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24. Ni-MoO 2 Composite Coatings Electrodeposited at Porous Ni Substrate as Efficient Alkaline Water Splitting Cathodes.

Author

Petričević, Aleksandar, Gojgić, Jelena, Bernäcker, Christian I., Rauscher, Thomas, Bele, Marjan, Smiljanić, Milutin, Hodnik, Nejc, Elezović, Nevenka, Jović, Vladimir D., and Krstajić Pajić, Mila N.

Subjects
HYDROGEN evolution reactions, ELECTRODE performance, COMPOSITE coating, SUBSTRATES (Materials science), WATER electrolysis
Abstract

To obtain highly efficient yet easily produced water-splitting cathodes, Ni-MoO2 composite coatings were electrodeposited at a Ni foam substrate with an open-pore structure, pore size of 450 µm, in a Watts-type bath. The concentration of MoO2 particles (about 100 nm) was varied, while the intensive mixing of the solution was provided by air bubbling with 0.5 L min−1. Electrodeposition was performed at different constant current densities at room temperature. The morphology and composition of the coatings were investigated by SEM and EDS. The hydrogen evolution reaction (HER) was tested in KOH of different concentrations, at several temperatures, in a three-electrode H-cell by recording polarization curves and EIS measurements. The lowest achieved HER overpotential was −158 mV at −0.5 A cm−2. Up-scaled samples, 3 × 3.3 cm2, were tested in a single zero-gap cell showing decreasing cell voltage (from 2.18 V to 2.11 V) at 0.5 A cm−2 over 5 h in 30% KOH at 70 °C with electrolyte flow rate of 58 mL min−1. Compared to pure Ni foams used as both cathode and anode under the same conditions, the cell voltage is decreased by 200 mV, showing improved electrode performance. [ABSTRACT FROM AUTHOR]

Published
2024
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26. Metal–Support Interaction between Titanium Oxynitride and Pt Nanoparticles Enables Efficient Low-Pt-Loaded High-Performance Electrodes at Relevant Oxygen Reduction Reaction Current Densities

Author

Hrnjić, Armin, primary, Kamšek, Ana Rebeka, additional, Bijelić, Lazar, additional, Logar, Anja, additional, Maselj, Nik, additional, Smiljanić, Milutin, additional, Trputec, Jan, additional, Vovk, Natan, additional, Pavko, Luka, additional, Ruiz-Zepeda, Francisco, additional, Bele, Marjan, additional, Jovanovič, Primož, additional, and Hodnik, Nejc, additional

Published
2024
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27. Optimization of RuIr-Based Nanocatalyst for Superior Hydrogen Evolution Reaction Performance

Author

Popović, Aleksandra, Marić, Ivan, Bele, Marjan, Pavko, Luka, Ruiz-Zepeda, Francisco, Bijelić, Lazar, Grgur, Branimir, Smiljanić, Millutin, Hodnik, Nejc, Popović, Aleksandra, Marić, Ivan, Bele, Marjan, Pavko, Luka, Ruiz-Zepeda, Francisco, Bijelić, Lazar, Grgur, Branimir, Smiljanić, Millutin, and Hodnik, Nejc

Abstract

The production of green hydrogen through water electrolysis driven by renewable energy, is essential for sustainable energy solutions. However, its implementation is hindered by significant energy demands and costs, primarily due to the high overpotential of key electrochemical processes, such as hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). This research introduces an innovative HER electrocatalyst composed of RuIr nanoparticles supported on nitrogen-doped titanium oxide within reduced graphene oxide (RuIr/TiON-C). Structural characterization of the catalyst was carried out using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The electrochemical performance and durability of RuIr/TiON-C were evaluated in both alkaline and acidic media, demonstrating superior HER activity compared to RuIr/C, Ru/C, Ir/C, and Pt/C benchmarks. In alkaline conditions, RuIr/TiON-C surpassed all other tested materials, while in acidic conditions, it performed comparably to Pt/C, the leading catalyst. Stability tests, including electrochemical and identical location TEM (IL-TEM) analyses, confirmed the robust operation of RuIr/TiON-C. The exceptional HER activity and durability are attributed to the existence of bimetallic Ru-Ir active sites and the strong metal-support interaction (SMSI) between the support and these active sites. These factors optimize hydrogen-free adsorption energy and reduce the water dissociation barrier, ensuring efficient and HER [1].

Published
2024

28. Ni-MoO2 Composite Coatings Electrodeposited at Porous Ni Substrate as Efficient Alkaline Water Splitting Cathodes

Author

Petričević, Aleksandar, Gojgić, Jelena, Bernäcker, Christian I., Rauscher, Thomas, Bele, Marjan, Smiljanić, Milutin, Hodnik, Nejc, Elezović, Nevenka, Jović, Vladimir D., Krstajić Pajić, Mila N., Petričević, Aleksandar, Gojgić, Jelena, Bernäcker, Christian I., Rauscher, Thomas, Bele, Marjan, Smiljanić, Milutin, Hodnik, Nejc, Elezović, Nevenka, Jović, Vladimir D., and Krstajić Pajić, Mila N.

Abstract

To obtain highly efficient yet easily produced water-splitting cathodes, Ni-MoO2 composite coatings were electrodeposited at a Ni foam substrate with an open-pore structure, pore size of 450 µm, in a Watts-type bath. The concentration of MoO2 particles (about 100 nm) was varied, while the intensive mixing of the solution was provided by air bubbling with 0.5 L min−1. Electrodeposition was performed at different constant current densities at room temperature. The morphology and composition of the coatings were investigated by SEM and EDS. The hydrogen evolution reaction (HER) was tested in KOH of different concentrations, at several temperatures, in a three-electrode H-cell by recording polarization curves and EIS measurements. The lowest achieved HER overpotential was −158 mV at −0.5 A cm−2. Up-scaled samples, 3 × 3.3 cm2, were tested in a single zero-gap cell showing decreasing cell voltage (from 2.18 V to 2.11 V) at 0.5 A cm−2 over 5 h in 30% KOH at 70 °C with electrolyte flow rate of 58 mL min−1. Compared to pure Ni foams used as both cathode and anode under the same conditions, the cell voltage is decreased by 200 mV, showing improved electrode performance.

Published
2024

29. Fine-Tuning Bimetallic Nanostructures for Enhanced Hydrogen Evolution Reaction

Author

Popović, Aleksandra, Marić, Ivan, Bele, Marjan, Pavko, Luka, Ruize-Zepeda, Francisco, Bijelić, Lazar, Grgur, Branimir, Smiljanić, Millutin, Hodnik, Nejc, Popović, Aleksandra, Marić, Ivan, Bele, Marjan, Pavko, Luka, Ruize-Zepeda, Francisco, Bijelić, Lazar, Grgur, Branimir, Smiljanić, Millutin, and Hodnik, Nejc

Abstract

Water electrolysis, powered by electricity obtained from renewable sources, emerges as a pivotal method for green hydrogen production, a crucial energy vector. However, its widespread adoption faces challenges due to high energy consumption and resultant high costs attributed to the substantial overpotential of electrochemical reactions, specifically cathodic hydrogen evolution (HER) and anodic oxygen evolution (OER) reactions [1]. In this study, we introduce a novel electrocatalyst for HER, comprising RuIr nanoparticles supported on nitrogen-doped titanium oxide integrated into reduced graphene oxide (RuIr/TiON-C). The electrochemical activity and stability of RuIr/TiON-C are thoroughly examined in both alkaline and acidic environments and compared to RuIr/C analog as well as Ru/C, Ir/C, and Pt/C benchmarks. In alkaline electrolyte, RuIr/TiON-C outperforms all other tested materials whereas in acidic media it performs similarly to Pt/C, the current leading catalyst for HER in acid. Furthermore, RuIr/TiON-C demonstrate robust HER performance during potentiodynamic and potentiostatic degradation tests. The enhanced HER activity and stability of the investigated material can be linked to two effects: alloying of Ru and Ir and strong metal metal-support interaction (SMSI) triggered between the TiONx support and RuIr nanoparticles. The synergy of these two factors results in increased catalytic activity for the hydrogen evolution reaction.

Published
2024

35. “Nano Lab” Advanced Characterization Platform for Studying Electrocatalytic Iridium Nanoparticles Dispersed on TiOxNy Supports Prepared on Ti Transmission Electron Microscopy Grids

Author

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

Published
2023
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36. Mechanistic Study of Fast Performance Decay of PtCu Alloy-based Catalyst Layers for Polymer Electrolyte Fuel Cells through Electrochemical Impedance Spectroscopy

Author

Grandi, Maximilian, primary, Gatalo, Matija, additional, Kamšek, Ana Rebeka, additional, Kapun, Gregor, additional, Mayer, Kurt, additional, Ruiz-Zepeda, Francisco, additional, Šala, Martin, additional, Marius, Bernhard, additional, Bele, Marjan, additional, Hodnik, Nejc, additional, Bodner, Merit, additional, Gaberšček, Miran, additional, and Hacker, Viktor, additional

Published
2023
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39. Nanotubular TiOxNy-Supported Ir Single Atoms and Clusters as Thin-Film Electrocatalysts for Oxygen Evolution in Acid Media

Author

Suhadolnik, Luka, primary, Bele, Marjan, additional, Čekada, Miha, additional, Jovanovič, Primož, additional, Maselj, Nik, additional, Lončar, Anja, additional, Dražić, Goran, additional, Šala, Martin, additional, Hodnik, Nejc, additional, Kovač, Janez, additional, Montini, Tiziano, additional, Melchionna, Michele, additional, and Fornasiero, Paolo, additional

Published
2023
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43. Improving the HER activity and stability of Pt nanoparticles by titanium oxynitride support

Author

Smiljanić, Milutin, Panić, Stefan, Bele, Marjan, Ruiz-Zepeda, Francisco, Pavko, Luka, Gašparič, Lea, Kokalj, Anton, Gaberšček, Miran, and Hodnik, Nejc

Subjects
strong metal−support interaction, platina, nanodelci, vodik, General Chemistry, evolution reactions, elektrokemija, elektroliza, titanium oxynitride, DFT, Catalysis, catalysts, hydrogen evolution reaction, strong metal-support interaction, udc:544.5/.6, XPS, nanoparticles, platinum, metal nanoparticles, platinum nanoparticles
Abstract

Water electrolysis powered by renewables is regarded as the feasible route for the production of hydrogen, obtained at the cathode side through electrochemical hydrogen evolution reaction (HER). Herein, we present a rational strategy to improve the overall HER catalytic performance of Pt, which is known as the best monometallic catalyst for this reaction, by supporting it on a conductive titanium oxynitride (TiON$_x$) dispersed over reduced graphene oxide nanoribbons. Characterization of the Pt/TiON$_x$ composite revealed the presence of small Pt particles with diameters between 2 and 3 nm, which are well dispersed over the TiON$_x$ support. The Pt/TiON$_x$ nanocomposite exhibited improved HER activity and stability with respect to the Pt/C benchmark in an acid electrolyte, which was ascribed to the strong metal−support interaction (SMSI) triggered between the TiON$_x$ support and grafted Pt nanoparticles. SMSI between TiON$_x$ and Pt was evidenced by X-ray photoelectron spectroscopy (XPS) through a shift of the binding energies of the characteristic Pt 4f photoelectron lines with respect to Pt/C. Density functional theory (DFT) calculations confirmed the strong interaction between Pt nanoparticles and the TiON$_x$ support. This strong interaction improves the stability of Pt nanoparticles and weakens the binding of chemisorbed H atoms thereon. Both of these effects may result in enhanced HER activity.

Published
2023

47. Alternative and facile production pathway towards obtaining high surface area PtCo/C intermetallic catalysts for improved PEM fuel cell performance

Author

Heizmann, Philipp A., primary, Nguyen, Hien, additional, von Holst, Miriam, additional, Fischbach, Andreas, additional, Kostelec, Mitja, additional, Gonzalez Lopez, Francisco Javier, additional, Bele, Marjan, additional, Pavko, Luka, additional, Đukić, Tina, additional, Šala, Martin, additional, Ruiz-Zepeda, Francisco, additional, Klose, Carolin, additional, Gatalo, Matija, additional, Hodnik, Nejc, additional, Vierrath, Severin, additional, and Breitwieser, Matthias, additional

Published
2023
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48. Electrochemically-grown chloride-free Cu [sub] 2O nanocubes favorably electroreduce CO [sub] 2 to methane

Author

Popovic, Stefan, Nazrulla, Mohammed Azeezulla, Šket, Primož, Mohaideen, Kamal Khaja, Likozar, Blaž, Suhadolnik, Luka, Pavko, Luka, Surca, Angelja Kjara, Bele, Marjan, and Hodnik, Nejc

Subjects
elektrokemija, ogljikov dioksid, reakcije, redukcija, udc:544.5/.6
Abstract

Nasl. z nasl. zaslona. Opis vira z dne 28. 12. 2022. Št. članka: 141458. Bibliografija: str. 8-9. Abstract.

Published
2022

49. Iridium Stabilizes Ceramic Titanium Oxynitride Support for Oxygen Evolution Reaction

Author

Koderman Podboršek, Gorazd, primary, Suhadolnik, Luka, additional, Lončar, Anja, additional, Bele, Marjan, additional, Hrnjić, Armin, additional, Marinko, Živa, additional, Kovač, Janez, additional, Kokalj, Anton, additional, Gašparič, Lea, additional, Surca, Angelja Kjara, additional, Kamšek, Ana Rebeka, additional, Dražić, Goran, additional, Gaberšček, Miran, additional, Hodnik, Nejc, additional, and Jovanovič, Primož, additional

Published
2022
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