Autor segons l'article: Tzaguy A; Masip-Sánchez A; Avram L; Solé-Daura A; López X; Poblet JM; Neumann R
Departament: Química Física i Inorgànica
Autor/s de la URV: López Fernández, Javier / Poblet Rius, Josep Maria / Solé Daura, Albert
Resum: The electrification of ammonia synthesis is a key target for its decentralization and lowering impact on atmospheric CO2 concentrations. The lithium metal electrochemical reduction of nitrogen to ammonia using alcohols as proton/electron donors is an important advance, but requires rather negative potentials, and anhydrous conditions. Organometallic electrocatalysts using redox mediators have also been reported. Water as a proton and electron donor has not been demonstrated in these reactions. Here a N2 to NH3 electrocatalytic reduction using an inorganic molecular catalyst, a tri-iron substituted polyoxotungstate, {SiFe3W9}, is presented. The catalyst requires the presence of Li+ or Na+ cations as promoters through their binding to {SiFe3W9}. Experimental NMR, CV and UV-vis measurements, and MD simulations and DFT calculations show that the alkali metal cation enables the decrease of the redox potential of {SiFe3W9} allowing the activation of N2. Controlled potential electrolysis with highly purified 14N2 and 15N2 ruled out formation of NH3 from contaminants. Importantly, using Na+ cations and polyethylene glycol as solvent, the anodic oxidation of water can be used as a proton and electron donor for the formation of NH3. In an undivided cell electrolyzer under 1 bar N2, rates of NH3 formation of 1.15 nmol sec-1 cm-2, faradaic efficiencies of ∼25%, 5.1 equiv of NH3 per equivalent of {SiFe3W9} in 10 h, and a TOF of 64 s-1 were obtained. The future development of suitable high surface area cathodes and well solubilized N2 and the use of H2O as the reducing agent are important keys to the future deployment of an electrocatalytic ammonia synthesis.
Àrees temàtiques: Química Materiais Interdisciplinar General chemistry Farmacia Engenharias iv Engenharias iii Engenharias ii Colloid and surface chemistry Ciências biológicas ii Ciências biológicas i Ciências agrárias i Ciência de alimentos Chemistry, multidisciplinary Chemistry (miscellaneous) Chemistry (all) Chemistry Catalysis Biochemistry Astronomia / física
Accès a la llicència d'ús: https://creativecommons.org/licenses/by/3.0/es/
Adreça de correu electrònic de l'autor: javier.lopez@urv.cat josepmaria.poblet@urv.cat
Identificador de l'autor: 0000-0003-0322-6796 0000-0002-4533-0623
Data d'alta del registre: 2024-01-27
Versió de l'article dipositat: info:eu-repo/semantics/publishedVersion
Enllaç font original: https://pubs.acs.org/doi/full/10.1021/jacs.3c06167
URL Document de llicència: http://repositori.urv.cat/ca/proteccio-de-dades/
Referència a l'article segons font original: Journal Of The American Chemical Society. 145 (36): 19912-19924
Referència de l'ítem segons les normes APA: Tzaguy A; Masip-Sánchez A; Avram L; Solé-Daura A; López X; Poblet JM; Neumann R (2023). Electrocatalytic Reduction of Dinitrogen to Ammonia with Water as Proton and Electron Donor Catalyzed by a Combination of a Tri-ironoxotungstate and an Alkali Metal Cation. Journal Of The American Chemical Society, 145(36), 19912-19924. DOI: 10.1021/jacs.3c06167
DOI de l'article: 10.1021/jacs.3c06167
Entitat: Universitat Rovira i Virgili
Any de publicació de la revista: 2023
Tipus de publicació: Journal Publications
Repositori URV