Heterogeneous Pt-Reox/C Catalyst For Making Renewable Adipates In One Step From Sugar Acids

Renewable adipic acid is a value-added chemical for the production of bioderived nylon. Here, the one-step conversion of mucic acid to adipates was achieved in high yield through deoxydehydration (DODH) and catalytic transfer hydrogenation (CTH) by a bifunctional Pt-ReOx/C heterogeneous catalyst with isopropanol as solvent and reductant. The Pt-ReOx/C catalyst is reusable and was regenerated at least five times. The catalyst exhibits a broad substrate scope of various diols. Spectroscopic studies of Pt-ReOx/C revealed Re-VII and Pt-0 as the relevant species for DODH and CTH, respectively. Isotope labeling experiments support a mono-hydride mechanism for CTH over Pt. This work demonstrates a reusable bifunctional catalyst for a one-step valorization of sugar acids to a practical monomer, which opens the door to multifunctional catalysis streamlining valorization of biomass-derived molecules.