Continuous Furfuryl Alcohol Production via Coupled Dehydrogenation-Hydrogenation over Supported Cu and Au Catalysts: A Consideration of Hydrogen Generation and Transfer

We have investigated the continuous (P = 1 atm, T = 453 K) coupled dehydrogenation/hydrogenation of 2-butanol/furfural for the simultaneous production of 2-butanone and furfuryl alcohol. A series of oxides (Al ₂O ₃, ZrO ₂, SiO ₂, TiO ₂ and CeO ₂) were used to support nano-scale Cu (mean size 2.2–2.8 nm from STEM) and tested in the dehydrogenation of 2-butanol. All the supported Cu catalysts promoted exclusive formation of the target 2-butanone. Hydrogen production was shown to correlate with the Lewis basicity of the oxide support and the highest rate was recorded for Cu/CeO ₂. Conventional furfural hydrogenation (using an external supply of hydrogen) over ceria supported Au (mean size =3.5 nm) was fully selective to furfuryl alcohol where less than 1 % of the hydrogen supplied was utilised. Under the same reaction conditions, exclusive formation of 2-butanone and furfuryl alcohol and higher hydrogenation rate was achieved in the coupled process over physical mixtures of Au/CeO ₂+Cu/Oxide (in N ₂) where Cu → Au hydrogen transfer was favored by coke (from TGA). The combination Au/CeO ₂+Cu/CeO ₂ delivered a 70-fold higher hydrogenation rate, full H ₂ utilisation and 215 times lower E-factor. Our results demonstrate in situ hydrogen generation via dehydrogenation as a sustainable alternative hydrogenation route to valuable products.