Efficient Catalysts for the Green Synthesis of Adipic Acid from Biomass.

Green synthesis of adipic acid from renewable biomass is a very attractive goal of sustainable chemistry. Herein, we report efficient catalysts for a two‐step transformation of cellulose‐derived glucose into adipic acid via glucaric acid. Carbon nanotube‐supported platinum nanoparticles are found to work efficiently for the oxidation of glucose to glucaric acid. An activated carbon‐supported bifunctional catalyst composed of rhenium oxide and palladium is discovered to be powerful for the removal of four hydroxyl groups in glucaric acid, affording adipic acid with a 99 % yield. Rhenium oxide functions for the deoxygenation but is less efficient for four hydroxyl group removal. The co‐presence of palladium not only catalyzes the hydrogenation of olefin intermediates but also synergistically facilitates the deoxygenation. This work presents a green route for adipic acid synthesis and offers a bifunctional‐catalysis strategy for efficient deoxygenation. [ABSTRACT FROM AUTHOR]