Harnessing\nIron Nitride Matrices through Incorporated\nCu-Based Moieties for Chlorine Evolution Reaction

Chlorine evolution\nreaction (CER) is a critical reaction in many\nprocesses, such as chlor-alkali electrolysis and electrochemical wastewater\ntreatment. The scarce and high-cost iridium and ruthenium content\nof benchmark dimensionally stable anodes (DSA) coupled with subpar\nactivities at commercially relevant current densities (≥150\nmA cm<sup>–2</sup>) opens the door for additional material\ngroups to be investigated. Herein, a highly porous, conductive, and\nchemically resilient trigonal ε-Fe<sub>3</sub>N-based electroactive\ncatalytic substrate is used toward CER in industrial acidic brine\n(4.0 M NaCl, pH = 2) environments. Consecutive hydrothermal-nitridation\nsteps were fine-tuned for homogeneous dispersion of Cu<sub>3</sub>N moieties atop FeN, which exhibited a similar overpotential to DSA\nat a commercially relevant current density. An approximately 562 mV\noverpotential was needed to sustain a current density of 200 mA cm<sup>–2</sup> for 75 h of chronoamperometric conditions. Moreover,\nonline GC measurements with a chlorine trap were employed to indirectly\nobtain CER’s Faradaic efficiency (FE) by measuring the FE of\nthe competing oxygen evolution reaction. Textural, chemical, and electrochemical\ncharacterization techniques were employed to confirm the identity\nof the developed anodes and depict the electrocatalytic performance.\nThe findings reported herein could offer potential avenues for similar\ncatalytic systems in both conventional CER and emerging electrosynthesis\napproaches utilizing saline waters.