Scalable Electrosynthesis of Formamide through C−N Coupling at the Industrially Relevant Current Density of 120 mA cm−2

Abstract

AbstractThe scalable and durable electrosynthesis of high‐valued organonitrogen compounds from carbon‐ and nitrogen‐containing small molecules, especially operating at a high current density, is highly desirable. Here, a one‐pot electrooxidation method to synthesize formamide (HCONH2) from methanol and ammonia over a commercial boron‐doped diamond (BDD) catalyst is reported. The formamide selectivity from methanol and formamide Faradaic efficiency (FE ) achieve 73.2 % and 41.2 % at the current density of 120 mA cm−2 with high durability. The C−N bond originates from the nucleophilic attack of ammonia on an aldehyde‐like intermediate. Impressively, an 8 L electrolyzer is employed for the pilot plant test over a 2200 cm2 BDD electrode, which exhibits 33.5 % FE at 120 mA cm−2 (current: 264 A) with a yield rate of 36.9 g h−1, demonstrating the potential of this technique for large‐scale electrosynthesis of formamide.