____________________Dataset of "Impact of Carbon Corrosion and Denitrogenation on the Deactivation of Fe-N-C Catalysts in Alkaline Media"____________________ Last updated: 2024-06-25 ______Contact______ * Ivan Khalakhan * ORCID: 0000-0003-2929-4148 * Department of Surface and Plasma Science, Faculty of Mathematics and Physics Charles University * V Holešovičkách 2, 180 00 Prague 8, Czech Republic ______Principal Investigator______ * Karel Bouzek * ORCID: 0000-0002-0394-0634 * Dept. of Inorganic Technology, Faculty of Chemical Technology, University of chemistry and Technology, Prague * Technicka 5, 166 28, Prague 6, Czech Republic ______Data manager or custodian______ * Šárka Paušová * ORCID: 0000-0003-2494-1510 * Dept. of Inorganic Technology, Faculty of Chemical Technology, University of chemistry and Technology, Prague * Technicka 5, 166 28, Prague 6, Czech Republic ______Licence______ *Dataset for "Impact of Carbon Corrosion and Denitrogenation on the Deactivation of Fe-N-C Catalysts in Alkaline Media" © 2024 by Ivan Khalakhan is licensed under CC BY *licence information: https://creativecommons.org/licenses/by-nc-sa/4.0/?ref=chooser-v1 ------------------------------------------------------------------------------------------------ ______About the dataset______ Fe–N–C catalysts are considered an earth-abundant alternative to Pt in cathodes of anion exchange membrane fuel cells, although their stability still requires improvement for further commercialization. The degradation of Fe–N–C during both load cycles and start–stop events must be understood and mitigated to minimize system costs. Several approaches have recently been proposed to improve the durability of Fe active species during the oxygen reduction reaction in acidic media. On the other hand, knowledge of the degradation of Fe–N–C catalysts during start–stop events of anion exchange membrane fuel cells remains scarce. In this work, we use a gas diffusion electrode half-cell coupled with inductively coupled plasma mass spectrometry (GDE-ICP-MS) to quantify the Fe dissolution rates in the potential range between 0.93 and 1.5 VRHE. It is shown that Fe dissolution accelerates with increased anodic potential and temperature, while it is independent of the presence/absence of O2. The onset potential of Fe dissolution at room temperature agrees with the reported onset potentials of carbon corrosion and denitrogenation, C and N being oxidized to gaseous COx and NOx species, respectively. This correlation supports that the electrochemical oxidation of the N–C matrix triggers the observed catalyst demetalation in these conditions. Using a set of ex situ physicochemical characterization techniques, including spectroscopy and microscopy, the various degrees of degradation under three sets of experimental conditions of interest (O2-RT, O2-HT, and Ar-HT, where RT = 22 °C and HT = 62 °C) are rationalized. Combining the GDE-ICP-MS technique and post-mortem analyses, this work provides detailed insights into the degradation pathways of various Fe, N, and C species during start–stop events, which may inspire the next generation of durable Fe–N–C catalysts for anion exchange membrane fuel cells. ______Methods of data collection______ Sample preparation Commercial Fe-N-C catalyst (PMF-D14401, Lot 0222-01B, Pajarito Powder) was deposited on gas diffusion electrode (GDE) with a microporous layer (H23C8, Freudenberg). Fe-N-C/GDE sample were electrochemically treated under O2 and Ar-purged atmospheres at 22℃ (RT) and 62℃ (HT). XPS spectra: Conventional XPS system (SPECS Surface Nano Analysis, GmbH Germany) with ultrahigh vacuum chamber equipped with a monochromated Al Kα X-ray source (hν = 1486.6 eV) and a multichannel electron energy analyzer (SPECS Phoibos 150) with 1D-DLD detector. ______Methods of data processing______ The dataset contains only raw data, therefore no processing is described. ------------------------------------------------------------------------------------------------ ______File formats______ XPS spectra - original files exported to CSV ______Abbreviations______ XPS X-ray photoelectron spectroscopy BE Binding energy RT Room temperature HT High temperature GDE Gas diffusion electrode ______Units______ All XPS spectra are in binding energy (eV) vs. intensity (cps) ------------------------------------------------------------------------------------------------ ______List of files______ XPS spectra of samples: VZ2_004_021_UK_D_0001_v1.csv XPS spectra of sample Fe-N-C_pristine VZ2_004_021_UK_D_0002_v1.csv XPS spectra of sample Fe-N-C_O2RT VZ2_004_021_UK_D_0003_v1.csv XPS spectra of sample Fe-N-C_O2HT VZ2_004_021_UK_D_0004_v1.csv XPS spectra of sample Fe-N-C_ArHT Anotation of the samples VZ2_004_021_UK_D_0005_v1.pdf Protocol of the electrochemical treatment VZ2_004_021_UK_D_0006_v1.pdf The files from VZ2_004_021_UK_D_0007_v1.tif to VZ2_004_021_UK_D_0036_v1.tif contain all the figures and tables present in the manuscript. The data obtained using Mössbauer spectroscopy, Raman spectroscopy, Scanning transmission electron microscopy, inductively coupled plasma mass spectrometry and GDE half-cell coupled to inductively coupled plasma mass spectrometry are available on request. VZ2_004_021_UK_D_0037_v2.tiff Figure S3 VZ2_004_021_UK_D_0038_v2.tiff Figure S7 The original data are available on request.