Electro‐Reconstructed Transition Metal Electrodes for Coupled‐Upgrading of Nitrate Pollution and Waste Poly(Ethylene Terephthalate) Plastics

Abstract Two unrelated forms of pollution, nitrate‐containing wastewater and waste poly(ethylene terephthalate) (PET) plastics, can be converted into high‐value chemicals by electrochemical reduction and oxidation reactions. Herein, coupled electrocatalysis is used for the co‐production of ammonia (NH 3 ) and formic acid (FA) with a cathode formed by reconstructing Co on copper foam (R‐Co/CF) as catalyst for nitrate reduction reaction (NO 3 RR) and with an anode formed by reconstructing NiCo on nickel foam (R‐NiCo/NF) as catalyst for ethylene glycol oxidation reaction (EGOR). The Faraday efficiency of the R‐Co/CF cathode is 96.2% and that of R‐NiCo/NF catalysts is 98.2%. By coupling NO 3 RR and PET hydrolysate oxidation reaction, the cell voltage required at a current density of 50 mA cm −2 is 202 mV lower than that of the traditional NO 3 RR electrolytic system, indicating that electrocatalytic upcycling of PET plastics coupled with NO 3 RR is an energy‐saving and cost‐effective strategy for producing value‐added chemicals. Techno‐economic analysis indicates that compared with a NO 3 RR//OER system, the NO 3 RR//PET hydrolysate oxidation system can save 2.8 × 10 3 kW h −1 in electricity and generate ≈6 900 USD in revenue per tonne of NH 3 .