Electrocatalytic Oxidation of Primary Alcohols at the Triple-Phase Boundary in an Anion-Exchange Membrane Reactor with Nickel, Cobalt, and Iron Catalysts

Transition metals, such as nickel (Ni), cobalt (Co), and iron (Fe), exhibit catalytic activity for electrochemical oxidation under basic conditions. In this study, we demonstrate the highly selective electrochemical oxidation of primary alcohols to aldehydes using Ni, Co, and Fe catalysts in an anion-exchange membrane (AEM) reactor. Our findings indicate that non-noble metal catalysts can be utilized for the electrocatalytic oxidation of primary alcohols by leveraging basic conditions that do not corrode these metals. In addition, we prepared binary metal alloys and oxide catalysts and investigated their catalytic abilities for alcohol oxidation. The results demonstrate that controlling the oxygen evolution reaction potential through the composition ratio of the binary catalyst and avoiding interference with the desired alcohol oxidation are crucial for increasing the yield of the oxidation products. Furthermore, despite the basic nature of the reaction sites, the electrocatalytic oxidation of primary alcohols selectively yielded the corresponding aldehydes, which was attributed to the unique triple-phase interfacial reaction sites in the AEM reactor.