Ions are essential components in the anode-electrolyte interfacial microenvironment that significantly influence both the activity and the pathway of electrocatalytic molecular oxidation reactions. Nevertheless, most anions are generally considered inhibitory on electrocatalytic molecular (such as alcohols and amines) oxidation reactions due to their specific adsorption at the inner Helmholtz layer, negatively impacting the electrocatalytic performance. In contrast, we have found herein that fluorine ion (F-) at the outer Helmholtz layer is capable of largely elevating the electrocatalytic activity and promoting the transformation of glyceric acid to lactic acid as the main product by fluorine-hydrogen bonding with water molecules, glycerol reactants, and glyceraldehyde intermediate during the glycerol oxidation reaction. It has been revealed that these interfacial H-bondings facilitate glycerol desolvation and modulate molecular charge distribution, lower the energy barrier of proton-coupled electron transfer, improve the interfacial H-bond network connectivity, and destabilize the configuration of the glyceraldehyde intermediate. Importantly, this strategy is applicable to commonly used model catalysts, including Pt, Au, Pd, and Ni(OH)2, and offers enhanced electrolytic oxidation performances for various alcohol and amine molecules. This work provides a new perspective for the efficient electrocatalytic upgrading of alcohol and amine chemicals by establishing interfacial H-bonding.
Huang et al. (Thu,) studied this question.