Stable copper-based metal–organic framework-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-MOFs, HKUST-1). Cu-MOF as a support promotes 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 and 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 10 reaction cycles.