Paired electrosynthesis enabled by a hydrogen atom redox-relay strategy

Abstract

Paired electrolysis is an energy- and electron-efficient approach for producing valued-added compounds at both the anode and cathode. However, its synthetic generality is hindered by the need for mutually compatible half-reaction conditions. Recognizing that common redox reactions are accompanied by the gain/loss of hydrogens, we developed a hydrogen atom redox-relay strategy to achieve spatially and temporally decoupled pairing of incompatible half-reactions. Specifically, LaNi₅-type hydrogen storage alloy electrodes serve as the hydrogen atom relay for reversible storing and releasing of hydrogen atoms during the electrooxidation of alcohols and the hydrogenation of CC, CC, CO, CN, –CN, and –NO₂ unsaturated compounds, achieving a significantly expanded scope for paired electrolysis compared to existing methodologies. This strategy achieves an excellent 0.455 mmol cm⁻² single-cycle pairing capacity and 67% utilization efficiency for hydrogen atoms. To showcase its practicality, an automated robot platform was constructed to realize uninterrupted, continuous multigram-scale paired electrosynthesis with the redox-relay electrode remaining stable for 530 hours.