Application of a TEMPO-Polypyrrole Polymer for NO[sub.x]-Mediated Oxygen Electroreduction

• Published in: Catalysts 2022-11, Vol.12 (11)
• Main Authors: Lukyanov, Daniil A, Kalnin, Arseniy Y, Rubicheva, Lyubov G, Potapenkov, Vasiliy V, Bakulina, Olga Y, Levin, Oleg V
• Format: Article
• Language: English
• Subjects: Batteries; Fuel cells; Polymer industry; Polymers
• ISSN: 2073-4344; 2073-4344
• DOI: 10.3390/catal12111466

The oxygen reduction reaction (ORR) is one of the key processes for electrochemical energy storage, such as the cathode process in fuel cells and metal-air batteries. To date, the efficiency of the ORR half-reaction limits the overall performance of these energy storage devices. Traditional platinum-based materials are expensive and cannot provide the desired ORR efficiency. As an alternative, a new catalytic scheme for an ORR was proposed, which consisted of an electrode modified with a TEMPO-containing conductive polymer and a solution redox mediator system based on nitrogen oxides (NO[sub.x]). NO[sub.x] is perfect for oxygen reduction in solution, which, however, cannot be efficiently reduced onto a pristine electrode, while TEMPO is inactive in the ORR itself but catalyzes the electrochemical reduction of NO[sub.2] on the electrode surface. Together, these catalysts have a synergistic effect, enabling an efficient ORR in an acidic medium. In the present study, the synthesis of a novel TEMPO-containing conductive polymer and its application in the synergistic ORR system with a NO[sub.x] mediator is described. The proposed mediator system may increase the performance of proton-exchange fuel cells and metal-air batteries.