Print Email Facebook Twitter In Situ Study of Hydrogen Permeable Electrodes for Electrolytic Ammonia Synthesis Using Near Ambient Pressure XPS Title In Situ Study of Hydrogen Permeable Electrodes for Electrolytic Ammonia Synthesis Using Near Ambient Pressure XPS Author Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage) Izelaar, B. (TU Delft Large Scale Energy Storage) van Noordenne, D.D. (TU Delft ChemE/Materials for Energy Conversion and Storage) Jungbacker, M.P. (TU Delft ChemE/Materials for Energy Conversion and Storage) Kolen, M. (TU Delft ChemE/Materials for Energy Conversion and Storage) Karanth, P. (TU Delft ChemE/Materials for Energy Conversion and Storage) Cruz, Daniel (Fritz-Haber-Institut der Max-Planck-Gesellschaft) Zeller, Patrick (Fritz-Haber-Institut der Max-Planck-Gesellschaft; Helmholtz-Zentrum Berlin für Materialen und Energie GmbH) Pérez-Dieste, Virginia (ALBA Synchrotron Light Facility) Villar-Garcia, Ignacio J. (ALBA Synchrotron Light Facility) Smith, W.A. (TU Delft ChemE/Materials for Energy Conversion and Storage; University of Colorado) Mulder, F.M. (TU Delft ChemE/Materials for Energy Conversion and Storage) Date 2022 Abstract Hydrogen permeable electrodes can be utilized for electrolytic ammonia synthesis from dinitrogen, water, and renewable electricity under ambient conditions, providing a promising route toward sustainable ammonia. The understanding of the interactions of adsorbing N and permeating H at the catalytic interface is a critical step toward the optimization of this NH3 synthesis process. In this study, we conducted a unique in situ near ambient pressure X-ray photoelectron spectroscopy experiment to investigate the solid-gas interface of a Ni hydrogen permeable electrode under conditions relevant for ammonia synthesis. Here, we show that the formation of a Ni oxide surface layer blocks the chemisorption of gaseous dinitrogen. However, the Ni 2p and O 1s XPS spectra reveal that electrochemically driven permeating atomic hydrogen effectively reduces the Ni surface at ambient temperature, while H2 does not. Nitrogen gas chemisorbs on the generated metallic sites, followed by hydrogenation via permeating H, as adsorbed N and NH3 are found on the Ni surface. Our findings suggest that the first hydrogenation step to NH and the NH3 desorption might be limiting under the operating conditions. The study was then extended to Fe and Ru surfaces. The formation of surface oxide and nitride species on iron blocks the H permeation and prevents the reaction to advance; while on ruthenium, the stronger Ru-N bond might favor the recombination of permeating hydrogen to H2 over the hydrogenation of adsorbed nitrogen. This work provides insightful results to aid the rational design of efficient electrolytic NH3 synthesis processes based on but not limited to hydrogen permeable electrodes. Subject adsorptionammonia synthesishydrogen permeationin situNAP-XPSnitrogen To reference this document use: http://resolver.tudelft.nl/uuid:5243a2d4-b23f-41fa-97b6-cc469c3de809 DOI https://doi.org/10.1021/acscatal.2c03609 ISSN 2155-5435 Source ACS Catalysis, 12 (21), 13781-13791 Part of collection Institutional Repository Document type journal article Rights © 2022 D. Ripepi, B. Izelaar, D.D. van Noordenne, M.P. Jungbacker, M. Kolen, P. Karanth, Daniel Cruz, Patrick Zeller, Virginia Pérez-Dieste, Ignacio J. Villar-Garcia, W.A. Smith, F.M. Mulder Files PDF acscatal.2c03609.pdf 2.42 MB Close viewer /islandora/object/uuid:5243a2d4-b23f-41fa-97b6-cc469c3de809/datastream/OBJ/view