“Nano Lab” advanced characterization platform for studying electrocatalytic iridium nanoparticles dispersed on TiO$_x$N$_y$ supports prepared on Ti transmission electron microscopy grids

Bele, Marjan (author), Koderman Podboršek, Gorazd (author), Lončar, Anja (author), Jovanovič, Primož (author), Hrnjić, Armin (author), Marinko, Živa (author), Kovač, Janez (author), Surca, Angelja Kjara (author), Kamšek, Ana Rebeka (author), Dražić, Goran (author), Hodnik, Nejc (author), Suhadolnik, Luka (author)

Aiming at speeding up the discovery and understanding of promising electrocatalysts, a novel experimental platform, i.e., the Nano Lab, is introduced. It is based on state-of-the-art physicochemical characterization and atomic-scale tracking of individual synthesis steps as well as subsequent electrochemical treatments targeting nanostructured composites. This is provided by having the entire experimental setup on a transmission electron microscopy (TEM) grid. Herein, the oxygen evolution reaction nanocomposite electrocatalyst, i.e., iridium nanoparticles dispersed on a high-surface-area TiO$_x$N$_y$ support prepared on the Ti TEM grid, is investigated. By combining electrochemical concepts such as anodic oxidation of TEM grids, floating electrode-based electrochemical characterization, and identical location TEM analysis, relevant information from the entire composite’s cycle, i.e., from the initial synthesis step to electrochemical operation, can be studied. We reveal that Ir nanoparticles as well as the TiO$_x$N$_y$ support undergo dynamic changes during all steps. The most interesting findings made possible by the Nano Lab concept are the formation of Ir single atoms and only a small decrease in the N/O ratio of the TiO$_x$N$_y$−Ir catalyst during the electrochemical treatment. In this way, we show that the precise influence of the nanoscale structure, composition, morphology, and electrocatalyst’s locally resolved surface sites can be deciphered on the atomic level. Furthermore, the Nano Lab’s experimental setup is compatible with ex situ characterization and other analytical methods, such as Raman spectroscopy, X-ray photoelectron spectroscopy, and identical location scanning electron microscopy, hence providing a comprehensive understanding of structural changes and their effects. Overall, an experimental toolbox for the systematic development of supported electrocatalysts is now at hand.

• Language: English
• Keywords: Nano Lab concept, anodic oxidation, IL-TEM, electrocatalysis, oxygen evolution reaction, iridium nanoparticles, catalysts, oxides, radiology, transition metals, transmission electron microscopy
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: Str. 10421–10430
• Numbering: Vol. 6, iss. 12
• PID: 20.500.12556/RUL-148253
• UDC: 544.3/.4
• ISSN on article: 2574-0970
• DOI: 10.1021/acsanm.3c01368
• COBISS.SI-ID: 158882563
• Publication date in RUL: 07.08.2023

Record is a part of a journal

• Title: ACS applied nano materials
• Shortened title: ACS appl. nano mater.
• Publisher: American Chemical Society
• ISSN: 2574-0970
• COBISS.SI-ID: 32649255

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: kataliza, elektrokatalizatorji, nanokompoziti, elektrokemija, iridij