Fe Electron Center Local Regulation of CoFe-Layered Double Hydroxides Nanosheets for Enhancing the Electrocatalytic Oxidation of Benzyl Alcohol

Replacing sluggish oxygen evolution reaction (OER) with electrocatalytic oxidation (ECO) of alcohols was a promising hotspot due to its advantages of requiring low potential, inhibiting mixing of gases, and forming value-added products. In the ECO of alcohols process, Fe electron centers of Fe-based layered double hydroxides (LDHs) can regulate the d band of LDHs overlap, optimize the active local structure of LDHs, and then enhance the electrocatalytic oxidation performance. In this work, CoxFey-LDHs nanosheets with different ratios of Co/Fe were prepared for selective ECO of benzyl alcohol (BA) to benzoic acid (BAC). Comprehensive characterizations revealed that the adjustment of bandgap and OH species adsorption of CoxFey-LDHs resulted in the appropriate thermodynamic driving force, which improved the electrical conductivity of CoxFey-LDHs and enhanced their ECO of BA. Especially, the as-prepared Co3Fe1-LDH showed intriguing electrocatalytic activity and only required a potential of 1.51 V (vs. RHE) to achieve a total current density of 50 mA cm-2 in alkaline solution containing 10 mM BA with a conversion (96.79 %) of BA and selectivity (94.93 %) of BAC, which was 60 mV lower than that of OER. After six cycles, Co3Fe1-LDH still achieved 94.74 % conversion of BA and 92.10 % selectivity of BAC without significant degradation. The Co3Fe1-LDH exhibits excellent ECO of BA performance in alkaline owing to the Fe electron centers of the Fe-based LDHs catalysts can regulate the d band of LDHs overlap, optimize the active local structure of LDHs, and then enhance the electrocatalytic oxidation performance.image