Unraveling the Mechanisms of Electrocatalytic Oxygenation and Dehydrogenation of Organic Molecules to Value‐Added Chemicals Over a Ni–Fe Oxide Catalyst

Abstract Electrocatalytic oxidative upgrading of organic molecules is a promising alternative process to water oxidation for clean hydrogen production. Yet, its underlying mechanism is still not fully understood, and suitable low‐cost electrocatalysts with good product selectivity and activity are still sought after. Here, an active NiFeO x ‐based catalyst is reported on as a general platform for the electro‐oxidative upgrading of organic molecules through oxygenation and dehydrogenation, with hydrogen coproduction. Detailed mechanistic studies unveil that C–H bond oxidation (with a bond dissociation energy BDE C–H of ≈88–96 kcal mol −1 ) is involved in the rate‐limiting step, which differs significantly from the oxygen evolution reaction mechanism. These findings show that the oxidation efficacy is linearly correlated with the BDE C–H of the molecule. Thus, the catalyst can be used as a general platform for large‐scale electro‐oxidation of various substrates through oxygenation and dehydrogenation at high current density (25 mA cm −2 ), with a good Faradaic yield. The platform's generality is further demonstrated by the selective oxidation of 5‐(hydroxymethyl)furfural into 2,5‐furandicarboxylic acid with good efficiency.