Metal and solvent-dependent activity of spinel-based catalysts for the selective hydrogenation and rearrangement of furfural

Abstract

The development of cost-effective heterogeneous catalysts for the selective conversion of biomass-derived platform chemicals into value-added chemicals and liquid fuels will pave the way towards the development of sustainable biorefineries. Herein, we perform in-depth optimization of the catalyst composition and experimental conditions to selectively produce three important value-added chemicals from furfural, including cyclopentanone, furfuryl alcohol, and tetrahydrofurfuryl alcohol. Results show that the Ni(10%)/CuFe₂O₄ catalyst affords cyclopentanone as a major product with >90% selectivity in water at 423 K and 1 MPa H₂. Meanwhile, switching to non-aqueous solvents, including hexane, isopropanol, toluene, and ethanol, selectively produces tetrahydrofurfuryl alcohol as a major product under identical reaction conditions. Over the Cu(10%)/CuFe₂O₄ catalyst, furfuryl alcohol is produced as a major product in water at 393 K and 1 MPa H₂. Control experiments over M/CuO, M/Fe₃O₄, and M/SBA-15 catalysts are also performed; however. these catalysts afford much lower conversion compared to the M/CuFe₂O₄ catalysts due to the higher Lewis acidity of the CuFe₂O₄ support. The physicochemical properties of these catalysts are characterized using powder XRD, HR-TEM, XPS, and pyridine FT-IR. Finally, based on the existing literature, plausible reaction mechanisms for the production of cyclopentanone, tetrahydrofurfuryl alcohol, and furfural alcohol on M/CuFe₂O₄ catalysts are proposed. The present work provides insight into the development of cost-effective and efficient catalysts for the valorization of furfural under mild conditions.