Exploring Furfural Catalytic Conversion on Cu(111) from Computation

The full potential energy surface of the catalytic conversion of furfural to 2-methylfuran on the Cu(111) surface has been systematically computed on the basis of density functional theory, including dispersion and zero-point energy corrections. For furfuryl alcohol formation, the more favorable step is the first H addition to the carbon atom of the C═O group, forming an alkoxyl intermediate (F-CHO +H → F-CH 2 O); the second H atom addition, leading to furfuryl alcohol formation (F-CH 2 O + H → F-CH 2 OH), is the rate-determining step. For 2-methylfuran formation from furfuryl alcohol dissociation into surface alkyl (F-CH 2 ) and OH groups, H 2 O formation is the rate-determining step (OH + H → H 2 O). Our results explain perfectly the experimentally observed selective formation of furfuryl alcohol and the equilibrium of furfural/furfuryl alcohol conversion under hydrogen-rich conditions as well as the effect of H 2 O suppressing furfural conversion. In addition, it is found that dispersion correction (PBE-D3) overestimates the adsorption energies of furfural, furfuryl alcohol, and 2-methylfuran considerably, whereas those of H 2 and H 2 O can be reproduced nearly quantitatively. Our results provide insights into Cu-catalyzed furfural selective conversion and broaden our fundamental understanding into deoxygenation reactions of oxygenates involved in the refining of biomass-derived oils.