Electrochemical dissolution of iridium and iridium oxide particles in acidic mediaJovanovič, Primož (Avtor)
Hodnik, Nejc (Avtor)
Ruiz-Zepeda, Francisco (Avtor)
Arčon, Iztok (Avtor)
Jozinović, Barbara (Avtor)
Zorko, Milena (Avtor)
Bele, Marjan (Avtor)
Šala, Martin (Avtor)
Šelih, Vid Simon (Avtor)
Hočevar, Samo B. (Avtor)
Gaberšček, Miran (Avtor)
Iridium Oxide Par-ticlesElectrochemical Dissolution of IridiumIr L3-edge XANESIridium based particles as the most promising proton exchange membrane electrolyser electrocatalysts were investigated
by transmission electron microscopy (TEM), and by coupling of electrochemical flow cell (EFC) with online inductively
coupled plasma mass spectrometer (ICP-MS). Additionally, a thin-film rotating disc electrode (RDE), an identical location transmission
and scanning electron microscopy (IL-TEM and IL-SEM) as well as an X-ray absorption spectroscopy (XAS) studies have
been performed. Extremely sensitive online time-and potential-resolved electrochemical dissolution profiles revealed that iridium
particles dissolved already well below oxygen evolution reaction (OER) potentials, presumably induced by iridium surface oxidation
and reduction processes, also referred to as transient dissolution. Overall, thermally prepared rutile type IrO2 particles (T-IrO2)
are substantially more stable and less active in comparison to as prepared metallic (A-Ir) and electrochemically pretreated (E-Ir)
analogues. Interestingly, under OER relevant conditions E-Ir particles exhibit superior stability and activity owing to the altered
corrosion mechanism where the formation of unstable Ir(>IV) species is hindered. Due to the enhanced and lasting OER performance,
electrochemically pre-oxidized E-Ir particles may be considered as the electrocatalyst of choice for an improved low temperature
electrochemical hydrogen production device, namely a proton exchange membrane electrolyser.20172017-08-23 09:59:28Delo ni kategorizirano3216COBISS_ID: 6203674ISSN pri članku: 0002-7863OceCobissID: 5281029DOI: 10.1021/jacs.7b08071NUK URN: URN:SI:UNG:REP:MF97OCXHsl