Ultraconjugated Electron–Proton Transfer Mechanism in the Product Selectivity-Controllable Electrocatalytic Oxidation of Binary Primary Alcohols

Controllable conversion of reactants to desired products in electrocatalytic reactions is of inherent significance but faces fundamental challenges, such as the oxidation upgrading of polyhydric alcohols. To date, the reaction mechanism, especially the selectivity-determining step (SDS), is still unclear in electrocatalytic alcohol oxidation. Herein, a unique ultraconjugated electron-proton transfer mechanism has been proposed to elucidate the oxidation behavior of the far-end hydroxyl groups from the catalyst surface in the electrocatalytic oxidation of binary primary alcohols (BPAs) as a paradigm. It has been revealed that the desorption/oxidation of hydroxy acids is the SDS in the electrocatalytic oxidation of ultraconjugated structure-containing BPAs according to the proposed mechanism. Accordingly, the selectivity to target products can be effectively and elaborately regulated by, for example, altering the electrochemical reaction parameters such as potentials. This study clarifies the critical role of the inherent molecular structure of reactants in determining the final product distribution, therefore not only helping to gain useful knowledge for the controlled electrocatalytic conversions of polyhydric alcohols but also providing new insights into product distribution regulations in the electrocatalytic conversions of a broad spectrum of complex organic molecules containing conjugated structures.