Unlocking efficient electrocatalytic oxidation of fatty alcohol via self-promoted hydrophobic interfacial microenvironment

Electrocatalysis offers a promising solution for the oxidative valorization of fatty alcohols, showcasing reaction mildness and sustainability. However, the intrinsically low solubility of fatty alcohols in aqueous electrolyte presents severe mass transfer barriers, thus impeding the efficiency of electrocatalytic oxidation processes. In this study, we develop an electrolyte engineering strategy that avoids exogenous additives. By utilizing the amphiphilic fatty acid anions, we construct a “self-promoted” hydrophobic interfacial microenvironment. This design significantly enhances the oxidation rate of fatty alcohols on gold electrocatalysts while simultaneously ensuring high-purity products. Specifically, the addition of potassium octanoate (KC8) into 1 mol L -1 KOH results in a 3-4 fold increase in terms of current density and productivity for octanol oxidation, underscoring substantial practical potential. Mechanistic studies reveal that KC8 modifies the electrical double layer structure, effectively repelling interfacial water and disrupting the hydrogen bond network, thereby enhancing interfacial hydrophobicity. The hydrophobic microenvironment subsequently promotes the enrichment of octanol reactants at the interface, leading to improved adsorption coverage on the electrode. The “self-promoted” strategy established in this work represents a cost-effective method for interfacial microenvironment modulation, offering inspiration for the development of efficient organic electrocatalytic processes involving hydrophobic reactants. A “self-promoted” strategy employs fatty acid anions to construct interfacial hydrophobic environments for efficient electrocatalytic oxidation of fatty alcohol. • Electrocatalysis enables green and mild oxidation of fatty alcohols to fatty acids. • Fatty acid anions act as interfacial modifiers, eliminating exogenous additives. • The self-promoted strategy boosts current density and production rate by 3–4 fold. • Fatty acid anions form hydrophobic microenvironment that enriches reactants