Synergistic Mechanism for Unconventional Anodic Reaction of Aldehyde Oxidation for Hydrogen Production

Anodic reactions involving non‐faradaic process has significantly expanded the potential application of anodic oxidation half‐reactions. Metallic Cu materials can catalyze an unconventional anodic aldehyde oxidation reaction involving the non‐faradaic H2 production (AOR‐H2). AOR‐H2 has distinct advantages of ultra‐low thermodynamic potentials and high value‐added redox products, etc., but the question of exactly how reduction steps occur during AOR‐H2, is something which has long puzzled scientists. Here we illustrate the novel synergistic mechanism of non‐electrochemical/electrochemical redox steps in AOR‐H2. Aldehyde undergoes hydration, deprotonation, and spontaneous C‐H homolytic cleavage to generate H2, and then is electrochemically oxidized to form carboxylate. Decorating Cu catalysts with metallic Pt species, supported by theoretical calculations, leads to a twelvefold increase in the intrinsic activity of AOR‐H2. This work inspires researchers to develop novel cathodic and anodic reactions involving the non‐faradaic process for breaking through the limit of existing energy conversion systems.