Unassisted Electrocatalytic Hydrogenation Coupled With Aldehydes Oxidation on Bifunctional Pd-Cu Synergistic Sites

Paired electrolysis enhances energy utilization efficiency by coupling anodic oxidation with cathodic reduction reactions, enabling the simultaneous production of high-value chemicals. However, achieving the transition from electricity consumption to electricity generation in paired electrolysis remains a huge challenge due to mismatched potentials of anodic and cathodic reactions and lack of highly efficient active sites. Herein, we designed an electrochemical system that couples cathodic hydrogenation of various unsaturated compounds with anodic aldehydes oxidation reactions at a synergistic Pd-Cu bifunctional site. The paired hydrogenation and oxidation reactions were demonstrated to produce valuable products at both electrodes simultaneously without electrical energy input. Experimental studies and theory calculations indicate a Pd-Cu cooperative mechanism, which optimizes hydrogen transfer kinetics in both hydrogenation and oxidation reactions. Specifically, the Pd site promotes water dissociation to generate active hydrogen, which then spillover to the adjacent Cu site to catalyze hydrogenation, while the Pd site modulates the electronic structure of the Cu site, promoting C─H bond cleavage and facilitating H₂ generation during aldehydes oxidation. This study demonstrates that precise catalyst design and reaction system optimization can achieve efficient synergy between oxidation and reduction reactions in paired electrolysis, offering new insights and technological pathways for electrochemical synthesis of high-value chemicals.