Highly Porous Nitrogen- and Phosphorus-Codoped Graphene: An Outstanding Support for Pd Catalysts to Oxidize 5-Hydroxymethylfurfural into 2,5-Furandicarboxylic Acid

The oxidation of 5-hydroxylmethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a sustainable and promising route to bioderived aromatic polyesters. So far, the design of catalyst has been restricted by the unclear working mechanism, and thus most of the supported noble metal catalysts cannot provide a remarkable reaction rate under atmospheric pressures and room temperature. Here we report a new mechanistic insight into the structure–performance correlation of graphene-supported Pd catalysts. It is demonstrated that a new kind of highly porous nitrogen- and phosphorus-codoped graphene sheets (HPGSs) will enhance the fraction of surface Pd2+ species, which plays a determining role to reduce the activation energies of both HMF conversion and FDCA formation. Such a support effect may assist in developing highly active catalysts for FDCA synthesis under mild conditions.