Zhang, W.; Zhan, S.; Jie, X.; Petit, T.; Schlesiger, C.; Mellin, M.; Hofmann, J.P.; Heil, T.; Müller, R.; Leopold, K.; Oschatz, M.: Coordinative Stabilization of Single Bismuth Sites in a Carbon-Nitrogen Matrix to Generate Atom-Efficient Catalysts for Electrochemical Nitrate Reduction to Ammonia. Advanced Science 10 (2023), p. 2302623/1-9
10.1002/advs.202302623
Open Access Version
Abstract:
Electrochemical nitrate reduction to ammonia powered by renewableelectricity is not only a promising alternative to the established energy-intenseand non-ecofriendly Haber–Bosch reaction for ammonia generation but also afuture contributor to the ever-more important denitrification schemes.Nevertheless, this reaction is still impeded by the lack of understanding forthe underlying reaction mechanism on the molecular scale which is necessaryfor the rational design of active, selective, and stable electrocatalysts. Herein,a novel single-site bismuth catalyst (Bi-N-C) for nitrate electroreduction isreported to produce ammonia with maximum Faradaic efficiency of 88.7%and at a high rate of 1.38 mg h−1mgcat−1at−0.35 V versus reversiblehydrogen electrode (RHE). The active center (described as BiN2C2)isuncovered by detailed structural analysis. Coupled density functional theorycalculations are applied to analyze the reaction mechanism and potentialrate-limiting steps for nitrate reduction based on the BiN2C2model. Thefindings highlight the importance of model catalysts to utilize the potential ofnitrate reduction as a new-generation nitrogen-management technologybased on the construction of efficient active sites.