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11. Strain‐Engineered Ir Shell Enhances Activity and Stability of Ir‐Ru Catalysts for Water Electrolysis: An Operando Wide‐Angle X‐Ray Scattering Study.

Author

Hrbek, Tomáš, Kúš, Peter, Drnec, Jakub, Mirolo, Marta, Nedumkulam, Hridya, Martens, Isaac, Nováková, Jaroslava, Skála, Tomáš, and Matolínová, Iva

Subjects
*OXYGEN evolution reactions, *CATALYTIC activity, *SURFACE potential, *OXIDATION states, *CATALYSTS
Abstract

Ir‐Ru alloys with high Ru content serve as stable and highly active catalysts for the Oxygen Evolution Reaction (OER) in Proton Exchange Membrane Water Electrolyzers (PEM‐WEs), enabling efficient operation with low Ir loadings (150 µg cm−2). Despite this, the mechanisms behind their enhanced stability remain unclear. In this study, operando Wide‐Angle X‐ray Scattering (WAXS) and ex situ techniques are utilized to investigate the structural evolution of these magnetron‐sputtered alloys during a PEM‐WE operation. The findings reveal that Ru leaches from the surface upon potential application, forming a dynamic Ir‐Ru@IrOx core‐shell structure. The Ir shell, strained by the Ir‐Ru core, maintains a lower oxidation state than pure Ir catalyst, leading to superior catalytic activity and stability. Remarkably, the Ir‐Ru 25:75 catalyst demonstrates better stability over Ir‐Ru 50:50, despite its higher Ru content, due to the better protection of the subsurface Ir and Ru from oxidation and dissolution. This study not only clarifies the performance‐enhancing mechanisms of Ir‐Ru catalysts but also suggests that other, more economical materials, such as Co or Ti, could serve as effective cores in Ir‐M systems, offering a pathway to more cost‐effective catalysts for PEM‐WE applications. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Genetic Diversity of New World Crocodilians

Author

Amavet, Patricia Susana, Zucoloto, Rodrigo Barban, Hrbek, Tomas, Farias, Izeni Pires, Zucoloto, Rodrigo Barban, editor, Amavet, Patricia Susana, editor, Verdade, Luciano Martins, editor, and Farias, Izeni Pires, editor

Published
2021
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20. Temperature-Driven Dissolution of Nanoalloyed Catalyst During Ink Preparation and Membrane Electrode Assembly Fabrication

Author

Ronovský, Michal, primary, Dunseath, Olivia, additional, Hrbek, Tomáš, additional, Kúš, Peter, additional, Gatalo, Matija, additional, Polani, Shlomi, additional, Kubát, Jan, additional, Götz, Daniel, additional, Nedumkulam, Hridya, additional, Satori, Andrea, additional, Petrucco, Enrico, additional, Zepeda, Francisco Ruiz, additional, Hodnik, Nejc, additional, Strasser, Peter, additional, Bonastre, Alex Martinez, additional, and Drnec, Jakub, additional

Published
2024
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22. On a new species of titi monkey (Primates: Plecturocebus Byrne et al., 2016), from Alta Floresta, southern Amazon, Brazil

Author

Boubli, Jean P., Byrne, Hazel, da Silva, Maria N.F., Silva-Júnior, José, Costa Araújo, Rodrigo, Bertuol, Fabrício, Gonçalves, Jonas, de Melo, Fabiano R., Rylands, Anthony B., Mittermeier, Russell A., Silva, Felipe E., Nash, Stephen D., Canale, Gustavo, Alencar, Raony de M., Rossi, Rogerio V., Carneiro, Jeferson, Sampaio, Iracilda, Farias, Izeni P., Schneider, Horácio, and Hrbek, Tomas

Published
2019
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24. Bifunctional Pt–Ir nanoparticle catalysts for oxygen reduction and evolution reactions: investigating the influence of surface composition on the catalytic properties

Author

Blanco-Redondo, Lucinda, primary, Lobko, Yevheniia, additional, Veltruská, Kateřina, additional, Nováková, Jaroslava, additional, Mazur, Michal, additional, Darabut, Alina Madalina, additional, Hrbek, Tomáš, additional, Dopita, Milan, additional, Hraníček, Jakub, additional, Yakovlev, Yurii, additional, Matolínová, Iva, additional, and Matolín, Vladimír, additional

Published
2024
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25. Standardizing OER Electrocatalyst Benchmarking in Aqueous Electrolytes: Comprehensive Guidelines for Accelerated Stress Tests and Backing Electrodes

Author

Zlatar, Matej, primary, Escalera-López, Daniel, additional, Rodríguez, Miquel Gamón, additional, Hrbek, Tomáš, additional, Götz, Carina, additional, Mary Joy, Rani, additional, Savan, Alan, additional, Tran, Hoang Phi, additional, Nong, Hong Nhan, additional, Pobedinskas, Paulius, additional, Briega-Martos, Valentín, additional, Hutzler, Andreas, additional, Böhm, Thomas, additional, Haenen, Ken, additional, Ludwig, Alfred, additional, Khalakhan, Ivan, additional, Strasser, Peter, additional, and Cherevko, Serhiy, additional

Published
2023
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38. Investigation of Ir(Ox)-Ru(Oy) thin-film catalysts for oxygen evolution reaction in proton exchange membrane water electrolyzers

Author

Hrbek, Tomáš, Kúš, Peter, and Bystroň, Tomáš

Subjects
elektrolyzér|reakce vzniku kyslíku|magnetronové naprašování|tenkovrstvý katalyzátor|iridium-ruthenium, electrolyzer|oxygen evolution reaction|magnetron sputtering|thin-film catalyst|iridium-ruthenium
Abstract

The main focus of this master thesis is the investigation of the anode catalysts for the Proton Exchange Membrane Water Electrolyzers (PEM-WEs). PEM-WEs play a pivotal role in the hydrogen economy concept as they allow water decomposition into oxygen and hydrogen. However, their operation requires expensive noble metal catalysts, i.e., iridium or platinum. This issue has yet to be solved to mass-produce PEM-WEs. Consequently, our main objective is to reduce the amount of iridium on the anode of PEM-WEs. We addressed this objective by two distinct approaches: morphological and chemical. With the morphological approach, plasma etching of the membrane and the magnetron sput- tering of CeO2 served to increase the membrane's active surface. Hence we improved the catalysts utilization. With the chemical approach, we focused on the catalyst itself. Thus, we replaced the pure iridium catalyst with a bimetallic iridium-ruthenium one. Therefore, the activity of the catalyst was enhanced while its price got reduced. To ex- plain and describe the catalyst's behavior, we used various electrochemical methods and surface analysis techniques. Finally, we combined both approaches to obtain one active, stable, and low-iridium-loading anode catalyst for PEM-WE.

Published
2021

43. Study of the effect of thin film catalyst morphology on efficiency of water electrolyzer with proton conducting membrane

Author

Hrbek, Tomáš, Matolín, Vladimír, and Nováková, Jaroslava

Subjects
leptaná membrána PEM, Ir vs. IrO2, magnetronové naprašování, electrolyzer, magnetron sputtering, elektrolyzér, thin-layer catalyst, tenkovrstvý katalyzátor, etched membrane PEM
Abstract

Title: Study of the effect of thin film catalyst morphology on efficiency of water electrolyzer with proton conducting membrane Author: Tomáš Hrbek Department: Department of Surface and Plasma Science Supervisor: prof. RNDr. Vladimír Matolín, DrSc., Department of Surface and Plasma Science Abstract: This bachelor thesis deals with the possibility of reducing the amount of noble metals in catalytic layers of proton exchange water electrolyzer (PEM-WE). The PEM-WE is an important unit of hydrogen economy as it allows storage of excess energy from renewable sources in the form of chemical energy. In the first part, etched membrane electrolyzers were prepared and tested, membrane etching is a previously unpublished procedure leading to a reduction of the amount of catalyst. Etched membranes were studied by scanning electron microscopy and, consequently tested in real working conditions in electrolyzers. In the second part of the work; Ir and IrO2 were compared as catalysts for PEM-WE anode. Their in-cell performance was tested directly in the electrolysers and in controlled condition by rotating disk electrode. Keywords: electrolyzer, magnetron sputtering, thin-layer catalyst, etched mem- brane PEM, Ir vs. IrO2

Published
2019

45. Application for an appeal review on the points of law in civil procedure

Author

Hrbek, Tomáš, Winterová, Alena, and Smolík, Petr

Subjects
Dovolání, Admissibility of the Application for an appeal review, Legal remedies in the civil procedure, Application for an appeal review, Přípustnost dovolání, Opravné prostředky v civilním řízení
Abstract

This thesis focuses on the effective regulation of the application for an appeal review reflecting it from the point of its value background, historical development and the relevant case-law. With an intention to point out the necessary backing for the critical assessment of specific elements and the present form of the application for an appeal review in a civil procedure as a whole, the thesis deals with the theoretical basis of the legal remedies in the civil procedure and with the role of the application for an appeal review in their effective regulation. In the thesis, particular attention is paid to the purposes of the application for an appeal review, i.e. to the unification of the case-law and the protection of the rights of an individual in a particular case, as far as to their relation to the legal certainty resulting from the final decisions, which the use of the application for an appeal review undermines. The thesis contains the general conclusions on the relationship between these values and the conclusions on the appropriateness of the regulation of the particular elements of the application for an appeal review, which are connected with these values. A special chapter of this thesis deals with the history of the appeals focusing only on that facts and legal constructs, which are...

Published
2016

49. Diferenční a pseudodiferenční filtrační obvody

Author

Jeřábek, Jan, Bečková, Zuzana, Hrbek, Tomáš, Jeřábek, Jan, Bečková, Zuzana, and Hrbek, Tomáš

Abstract

Bakalářská práce se zabývá analogovými kmitočtovými filtry, pracující v diferenčním a~pseudodiferenčním režimu. Je zaměřena zejména na aktivní filtry druhého řádu, které využívají moderních aktivních prvků. U konkrétních řešení je analyzována možnost řízení parametrů filtru. Dále se text zabývá problematikou návrhu plně diferenčních filtrů a~transformací z nediferenčních filtrů. V práci jsou analyzovány tři konkrétní filtrační řešení se kterými jsou provedeny ideální simulace a simulace pomocí modelů třetího řádu. Pro jedno filtrační řešení je zkonstruován plošný spoj, jeho parametry změřeny a~porovnány se simulacemi., This bachelor thesis deals with analog frequency filters operating in differential and pseudodifferential mode. It is focused on active filters second order that use modern active elements. For specific solution is analyzed the ability to control filter parameters. It also deals with the design of fully differential filters and transformations from non-differential filters. The thesis analyzes three specific filtering solutions with which ideal simulations and simulations using third order models are performed. A printed circuit is constructed for one filter solution, its parameters are measured and compared with simulations.

50. Diferenční a pseudodiferenční filtrační obvody

Author

Jeřábek, Jan, Bečková, Zuzana, Hrbek, Tomáš, Jeřábek, Jan, Bečková, Zuzana, and Hrbek, Tomáš

Abstract

Bakalářská práce se zabývá analogovými kmitočtovými filtry, pracující v diferenčním a~pseudodiferenčním režimu. Je zaměřena zejména na aktivní filtry druhého řádu, které využívají moderních aktivních prvků. U konkrétních řešení je analyzována možnost řízení parametrů filtru. Dále se text zabývá problematikou návrhu plně diferenčních filtrů a~transformací z nediferenčních filtrů. V práci jsou analyzovány tři konkrétní filtrační řešení se kterými jsou provedeny ideální simulace a simulace pomocí modelů třetího řádu. Pro jedno filtrační řešení je zkonstruován plošný spoj, jeho parametry změřeny a~porovnány se simulacemi., This bachelor thesis deals with analog frequency filters operating in differential and pseudodifferential mode. It is focused on active filters second order that use modern active elements. For specific solution is analyzed the ability to control filter parameters. It also deals with the design of fully differential filters and transformations from non-differential filters. The thesis analyzes three specific filtering solutions with which ideal simulations and simulations using third order models are performed. A printed circuit is constructed for one filter solution, its parameters are measured and compared with simulations.

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