Concurrently Selective Electrosynthesis of Ammonia and Glycolic Acid Over Cathodic Single‐Atom Cobalt and Anodic PdNi Alloying Catalysts

Abstract

Herein, an electrocatalytic coupling system for selective ammonia and glycolic acid production over cathodic single‐atom Co (Co─N─C) and anodic PdNi alloying nanoparticles on the carbonized cellulose (PdNi/CBC), respectively are reported. As a cathodic electrocatalyst for nitrate reduction reaction (NtrRR), the Co─N─C displays remarkably high activity, delivering an NH3 yield rate of 20.5 ± 2.7 mg h−1 mgcat.−1 with a Faradaic efficiency (FE) of 95.5 ± 2.8% at −0.5 V (vs RHE). In situ spectroscopy combined with theoretical calculations unveiled the NtrRR mechanism on Co─N4 site. As an anodic electrocatalyst for ethylene glycol oxidation reaction (EGOR), the PdNi/CBC shows a high FE of 96.6 ± 1.7% for glycolic acid (GA) production at 1.6 V (vs RHE) and robust stability of 168 h. Remarkably, a proof of concept experiment of coupling electrocatalytic NtrRR with EGOR demonstrates that only an applied potential of −0.1 V (vs RHE) is required to reach a current density of 10 mA cm−2 for co‐producing ammonia and glycolic acid. As a result, the coupled NtrRR‐EGOR system can achieve an NH3 yield rate of 6.0 ± 0.6 mg h−1 mgcat.−1 and a GA yield rate of 16.8 ± 1.7 mg h−1 mgcat.−1 at −0.7 V (vs RHE).