Stable Copper-Based Metal-Organic Frameworks Supported Pt-Bi Nanoparticles for Selective Oxidation of Glycerol into Dihydroxyacetone

Abstract

The selective oxidation of glycerol into high-value-added products (e.g., dihydroxyacetone, DHA) has attracted much attention. However, it is still constrained by low DHA selectivity (≤ 60%) under high glycerol conversion. Herein, we report a Pt-Bi nanoparticle catalyst supported on Cu-based metal-organic frameworks (Cu-MOF, HKUST-1). Cu-MOF as a support promotes the electron transfer from the support to Pt-Bi, and inhibits the decomposition of DHA. In situ FTIR, O2-TPD, kinetic experiments, EPR experiments, and fluorescence spectroscopy techniques show that Cu-MOF with rich microporous structure can promote oxygen adsorption and water dissociation, enhance the strong adsorption capacity of glycerol and the ability to generate abundant OH*, which is conducive to accelerating the conversion of glycerol to DHA. Consequently, Pt-Bi/Cu-MOF maintains considerable DHA selectivity (68.8%) even at a high glycerol conversion (94.2%), gaining a high yield of DHA (62.9%). Importantly, the stability of the Cu-MOF support as well as the intense metal-support interaction ensures the stability of the catalyst, which keeps superior glycerol oxidation performance after ten reaction cycles.