Pulse-Driven Paired Electrosynthesis of Formamide via Redox-Tuned Intermediate Management.

Renewable electricity-driven electrocatalytic systems hold promise for the sustainable formamide (HCONH 2 ) synthesis. However, a major bottleneck remains the low Faradaic efficiency (FE) and overall electron utilization inherent to current unipolar C-N coupling strategies, where substantial electron consumption at the counter electrode severely limits system efficiency. Here, we propose a redox-tuned paradigm ( A red + B oxi → C ) through a pulsed paired electrosynthesis strategy. Using an atomically ordered CuPd catalyst with CH 3 OH and NO 2 - as feedstocks in an undivided cell, HCONH 2 is simultaneously produced at both electrodes under optimized pulse conditions with alternating change in potential periodically ( E a = 1.3 V, t a = 10 s; E c = -0.7 V, t c = 10 s). This system achieves an FE of 85.6% for HCONH 2 at a current density of 81.5 mA cm -2 , with a yield of 263.3 μmol·h -1 ·cm -2 . The FE is higher than those reported to date. Mechanism studies reveal that pulsed operation creates a periodically switching cathode/anode environment. This enables the ordered CuPd catalyst to function sequentially as a reduction site (converting NO 2 - to *NH 3 ) during cathodic pulses and as a co-oxidation site (converting *NH 3 to *NH 2 along with CH 3 OH to *HCOH) during anodic pulses, thereby driving efficient C-N bond coupling to form HCONH 2 . Techno-economic analysis further confirmed the significant industrial potential of this strategy in the future renewable energy market.