MoS₂-catalyzed selective electrocatalytic hydrogenation of aromatic aldehydes in an aqueous environment

The development of an active earth-abundant metal electrocatalyst for biomass-derived organic materials valorization can greatly benefit the growth of a sustainable biorefinery. Herein, we report a transition metal dichalcogenide catalyst, MoS₂, as a great electrocatalytic hydrogenation catalyst in converting a highly versatile platform chemical furfural to furfuryl alcohol, with over 82.4% yield and 92.1% selectivity, and its catalytic performance surpassed those of 11 other base metal electrocatalysts. The durable layer of 1T-rich MoS₂ was fabricated on a carbon cloth support via a novel seeded-solvothermal deposition, followed by a thermal treatment. Reaction mechanistic investigation via underpotential hydrogen desorption (H_UPD) studies and substrate scope expansion showed that MoS₂ delivered the mechanism in a stage-wise manner, where the reduction of the carbonyl occurred to yield a radical intermediate in the vicinity of the MoS₂ catalyst, followed by an abstraction of a surface adsorbed hydrogen (H_ads). The conversion of reactants benefited from the presence of electron-withdrawing substituents, and the product selectivity was inert to the influence of the substituents. The MoS₂ can be prepared easily through electrocatalytic and solvothermal deposition. The resulting catalyst layer demonstrated great stability throughout the repeated application in bulk electrolysis.