Defect Engineering Modulates the Edge Microenvironment of MoS ₂ for Significantly Enhanced Selective Electrocatalytic Hydrogenation of 5-Hydroxymethylfurfural

Electrocatalytic hydrogenation (ECH) offers a sustainable route for chemical production under ambient conditions; however, it faces challenges including intense competition from the hydrogen evolution reaction (HER) and reliance on precious metal-based electrocatalysts. Herein, we report, for the first time, the integration of molybdenum disulfide (MoS2) with defect engineering to develop highly efficient, noble-metal-free electrocatalysts. This defect control strategy effectively modulates the electronic structure and increases the specific surface area, thereby promoting the ECH of biomass-derived oxygenates while suppressing H2 evolution. Defect-rich molybdenum disulfide nanosheets (denoted as D-MoS2) successfully catalyze the hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)furan (BHMF). At a potential of −0.2 V (vs RHE), D-MoS2 achieves a Faradaic efficiency (FE) of 93% for BHMF, a production rate of 0.69 mmol·cm–2·h–1, and a conversion of 72%, while the FE for H2 remains as low as 8%. The BHMF production rate reaches a maximum of 0.85 mmol·cm–2·h–1 at −0.3 V (vs RHE). These superior performances are attributed to enhanced chemical adsorption and an increased specific surface area. Specifically, the adsorption of H* intermediates and HMF molecules at the edge sites of D-MoS2 is synergistically strengthened, accelerating the surface reaction steps following the Langmuir–Hinshelwood mechanism. This work opens up new avenues for the design of advanced electrocatalysts for electrochemical synthesis applications.