Theoretical Insights into Facet-Dependent Activity and Selectivity of Cu Catalysts in Electrochemical Furfural Reduction

Electrochemical hydrogenation of furfural (ECHFF) is a promising and ecofriendly strategy for the conversion of biomass-derived compounds into high-value-added chemicals or fuels such as furfuryl alcohol (FA) and 2-methylfuran (MF). Herein, the adsorption behavior and reaction mechanism of furfural (FF) converted to FA and MF on Cu electrocatalysts were systemically investigated, and a screening factor for the ECHFF electrocatalyst was proposed. First, it is demonstrated that Cu(211) is the most active facet compared to Cu(110), Cu(100), and Cu(111). Then, the ECHFF process was revealed, and the favorable reaction path is FCHO + * → FCH2O* → FCH2OH* → FCH2* + HO* → FCH3* + HO* → FCH3* + H2O* → FCH3 + H2O. Finally, the C–O bond-breaking barrier of FCH2OH* and the desorption energy were chosen to screen the catalysts for the particular products FA and MF. It is found that Cu(110), Co(001), and Fe(110) have higher selectivity of MF, while Ag(111), Au(111), and Cu(111) have higher selectivity of FA. This work could assist in the catalyst design of ECHFF in future experiments and lay a theoretical foundation for biomass electrocatalytic conversion.