@article{ghosh_braley_ezhov_worster_valdez-moreira_losovyj_jakubikova_pushkar_smith_2022, title={A Spectroscopically Observed Iron Nitrosyl Intermediate in the Reduction of Nitrate by a Surface-Conjugated Electrocatalyst}, volume={9}, ISSN={["1520-5126"]}, DOI={10.1021/jacs.2c03487}, abstractNote={We report an iron-based graphite-conjugated electrocatalyst (GCC-FeDIM) that combines the well-defined nature of homogeneous molecular electrocatalysts with the robustness of a heterogeneous electrode. A suite of spectroscopic methods, supported by the results of DFT calculations, reveals that the electrode surface is functionalized by high spin (S = 5/2) Fe(III) ions in an FeN4Cl2 coordination environment. The chloride ions are hydrolyzed in aqueous solution, with the resulting cyclic voltammogram revealing a Gaussian-shaped wave assigned to 1H+/1e- reduction of surface Fe(III)-OH surface. A catalytic wave is observed in the presence of NO3-, with an onset potential of -1.1 V vs SCE. At pH 6.0, GCC-FeDIM rapidly reduces NO3- to ammonium and nitrite with 88 and 6% Faradaic efficiency, respectively. Mechanistic studies, including in situ X-ray absorption spectroscopy, suggest that electrocatalytic NO3- reduction involves an iron nitrosyl intermediate. The Fe-N bond length (1.65 Å) is similar to that observed in {Fe(NO)}6 complexes, which is supported by the results of DFT calculations.}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Ghosh, Moumita and Braley, Sarah E. and Ezhov, Roman and Worster, Harrison and Valdez-Moreira, Juan A. and Losovyj, Yaroslav and Jakubikova, Elena and Pushkar, Yulia N. and Smith, Jeremy M.}, year={2022}, month={Sep} }