Activation-oxidation on binary CuFe oxides for highly selective electrocatalytic oxidation of benzyl alcohol to benzaldehyde

Abstract

Opting for the oxidation of benzyl alcohol instead of the anodic oxygen evolution reaction not only necessitates a lower oxidation potential for green hydrogen production, but also yields benzaldehyde. Nevertheless, overcoming the steric effect of the benzene ring, to enable effective interfacial contact, achieving the rational design of highly active sites, and ensuring highly selective oxidation pose formidable challenges. Here, we used a co-precipitation method to synthesize Cu²⁺ Fe²⁺-hydroxides. The low-valent Cu⁺ and Fe²⁺, which serve as the adsorption and active site for benzyl alcohol, respectively, in bimetallic oxides, are obtained after calcination in H₂/Ar. As a result, an anodic current density of 10 mA cm⁻² can be achieved at a potential of only 1.29 V (vs. RHE). Furthermore, the selectivity of the benzaldehyde is maintained at 100% even when the applied potential is as high as 1.8 V (vs. RHE), showing a promising direction for coupling alternative anodic reactions with green hydrogen production.