt nanoparticle catalyst for the hydrogenation of olefins using EGCG-grafted CF as a bio-support. (C) 2009 Society of Chemical Industry