1. Efficient Iron Phosphide Catalyst as a Counter Electrode in Dye-Sensitized Solar Cells : articleAbdullah Yildiz, Takwa Chouki, Aycan Atli, Moussab Harb, Sammy W Verbruggen, Rajeshreddy Ninakanti, Saim Emin, 2021, izvirni znanstveni članek Opis: Developing an efficient material as a counter electrode (CE) with excellent catalytic activity, intrinsic stability, and low cost is essential for the commercial application of dye-sensitized solar cells (DSSCs). Transition metal phosphides have been demonstrated as outstanding multifunctional catalysts in a broad range of energy conversion technologies. Here, we exploited different phases of iron phosphide as CEs in DSSCs with an I–/I3–-based electrolyte. Solvothermal synthesis using a triphenylphosphine precursor as a phosphorus source allows to grow a Fe2P phase at 300 °C and a FeP phase at 350 °C. The obtained iron phosphide catalysts were coated on fluorine-doped tin oxide substrates and heat-treated at 450 °C under an inert gas atmosphere. The solar-to-current conversion efficiency of the solar cells assembled with the Fe2P material reached 3.96 ± 0.06%, which is comparable to the device assembled with a platinum (Pt) CE. DFT calculations support the experimental observations and explain the fundamental origin behind the improved performance of Fe2P compared to FeP. These results indicate that the Fe2P catalyst exhibits excellent performance along with desired stability to be deployed as an efficient Pt-free alternative in DSSCs.
Ključne besede: Iron phosphide, catalyst, counter electrode, dye-sensitized solar cell, solvothermal synthesis
Objavljeno v RUNG: 06.02.2023; Ogledov: 267; Prenosov: 0
Gradivo ima več datotek! Več... |
2. Progressive pedagogies for innovation among art, science and technology : the case of mastmodule.euPeter Purg, N. Castillo-Rutz, Sergi Bermúdez i Badia, C. Csíkszentmihályi, Jurij V. Krpan, F. Hedeer, D. L. Sousa, Klemen Širok, 2022, izvirni znanstveni članek Opis: Even if aiming at technical innovation, an interdisciplinary curriculum can and should include social
values. The Master Module in Art, Science and Technology project attempted to do so by developing
the innovation catalyst profile, a graduate who critically reflects on the creation process by combining
art thinking and design thinking. Within a pilot of the MAST module students from three universities
responded to timely challenges such as ‘The Future of Work’ and ‘Solidarity,’ through which the project
staff tested progressive pedagogical solutions like cross-disciplinary mentoring and situated knowledge
sharing. Introducing European social values in both artistic and technical education, the article presents
models, experiments and inspirations discussed against discursive analysis and course evaluation data.
In order to support not only inclusive but also sustainable teaching and learning approaches, novel
methods and tools may become daringly innovative as well as critical of both their pedagogical and
the wider social setting.
Ključne besede: art thinking, curriculum design, social values, innovation catalyst, design thinking
Objavljeno v RUNG: 27.06.2022; Ogledov: 548; Prenosov: 21
 Povezava na celotno besedilo
Gradivo ima več datotek! Več... |
3. Photo-Chemically-Deposited and Industrial Cu/ZnO/Al2O3 Catalyst Material Surface Structures During CO2 Hydrogenation to Methanol: EXAFS, XANES and XPS Analyses of Phases After Oxidation, Reduction, and ReactionMaja Pori, Iztok Arčon, Venkata Dasireddy, Blaž Likozar, 2021, izvirni znanstveni članek Opis: Industrial Cu/ZnO/Al2O3 or novel rate catalysts, prepared with a photochemical deposition method, were studied under functional CH3OH synthesis conditions at the set temperature (T) range of 240–350 °C, 20 bar pressure, and stoichiometric carbon dioxide/hydrogen composition. Analytical scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray adsorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) methods were systematically utilized to investigate the interfaces, measured local geometry, and chemical state electronics around the structured active sites of commercially available Cu/ZnO/Al2O3 material or synthesized Cu/ZnO. Processed Cu K-edge EXAFS analysis suggested that various Cu atom species, clusters, metallic fcc Cu, Cu oxides (Cu2O or CuO) and the Cu0.7Zn2 alloy with hexagonal crystalline particles are contained after testing. It was proposed that in addition to the model’s Cu surface area, the amount, ratio and dispersion of the mentioned bonded Cu compounds significantly influenced activity. Additionally, XPS revealed that carbon may be deposited on the commercial Cu/ZnO/Al2O3, forming the inactive carbide coating with Cu or/and Zn, which may be the cause of basicity’s severe deactivation during reactions. The selectivity to methanol decreased with increasing T, whereas more Cu0.7Zn2 inhibited the CO formation through reverse water–gas shift (RWGS) CO2 reduction.
Ključne besede: CH3OH synthesis, Cu/ZnO-based catalyst, XPS, XANES, EXAFS analyses, Catalyst selectivity and activity
Objavljeno v RUNG: 03.06.2021; Ogledov: 1461; Prenosov: 0
Gradivo ima več datotek! Več... |
4. Effect of the Morphology of the High-Surface-Area Support on the Performance of the Oxygen-Evolution Reaction for Iridium NanoparticlesLeonard 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.
Ključne besede: electrocatalysis, oxygen-evolution reaction, TiONx-Ir powder catalyst, iridium nanoparticles, anodic oxidation, morphology−activity correlation
Objavljeno v RUNG: 04.01.2021; Ogledov: 1819; Prenosov: 0
Gradivo ima več datotek! Več... |
5. Designing new renewable nano-structured electrode and membrane materials for direct alkaline ethanol fuel cell : Information on catalytic activity, structure and electric current con- ductivity of new catalysts on supporting substratesEgon Pavlica, Gvido Bratina, Jørgen Svendby, Qingjun Chen, Jia Yang, De Chen, Ji-Song Huang, Jessie Lue Shingjiang, 2020, končno poročilo o rezultatih raziskav Ključne besede: fuel cell, ethanol oxidation, graphene, oxygen reduction, catalyst, pt-free, electrochemical impedance spectroscopy
Objavljeno v RUNG: 03.12.2020; Ogledov: 2064; Prenosov: 0
Gradivo ima več datotek! Več... |
6. |
7. A Biogenerated Polymetallic Catalyst from Society's WastesOreste Piccolo, Stefano Paganelli, Petro Zanatta, Sebastiano Tieuli, Laura Sperni, Franco Baldi, Iztok Arčon, Michele Gallo, Katarina Vogel-Mikuš, 2019, izvirni znanstveni članek Opis: Aims:Preparation of the new metals - polymeric composite, Met x-EPS (I), to be used as a green catalyst in water or in two-phase aqueous conditions.
Study Design:
Recovery and valorization of polymetallic
wastes to obtain directly new catalysts
using a microorganism to explore their application in removal of difficult and dangerous chemical
pollutants present in aqueous environment
Ključne besede: Metals
-
polymeric composite, biogenerated polymetallic exopolysaccharide, new catalyst
from metallic wastes, hydrodechlorination
of PCBs in water
Objavljeno v RUNG: 06.05.2019; Ogledov: 2709; Prenosov: 0
Gradivo ima več datotek! Več... |
8. Alternative Recovery and Valorization of Metals from Exhausted Catalytic Converters in a New Smart Polymetallic CatalystSebastiano Tieuli, Franco Baldi, Iztok Arčon, Katarina Vogel-Mikuš, Michele Gallo, Laura Sperni, Oreste Piccolo, Stefano Paganelli, 2019, izvirni znanstveni članek Opis: A new metals-polymeric composite, Metx-EPS (I), was prepared
to be used as catalyst in water or in two-phase aqueous
conditions. The metals source was an exhausted catalytic
converter that was grinded and treated with an acidic solution at room temperature. After filtration, the solution was concentrated, neutralized and added to a broth of Klebsiella oxytoca DSM 29614 to produce (I) where metals are embedded in a peculiar polysaccharide structure (EPS). The composite was easily recovered from the fermentation broth and purified. The process protocol was verified many times and was shown to be reproducible satisfactorily. The % recovery of metals, originally present in the converter, was good as determined by atomic
absorption. The morphology and the chemical state of main
metals in (I) were investigated by X-ray absorption spectroscopy
methods (XANES and EXAFS). No metallic alloy seems to
be evident. The catalytic activity and a possible synergic effect due to the presence of the different metals was valuated in the hydrogenation of some substrates, valuable precursors for theproduction of fine chemicals.
Ključne besede: Biogenerated polymetallic exopolysaccharide, biphasic catalysis, hydrogenation, metals-polymeric
composite, new catalyst from metallic wastes, EXAFS, XANES
Objavljeno v RUNG: 06.05.2019; Ogledov: 2505; Prenosov: 0
Gradivo ima več datotek! Več... |
9. In-situ XAS analysis of nanoshaped CuO/CeO2 catalysts used for N2O decompositionIztok Arčon, Maxim Zabilsky, Petar Djinović, Albin Pintar, 2018, objavljeni povzetek znanstvenega prispevka na konferenci Opis: The goal of this research is to establish the working state and correlations between atomic structure and catalytic activity of nanoshaped CuO/CeO2 catalysts used in N2O decomposition reaction. The catalysts contained CuO nanoclusters dispersed over different CeO2 morphologies: nano-rods and nano-cubes. N2O is a side product of nitric and adipic acid production and a very potent greenhouse gas that is formed in amounts estimated at about 400 Mt/a of CO2 equivalent. Consequently, the development of robust, active and selective catalysts for N2O decomposition is of a great environmental and economical interest. CeO2-based materials promoted by CuO represent a new class of catalysts that exhibit considerable activity in N2O decomposition reaction between 300 and 500 °C [1-3], and are significantly cheaper and more efficient than Pt, Pd or Rh based catalysts.
In order to maximize the efficiency of the catalyst, the active site in this reaction needs to be identified and the mechanism clarified. In-situ Cu K-edge and Ce L3-edge XANES and EXAFS analysis was done on a set of CuO/CeO2 catalysts with different ceria morphology (nano-cubes, nano-rods) and Cu loadings between 2 to 8 wt. %, during N2O decomposition reaction, under controlled reaction conditions at 400 °C. The XAS spectra were measured in-situ, in a tubular reactor, filled with protective He atmosphere at 1 bar, first at RT, then during heating, and at final temperature of 400 °C, during catalytic reaction, when the catalyst was exposed to a small amount (0.2 vol%) of N2O mixed with He.
The Cu K-edge and Ce L3-edge XANES and EXAFS analysis reveals changes in valence and local structure of Cu and Ce in the CuO/CeO2 catalysts. In the initial state (in He at RT), copper is present in the form of CuO nanoparticles attached to the CeO2 surface. After heating in He to 400 °C, partial (10%) reduction of Ce [Ce(IV)→Ce(III)] is detected, significant part of Cu(II) is reduced to Cu(I) and Cu(0) species, and direct Cu-Cu bonds are formed. During catalytic N2O decomposition at 400°C, all Ce(III) is oxidized back to Ce(VI), and a major part of Cu is oxidized back to Cu(II), with about 5% of Cu(I) remaining in equilibrium state. Observed structural and valence changes of copper strongly depend on its loading and CeO2 morphology.
With systematic In-situ XAS analysis of different nanoshaped CuO/CeO2 catalysts, we identified the structural characteristics and changes of Cu and Ce phases during catalytic N2O decomposition reaction, which could lead to identification of the active catalytic site during the reaction and further improve the performance of these promising catalytic materials.
Ključne besede: EXAFS, CuO/CeO2 catalyst, N2O decomposition
Objavljeno v RUNG: 12.09.2018; Ogledov: 3010; Prenosov: 0
Gradivo ima več datotek! Več... |
10. |
