Optimization and reaction kinetics of catalytic transfer hydrogenation of 5‐hydroxymethylfurfural to 2, 5‐dimethylfuran over CuCoOx catalysts

From the perspective of reaction kinetics, the catalytic transfer hydrogenation (CTH) reaction of 5‐hydroxymethylfurfural (HMF) was studied in this work. Its hydrogenation product, 2,5‐dimethylfuran (DMF), was a stable and water‐insoluble biofuel alternative to gasoline. In this study, CuCoOx catalysts were used and 2‐propanol (IPA) was the hydrogen donor. The results exhibited that the HMF conversion reached 100% with the complete formation of DMF at 170 °C. Experimental and characterization results revealed that the balance of metal sites and acid sites was critical, which could inhibit the side reactions and enhance the yield of the target product. By adopting the Langmuir‐Hinshelwood‐Hougen‐Watson (LHHW) kinetic model, it was found that direct hydrogen transfer from IPA to HMF predominated over indirect transfer via H2. Moreover, the results revealed that the hydrogenolysis of BHMF to MFA was the rate‐limiting step. The kinetic study in this work is expected to provide valuable insights into the industrial optimization of the CTH reaction of HMF and lay the foundation for the study of hydrogen transfer pathways in this process.