Electrocatalytic Alcohol Oxidation to Aldehyde Through Direct Dehydrogenation Mechanism Using a High-Performance Pt/Co3O4 Catalyst.

Abstract

The electrocatalytic upgrading of low-value carbon sources has been widely regarded as a green approach for synthesizing diverse chemicals and promising route to attain carbon neutrality goals. However, according to the prevailing reactive oxygen species-mediated mechanism (ROSMM), these reactions suffer from harsh reaction conditions (strong basic electrolyte) and high energy costs (high reaction potential, especially under neutral conditions). Here, a novel electrochemical direct dehydrogenation mechanism (DDM) has been proposed. As proof-of-the-concept, Pt/Co3O4/CC catalyst has been developed to accelerate the dehydrogenation reaction for efficient upgrading of ethylene glycol to glycolaldehyde dimer. Impressively, an ultralow potential of 0.4 V versus the reversible hydrogen electrode (RHE) at a current density of 3.7 mA cm-2, a Faradaic efficiency of ∼100.0%, a selectivity of 99.0% and an extra-high productivity of 204.9 µmol h-1 cm-2 in neutral electrolyte have been obtained, which are among the highest of the state-of-the-art catalysts ever reported. Various value-added aldehydes can be obtained by similar approach. The proposed direct dehydrogenation mechanism offers novel perspectives for electrocatalyst design, reaction pathway modulation, and energy consumption reduction in the syntheses of high-value chemicals by electrocatalytic upgrading reactions.