Selective Electrochemical Oxidation of p-Xylylene Glycol Coupled with the Hydrogen Evolution Reaction via a Continuous Flow Strategy

Abstract

Catalytic oxidation of alcohols to their corresponding aldehydes and ketones plays a fundamental role in many industries, but conventional strategies suffer from high costs, harsh reaction conditions, and low energy efficiency. Here, we combine the p-xylylene glycol oxidation with the hydrogen evolution reaction via an I–/I3 – redox mediator in an electrochemical flow system where inexpensive graphite felt (GF) is utilized as electrodes. In comparison to traditional chemical oxidation, the electrochemical flow synthesis via the mediator I–/I3 – could offer an outstanding p-hydroxymethyl benzaldehyde selectivity of 96.5% and a Faradaic efficiency of 84.8%. Besides, we realize the gram-scale synthesis of p-hydroxymethyl benzaldehyde at the current density of 25 mA/cm2 with low energy consumption because of the prepared catalytically efficient GF-Cu7S4 and GF-Pt electrodes. We explore different substrates and observe the flexible adaptability of our proposed flow synthesis strategy, demonstrating its potential for industrial applications.