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1.
Designing new renewable nano-structured electrode and membrane materials for direct alkaline ethanol fuel cell
De Chen, Jia Yang, Jørgen Svendby, Qingjun Chen, Gvido Bratina, Egon Pavlica, Ji-Song Huang, Jessie Lue Shingjiang, 2020, končno poročilo o rezultatih raziskav

Najdeno v: ključnih besedah
Povzetek najdenega: ...fuel cell, ethanol oxidation, graphene, oxygen reduction, catalyst, pt-free, electrochemical impedance...
Ključne besede: fuel cell, ethanol oxidation, graphene, oxygen reduction, catalyst, pt-free, electrochemical impedance spectroscopy
Objavljeno: 03.12.2020; Ogledov: 402; Prenosov: 0
.pdf Polno besedilo (5,31 MB)

2.
Photocatalytic Activity of Zirconium- and Manganese- Codoped Titania in Aqueous Media: The Role of the Metal Dopant and its Incorporation Site
Nataša Novak Tušar, Iztok Arčon, O. L. Pliekhov, Urška Lavrenčič Štangar, 2016, izvirni znanstveni članek

Opis: The development of efficient TiO2-based photocatalysts for water treatment is mainly performed by doping with transition metals or by establishing junctions between different phases, metal–semiconductor or semiconductor–semiconductor. We present, for the first time, the synthesis of Zr- and Mn-modified TiO2 by a redesigned sol–gel technique that allows the formation of heterometallic bridges on the TiO2 surface. Cations of the doping metals are located in the pores of mesoporous anatase and attached to the crystalline TiO2 walls. The presence of the Zr enhances the photoactivity of the TiO2 catalyst. However, the introduction of Mn decreases the photocatalytic efficiency in a nonadditive manner. The inhibition effect was assigned to the side reaction between hydroxyl radicals and Mn ions. The fact that Mn effectively scavenges the hydroxyl radicals and, consequently, inhibits the whole oxidation process is direct proof that hydroxyl radicals are the main reactive species in the photocatalytic oxidative processes on TiO2 surfaces in aqueous media and the process of COH generation is the rate-determining step, which was confirmed using a method based on the decolorization of a commercial dye Bezaktiv Blau in a reaction with Fenton’s reagent as a source of hydroxyl radicals.
Najdeno v: ključnih besedah
Povzetek najdenega: ...the hydroxyl radicals and, consequently, inhibits the whole oxidation process is direct proof that hydroxyl radicals are...
Ključne besede: doping, manganese, oxidation, X-ray absorption spectroscopy, zirconium
Objavljeno: 21.07.2016; Ogledov: 2039; Prenosov: 0
.pdf Polno besedilo (577,49 KB)

3.
Atomic-level mechanisms of magnesium oxidation
Dmytro Orlov, Matjaž Valant, Sandra Gardonio, Mattia Fanetti, 2016, objavljeni znanstveni prispevek na konferenci

Opis: Magnesium has been recently becoming an increasingly popular material for various applications. However, excessive chemical reactivity, and oxidation rate in particular, is a major obstruction on the way of Mg to become widely adopted. A significant problem causing the lack of Mg reactivity control is insufficient understanding of mechanisms involved in the oxidation of magnesium surface. Herewith we present the investigation of atomic-level mechanisms of oxidation initiation and propagation in pure Mg. Namely, X-ray photoelectron spectroscopy at synchrotron Elettra was used as a surface sensitive direct method to determine the valence of Mg and O and the valence band states at the early stage of oxide formation over a principal, most densely packed, crystallographic plane (0001) in pure Mg. The mechanisms of oxygen adsorption on magnesium free surface followed by oxidation (i.e. initiation and kinetics of MgO formation) are clarified. Copyright © 2016 by The Minerals, Metals & Materials Society. All rights reserved.
Najdeno v: ključnih besedah
Ključne besede: Magnesium, Oxidation, Synchrotron radiation, X-ray photoelectron spectroscopy
Objavljeno: 25.08.2017; Ogledov: 2157; Prenosov: 0
.pdf Polno besedilo (2,91 MB)

4.
So reduktivne note v vinu hudič ali angel varuh?
Guillaume Antalick, 2018, polemika, diskusijski prispevek, komentar

Najdeno v: ključnih besedah
Povzetek najdenega: ...Wine, reductive aroma, oxidation, good practice, Slovenia...
Ključne besede: Wine, reductive aroma, oxidation, good practice, Slovenia
Objavljeno: 19.09.2018; Ogledov: 1444; Prenosov: 6

5.
Effect of the Morphology of the High-Surface-Area Support on the Performance of the Oxygen-Evolution Reaction for Iridium Nanoparticles
Leonard Moriau, Marjan Bele, Živa Marinko, Francisco Ruiz-Zepeda, Gorazd Koderman, Martin Šala, Angelija Kjara Šurca, Janez Kovač, Iztok Arčon, Primož Jovanovič, Nejc Hodnik, Luka Suhadolnik, 2021, izvirni znanstveni članek

Opis: The development of affordable, low-iridium-loading, scalable, active, and stable catalysts for the oxygen-evolution reaction (OER) is a requirement for the commercialization of proton-exchange membrane water electrolyzers (PEMWEs). However, the synthesis of high-performance OER catalysts with minimal use of the rare and expensive element Ir is very challenging and requires the identification of electrically conductive and stable high-surface-area support materials. We developed a synthesis procedure for the production of large quantities of a nanocomposite powder containing titanium oxynitride (TiONx) and Ir. The catalysts were synthesized with an anodic oxidation process followed by detachment, milling, thermal treatment, and the deposition of Ir nanoparticles. The anodization time was varied to grow three different types of nanotubular structures exhibiting different lengths and wall thicknesses and thus a variety of properties. A comparison of milled samples with different degrees of nanotubular clustering and morphology retention, but with identical chemical compositions and Ir nanoparticle size distributions and dispersions, revealed that the nanotubular support morphology is the determining factor governing the catalyst’s OER activity and stability. Our study is supported by various state-of-the-art materials’ characterization techniques, like X-ray photoelectron spectroscopy, scanning and transmission electron microscopies, Xray powder diffraction and absorption spectroscopy, and electrochemical cyclic voltammetry. Anodic oxidation proved to be a very suitable way to produce high-surface-area powder-type catalysts as the produced material greatly outperformed the IrO2 benchmarks as well as the Ir-supported samples on morphologically different TiONx from previous studies. The highest activity was achieved for the sample prepared with 3 h of anodization, which had the most appropriate morphology for the effective removal of oxygen bubbles.
Najdeno v: ključnih besedah
Povzetek najdenega: ...Ir. The catalysts were synthesized with an anodic oxidation process followed by detachment, milling, thermal treatment, and...
Ključne besede: electrocatalysis, oxygen-evolution reaction, TiONx-Ir powder catalyst, iridium nanoparticles, anodic oxidation, morphology−activity correlation
Objavljeno: 04.01.2021; Ogledov: 319; Prenosov: 0
.pdf Polno besedilo (6,36 MB)

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