Janus Palladium Membrane Electrode Enables Competent Hydrodehalogenation via Hydride Transfer

Efficient and selective electrochemical hydrodehalogenation of organic halides remains a significant challenge in electrocatalysis due to competing side reactions, low Faradaic efficiency, and stringent solubility requirements. Herein, we introduce a design of Janus palladium membrane electrode (J-Pd_m) that enables the direct generation and transfer of hydride species from water reduction in a dual-cell configuration. This design facilitates heterogeneous hydride transfer in an aprotic environment, achieving rapid reaction rate and superior Faradaic efficiency compared to conventional electrochemical hydrogenation systems and traditional electrochemical palladium membrane reactors. Notably, J-Pd_m efficiently catalyzes the hydrodehalogenation of unactivated alkyl halides, a challenging transformation that suffers from poor efficiency in traditional electrocatalytic systems. Furthermore, J-Pd_m enables the site-selective deuteration of pharmaceutical molecules, as demonstrated in the gram-scale synthesis of deuterated ibuprofen using D₂O as the deuterium source. This work demonstrates J-Pd_m as a powerful and versatile platform for electrocatalytic hydrogenation, hydrogenolysis, and isotopic labeling, offering a competent alternative to conventional electrochemical strategies and exhibiting broad industrial and pharmaceutical applications.