Enhanced Selective\nOxidation of Glycerol to Dihydroxyacetone\nover Pt@Sn-MFI Zeolites

Supported Pt nanoparticles (NPs) exhibit excellent activity\nfor\nthe selective oxidation of glycerol (GL) derived from biodiesel production\nto high-value dihydroxyacetone (DHA). However, their selectivity to\nDHA is not satisfactory due to the preferential oxidation of the primary\n−OH in GL. In this study, Pt@Sn-MFI with ∼4.0 nm Pt\nNPs and different Si/Sn ratios were synthesized by an <i>in situ</i> encapsulation strategy. The optimized Pt@Sn-MFI-80 catalyst presents\na 74.8% selectivity to DHA with a GL conversion of 43.5% at 60 °C.\nOur experiments and density functional theory (DFT) calculations indicated\nthat the excellent selectivity was ascribed to the synergistic effect\nbetween Pt and Sn-MFI. Sn-MFI turned Pt NPs into an electronic-poor\nstate so that suppressed further oxidation of glyceraldehyde (GLD);\nthen, Sn-MFI triggered isomerization of GLD to generate DHA. The core–shell\nstructure not only guaranteed an intimate contact between Pt and Sn-MFI\nbut also enhanced the stability of the active Pt NPs.