Synergistic effects of PtFe/CeO2 catalysts afford high catalytic performance in selective hydrogenation of cinnamaldehyde

Abstract

Selective hydrogenation of unsaturated aldehydes remains a grand challenge in controlling chemoselectivity up to now. We synthesized a series of PtFex/CeO2 catalysts, which were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) as well as temperature-programmed-reduction by hydrogen (H2-TPR). The catalytic performance of PtFex/CeO2, including cinnamaldehyde (CAL) conversion and selectivity toward cinnamyl alcohol (COL), is improved remarkably by introduction of Fe species in the Pt particles in the selective CAL hydrogenation under mild conditions. XPS results indicate that the electron transfer from Fe to Pt promotes CAL adsorption, resulting in the enhanced CAL conversion. And the COL selectivity is improved by CAL adsorption via an interaction of CO group with surface oxygen defect sites because of interaction between PtFe and CeO2 support. In all, this study may provide some hints to design efficient nano Pt particles for the selective hydrogenation.